Climate Guide: Key concepts and definitions (continued)

This RIBA Climate Guide is a holistic guide for you and your practice to deliver sustainable projects and meet RIBA's 2030 Climate Challenge.

Chapters one to four are available separately.

Chapter 5: Energy and Carbon:

Net zero energy, net zero carbon, zero carbon, carbon neutral should be carefully distinguished as (WLCN, 2022):

· Concerning operational energy uses, a net zero (operational) carbon asset is one where no fossil fuels are used, all the energy use (Module B6) has been minimised, meets (at a minimum) the local energy use target (e.g. kWh/m²/year) and all the energy use is generated on- or offsite, using renewables that demonstrate ‘additionality’. All direct emissions from renewables and any upstream emissions are ‘offset’. (*Direct emissions could include CH₄ and N₂O emissions from the combustion of biomass and biodiesel fuels. Upstream emissions include direct and indirect emissions from energy generation and distribution, Well-to-Tank (WTT) (which are upstream, or indirect) emissions for energy consumed in the building and from energy generation, as well as distribution.)

· A net zero (operational) carbon infrastructure asset is one where the sum total of greenhouse gas (GHG) emissions, as aligned with the scope of Operational Expenditure (or OpEx) as determined by the asset owner’s preference, is one where no fossil fuels are used, all energy use has been minimised, meets the local energy use target and all energy use is generated on- or offsite, using renewables that demonstrate ‘additionality’, meets local carbon targets (e.g. kgCO₂e/m²) and with additional ‘offsets’, equals zero.

· Concerning operational water uses, a net zero (operational) carbon asset is one where water use (Module B7) is minimised, meets local water targets (e.g. litres/person/year) and where those GHG emissions arising from water supply and wastewater treatment are offset.

• A net zero embodied carbon, or net zero life cycle embodied carbon asset is one where the sum total of GHG emissions and removals over an asset’s life cycle (Modules A0–A5, B1–B5 and C1–C4) are minimised, meet local carbon targets (e.g. kgCO₂e/m²) and with additional ‘offsets’, equals zero.
• A net zero (whole life) carbon asset is one where the sum total of all asset-related GHG emissions, both operational and embodied, over an asset’s life cycle (Modules A0–A5, B1–B8, C1–C4) are minimised, meet local carbon, energy and water targets and with residual ‘offsets’, equals zero. (*To meet the requirements of net zero (whole life) carbon, it is necessary to also meet the definitions individually for ‘Net Zero Upfront Carbon’, ‘Net Zero Capital Carbon’, ‘Net Zero Operational Carbon’ (for energy, infrastructure and water, as applicable).)
• A net zero upfront carbon asset is one where the sum total of GHG emissions, excluding biogenic carbon, from Modules A0 to A5 is minimised, meets local carbon targets (e.g. kgCO₂e/m²) and with additional ‘offsets’, equals zero. (*Net zero upfront carbon can be claimed at Practical Completion, based on actual values, subject to verification and residual offsets.)
• A net zero capital carbon infrastructure asset is one where the sum total of GHG emissions are aligned with the scope of Capital Expenditure (CapEx) as determined by the asset owner’s preference, is minimised, meets local carbon targets (e.g. kgCO₂e/m²) and with additional ‘offsets’, equals zero. (*Biogenic Carbon should only be accounted for where all modules A, B and C are included.)
• A carbon neutral asset is one where all carbon emissions are balanced with offsets, based on carbon removals or avoided emissions.
• A net zero in-use carbon asset is one where on an annual basis, the sum total of all asset-related GHG emissions, both operational and embodied (Modules B1–B8), are minimised, meet local carbon, energy and water targets or limits and with residual ‘offsets’, equals zero. (*Net zero in-use carbon can be claimed annually.)
• Absolute zero carbon is eliminating all carbon emissions without the use of ‘offsets’.

(*A building that is ‘net zero carbon in design’ is one that is designed to be net zero carbon based on generic values (i.e. typical industry average quantities based on ‘Environmental Product Declarations (EPD)’ or equivalent data from accepted industry databases), but it does not have actual embodied, operational performance data to allow verification of net zero carbon status. A ‘net zero carbon enabled’ building is also one that is designed to be ‘net zero carbon in-use’, but it does not have actual in-use, or end-of-life performance data to allow verification of net zero carbon status. At Project Completion, an asset is potentially ‘net zero carbon enabled’ to allow for the occupier to achieve a ‘net zero carbon in-use/occupation’, subject to actual usage data and metered consumption, as well as residual, associated offsets. At concept design stage, an asset can be predicted to be net zero, based on generic values, which are assessed using estimated quantities, and appropriate – if available national, if not regional or global – carbon factors from accepted industry databases (source and the territorial scope must be stated). When a building is called ‘net zero carbon’, it means that that building is verified as ‘net zero carbon’, using actual, measured data and a third-party-verified assessment. Actual values or as-built values are assessed using actual quantities and carbon factors from Environmental Product Declarations (EPDs) of the actual products/systems used (to be adapted to the project location; with transport including actual, on-site waste quantities, waste transportation and treatment).

‘Thermal Mass’ is a material’s capacity to absorb heat, store it and slowly release it, extending indoor comfort hours, reducing operational costs and enhancing durability of a structure. (*It is determined by a material’s specific heat capacity (to store heat), thermal conductivity (to transfer/release heat), size and density (heavy-weight materials can store more heat than lightweight ones). The higher the material’s specific heat capacity, thermal conductivity and density are the higher the thermal mass of that material is and the greater of a ‘thermal lag’ it will provide (or the longer it will take to heat up).

A ‘Brise-soleil’ is an architectural feature, often used as an external shading element, to deflect sunlight. (*It uses a series of angled, horizontal, vertical, latticed or patterned louvre fins, or blades, specifically arranged to control the amount of sunlight (i.e. solar heat gains and daylight) entering a building.)

‘Carbon Capture’ is the process, by which carbon dioxide is removed from the atmosphere and stored within a material (e.g. stored as ‘biogenic carbon’ in ‘biomass’ by plants/trees through photosynthesis and other processes).

‘Carbon Sequestration’ is the process by which carbon dioxide is removed from the atmosphere and stored within a material (e.g. stored as ‘biogenic carbon’ in ‘biomass’ by plants/trees through photosynthesis and other processes).

‘Carbonation/Calcination’ are processes that artificially accelerate the ‘carbon sequestration’ process through injecting carbon dioxide into solid materials. (*An example of carbonation in building construction materials is Portland cement, concrete and carbonated aggregates.)

The quality of renewable energy procurement is defined by its ‘energy attribute certificate’, which evidences that electricity is produced from renewable sources (e.g. sun, wind, hydropower), and that provides ‘additionality’.

‘Life Cycle Assessment (LCA)’ is typically a ‘Cradle-to-Grave’ methodology used to calculate a building, product and/or a service’s overall environment impact throughout its entire life.

Ventilation is the intentional introduction of natural, outdoor air into the building in a controlled manner, to remove heat and increase air quality. (*It can take place in the form of single-sided, cross/double-sided, (buoyancy-driven) stack (with solar chimneys where additional height can be provided) and down-draught, as seen in the wind catchers/towers of the Middle East.)

Microclimate is a set of localised, atmospheric conditions (within a built environment) that vary from its macro/surrounding environment.

Daylighting is the admission of natural light into a building, in a controlled manner, to reduce the need for artificial lighting. (*It can be from a direct (from the sun), indirect (from reflective surfaces) and/or a diffused light (from a skylight), and it must be carefully designed to mitigate against glare risk indoors which is a significant source for ‘visual discomfort’.)

Heat Loss is the measure of total heat transfer from inside to outside of a building which can happen in the form of convection, conduction and/or radiation. (*It is directly impacted by the performance of the building fabric (i.e. the poorer the thermal insulation of a building is, the greater the heat loss there will be). It is measured in kW.)

‘Form Factor’ is a measure of a building’s total thermal envelope surface area to the treated/conditioned, indoor floor area.

‘Surface Area/Volume (S/V)’ represents the external surface area of a building in relation to its internal volume (i.e. conditioned space). (*The lower the S/V ratio is, the lower the building’s energy demand will be.)

‘Window-to-Wall Ratio (WWR)’ is the ratio of the window/glazed areas on a building’s facade to that of the entire facade/wall area above grade.

[Solar] Shading is a method by which solar radiation can be mitigated in a building. (*It can be provided in the form of external, facade elements, internal blinds, as well as solar technology (with films/coatings added onto glass, such as low-e coating). It must be defined and detailed to effectively respond to different conditions each building orientation will present, and it must balance daylight access and solar heat gain mitigation well.)

Solar Heat Gain is the increase of a space’s thermal energy due to direct/indirect absorption of incident (short wave) solar radiation.

Airtightness is preventing air leakage (caused due to wind, stack effect and/or combustion), through construction gaps and flow of moisture, as well as heat, through a building’s envelope.

A ‘Thermal Bridge’, also known as a ‘Cold Bridge’ – is a localised, weak spot in a building (within the insulation layer at various junctions/interfaces) where a building’s internal elements connect to its outside layer, and where heat dissipates.

A ‘Thermal Break’ is a low, conductive material, placed in between two materials to slow down heat transfer from one to another.

Albedo is a measure of a surface’s reflectivity. (A high albedo material is able to reflect solar radiation and avoid accumulation of heat build-up from solar radiation. Light-coloured stone is a good example of a high albedo material – when compared to asphalt, which has a very low albedo, hence results in surface warm-up, especially during the hot periods.)

A Regularly Occupied Space is a space that is occupied minimum one continuous hour/day (IWBI, 2021).

‘Thermal Lag’ is the time of exterior–interior heat flow through a building’s external envelope. (*Its times are influenced by temperature differentials (ΔT) between each face, the material’s thickness, its conductivity, density, texture, colour and surface coatings, as well as its exposure to air movement and speed.)

Heat pumps are a group of devices that can heat or cool a building – in a low carbon and energy-efficient manner – by transferring thermal energy from outside, using the refrigerant cycle. (*There are three types of heat pumps: air-source, ground-source and water-source. Water-source heat pumps absorb heat from a local water source (such as a lake, river, aquifer, etc.), and can be ‘open-loop’ (requiring water extraction from and discharge back to the main source) or deep, ‘closed-loop’ (which can also be used for electricity generation).)

Similar to a battery, a [Solar] Thermal Storage captures surplus energy generated by the solar electricity (i.e. ‘Photovoltaic (PV)’) panels, and stores it for use at a later time in the day.

An ‘Ambient Loop’ is a heat-sharing network that enables low temperature heat sharing between different floors in the same building and/or between different buildings. (*Coupled either with ground (passive) or connected to a communal air-source heat pump (active), it operates at a low temperature (at 15 ^oC–30^oC instead of the typical 60^oC–90^oC), minimising the heat distribution loss. An ‘ambient loop’ can also be used for cooling, removing excess heat from one space, and taking the removed heat to elsewhere where heating is needed.)

District Energy Networks are networks of highly insulated pipes (buried into the ground across a large site) that transfer steam or hot water from an energy centre into multiple buildings, for heating and/or cooling purposes. (*The energy source of the district network may vary from biomass to electricity to coal, and it can only be low carbon if supplied by a centralised, low carbon technologies, such as large-scale heat pumps.)

An Air-source Heat Pump, placed outside of a building, absorbs heat from outside air and supplies it to radiators, underfloor heating systems and/or as hot air, directly into a space.

A Ground-source Heat Pump, with fluid-filled pipes embedded in the ground in boreholes or horizontal trenches, absorbs heat from the ground, which is heated by the sun. This heat is then transferred into a building, to supply space heating and/or domestic hot water demand.

‘Solar Thermal Collectors’ are high-efficiency evacuated tubes, or flat plates that absorb heat from the sun to produce domestic hot water, which is then stored in a highly insulated cylinder. They can additionally be used to collect heat for electricity generation, space heating or cooling (with an absorption chiller). (*The collectors can either be concentrating (where the area intercepting solar radiation is greater than the area absorbing solar energy/radiation) or non-concentrating (where the area intercepting solar radiation is the same as the area absorbing solar energy/radiation).)

A Cooling Tower is a heat exchanger that removes heat, using water to transfer processed heat into the atmosphere. (*In buildings, it is primarily used for heating, cooling, ventilation and air conditioning, and it can provide a cost-effective, and energy-efficient operation of cooling systems.)

A Radiant Ceiling Panel is a metal panel that circulates hot or cold water through concealed copper tubing (attached on the back of the panel) to provide heating and/or cooling. (*Typically used in commercial buildings, these ceiling panels provide cost-effective heating/cooling, without producing any noise and/or draughts.)

A [Active] Chilled Beam is a type of heating, ventilation and air-conditioning (HVAC) system, designed to heat and/or cool buildings. (*It has pipes of water running through a ‘beam’, either integrated into a suspended ceiling system, or as a stand-alone element that sits slightly away from the ceiling.)

‘Thermally Activated Building System (TABS)’ is a low temperature heating and high temperature cooling system where water-filled pipes are embedded within concrete slabs, to provide radiative heating/cooling into a space.

At Displacement Ventilation, air is supplied at a low velocity at 20^oC, to maintain occupant comfort. (*This system is most effective in buildings with high floor-to-ceiling heights. The supplied outdoor air in this system, would need to be dehumidified in tropical/sub-tropical climate regions.)

A Ventilated Facade is a facade system with a ventilated ‘air gap’ in between the external cladding, and the rear insulation layer.

Air Handling Units (AHUs) are devices that are used to condition and distribute air within a building, as part of a heating, ventilation and air-conditioning (HVAC) system. (*They are commonly used in medium to large, commercial and/or industrial buildings. They can be located either in the basement, on roof or on floors, and typically serve up to ten floors (up and down the building).)

A Fan Coil Unit (FCU) is a heating/cooling system, which serves the space that is located in and typically works in conjunction with a central AHU, which supplies ventilation air from outside. (*A FCU can be noisy and have high operational costs due to its regular maintenance need.)

‘Mechanical Ventilation with Heat Recovery (MVHR)’ is a ventilation system that provides fresh, filtered air into a building, using the recovered energy that has already been used to heat the building. (*It is typically used in residential buildings and required by the ‘Passivhaus Standard’ (due to its high, 80% efficiency).)

Heat Recovery is the process through which heat (from the exhausted air out of the building) is captured and through a heat exchanger, is fed back to the incoming, supply air (from outside) which serves the occupied spaces.

‘Dedicated Outdoor Air System (DOAS)’ is a type of heating, ventilation and air-conditioning (HVAC) system that has a dedicated system for delivering outdoor air ventilation, both for latent and sensible loads, and a parallel system for mainly the (remaining) sensible heat loads inside a building. (*Commonly installed outside, it brings fresh, dehumidified and cooled (in summer) and heated (in winter) air from the outside to inside, independently from the heating and/or cooling of the building).

‘Underfloor Air Distribution System (UFAD)’ is a method for delivering space conditioning through an underfloor plenum, beneath a raised floor, as part of the building’s heating, cooling and air-conditioning (HVAC) system. It is commonly used in offices, or in other commercial buildings, to bring conditioned air directly into a building’s occupied zone.

A ‘Building Integrated PV (BIPV) Panel’ is a solar/photovoltaic material (often in the form of a roof tile, window or a facade panel) that replaces conventional building materials, to generate energy on site.

A Clerestory Window is a high-level window (above human eye level) that is used to bring light deep into a space. (*It can also be used for bringing fresh air inside a building.)

A ‘Light Shelf’ is an architectural feature that is used to reflect daylight deep into a space. (*It comprises of a light-coloured and/or reflective, horizontal surface that can either be fixed externally (which is usually more effective), internally, or both, depending on its optimum function in providing an even illumination gradient inside a space.)

‘Operational Carbon’ Emissions’ of a building – associated with energy use (Module B6) – are the greenhouse gas (GHG) emissions arising from all energy consumed by an asset in-use, over its life cycle. ‘Operational Carbon’ emissions – associated with water use (Module B7) – are those GHG emissions arising from water supply and wastewater treatment for an asset in-use, over its life cycle. The scope of ‘Operational Carbon’ GHG emissions of an infrastructure asset are those that align with the scope of Operational Expenditure (OpEx) as determined by the asset owner’s preference. (*Modules A, B1–B5 and C should be clearly identified as ‘Capital’ or ‘Operational’ within the scope. Modules B6 and B7 are always ‘Operational’) (WLCN, 2022).

‘Embodied Carbon’ Emissions’ of an asset – also known as ‘Life Cycle Embodied Carbon Emissions’ – are the total greenhouse gas (GHG) emissions and removals associated with materials and construction processes throughout the whole life cycle of an asset (Modules A0–A5, B1–B5, C1–C4 with A0 assumed to be zero for buildings) (*Demolition of a previous structure, or building should be separately identified and included within Module A5) (WLCN, 2022).

‘Upfront (Embodied) Carbon’ emissions of a building are the greenhouse gas (GHG) emissions associated with materials and construction processes up to practical completion (Modules A0–A5). (*Upfront carbon excludes the biogenic carbon sequestered in the installed products at practical completion. Demolition of a previous structure, or building should be separately identified and included within Module A5) (WLCN, 2022).

‘Biogenic Carbon’ refers to the carbon removals associated with ‘carbon sequestration’ into ‘biomass’, as well as any emissions associated with this sequestered carbon. (*Biogenic carbon shall be reported separately if reporting only ‘upfront carbon’ but shall be included if reporting ‘embodied carbon’ or ‘whole life carbon’) (WLCN, 2022).

The scope of ‘Capital Carbon’ (greenhouse gas) GHG emissions of an infrastructure asset are those that align with the scope of Capital Expenditure (or CapEx) as determined by the asset owner’s preference. (*Modules A, B1–B5 and C should be clearly identified as ‘Capital’ or ‘Operational’ within the scope) (WLCN, 2022).

‘Other Operational Processes’-related emissions (Module B8) are those (greenhouse gas) GHG emissions associated with the operation and use of an asset that are not included in Modules B1–B7 but are required to enable it to operate and deliver its service (WLCN, 2022).

‘User Carbon’-related emissions (Module B9) are those that arise from ‘users’ utilisation of infrastructure and the service it provides during operation’ (WLCN, 2022). These emissions are not included in PAS 2080 – Carbon Management in Infrastructure, which is the global standard for managing infrastructure carbon (WLCN, 2022).

‘Beyond Building Life Cycle Stage’ captures the loads, as well as the benefits beyond the typical ‘Cradle-to-Grave’ life cycle of a building. (*It allows accounting for the recycling potential of the building’s materials and/or the exported energy) (Wastiels et al., 2014).

‘Carbon Capture and Storage (CCS)’ is a series of technologies that capture carbon dioxide, transport it (usually via pipelines) and store it (typically in geological sites on land and undersea), before it enters the atmosphere and contributes to ‘global warming’. (*The economics, commercial viability and scalability of the CCS technologies are still being studied.)

‘Direct Air Capture (DAC)’ is a technology that extracts carbon dioxide (CO₂) from the atmosphere and sells it to companies that produce carbonated drinks or CO₂-absorbing concrete. (*This technology can also turn captured CO₂ into synthetic fuels to replace diesel, gasoline or natural gas. The longer-term (such as use in materials) or permanent (such as in injections to the deep geological formations) provide the greatest benefits from this technology).

‘Cross-Laminated Timber (CLT)’ is a type of engineered, panelised wood product that is manufactured by laminating layers of solid-sawn lumber with a high-performance glue.

‘Glued Laminated Timber (GLT)’ – also known as ‘Glulam’ – is a type of structural engineered wood product that is manufactured by gluing layers of dimensional lumber together with durable and moisture-resistant, structural adhesives.

‘Residual Emissions’ are emissions that remain after a built asset, or an organisation have implemented all technically and economically feasible solutions to reduce emissions in all scopes and from all sources. (*The quantity of residual emissions is estimate through to 2050, and identified in the 2050 trajectory) (C40 Cities, 2020).

Offsetting is ‘reducing [greenhouse gas] GHG emissions (including through avoided emissions) or increasing GHG removals through activities external to an actor, in order to compensate for GHG emissions, such that an actor’s net contribution to global emissions is reduced’. (*Typically arranged through a marketplace for carbon offset credits, or other exchange mechanisms, offsetting claims are only valid under a rigorous set of conditions that ensure the involved reductions/removals are additional, not overestimated and exclusively claimed) (Race to Zero, 2022).

‘Scope 3’ Emissions capture all the indirect emissions, such as business travel, purchases of goods, energy procured for tenants or waste disposal that are not addressed in ‘Scope 2’.

‘Additionality’ is the procurement of renewable energy for the asset’s use which results in new installed, renewable energy capacity that otherwise would not have occurred, had the intervention not taken place (WLCN, 2022). (*For example, ‘Direct Air Carbon (DAC)’ capture has ‘additionality’, whereas the restoration of a forest that is not in danger does not.)

‘Scope 1’ Emissions cover emissions directly generated by the built environment and/or its related activity, such as the emissions from a central plant, or boilers and/or the construction vehicles on a project site.

‘Scope 2’ Emissions include indirect emissions that are a result of electricity, heating and/or cooling purchases.

A ‘Renewable Energy Certificate (REC)’ is a market-based mechanism (in the USA) that is created by state, or regulatory action to make it easier to track and trade renewable energy. (*It represents the environmental attributes of a renewable energy project (e.g. solar, wind), and it can be sold separately or together with the electricity that the project produces. One megawatt-hour (MWh) of electricity that is produced by a qualifying renewable energy project generates one REC) (Thomson Reuters Practical Law, 2022).

Double Counting of Carbon is the process where two parties assert the same carbon emissions’ reduction, or removal for mitigation and/or compliance purposes.

‘Offset Credits’ – also known as ‘Carbon Offset Credits’ are tradable/transferable, non-tangible instruments (certified by a government, or an independent certification body) to an internationally recognised carbon accounting standard. (*They typically represent one tonne of carbon dioxide-equivalent (CO₂e), or an equivalent amount of other (greenhouse gas) GHGs, that is reduced, avoided or sequestered by a project) (Carbon Offset Guide, 2022).

‘Clean Development Mechanism (CDM)’ is an international carbon finance scheme and a project-based mechanism (under the Kyoto Protocol, Article 12) that allows emissions-reduction projects in developing countries, to earn ‘Certified Emission Reduction (CER)’ credits – each equivalent to one tonne of carbon dioxide (CO₂) avoided or removed from the atmosphere. These CERs can be traded and sold, as well as used by industrialised countries to meet a part of their emissions’ reduction targets under the Kyoto Protocol.

‘Bioenergy with Carbon Capture and Storage (BECCS)’ is the process of removing carbon dioxide (CO₂) from the atmosphere by extracting ‘bioenergy’ from ‘biomass’, and capturing CO₂ from it, then storing it.

‘Time Value of Carbon’ is the concept where (greenhouse gas) GHG emissions reduced today are more critical than emissions reduced later, due to increasing risk associated with immediate and scalable climate inaction.

A Biotope – often used synonymously to ‘Habitat’ – is a geographical region, in which the biological environment is uniform in its environmental conditions and the distribution of the flora and fauna that live in it.

Bitumen – also known as ‘asphalt’ – is a sticky, highly viscous and waterproof binding agent produced from petroleum, commonly used for paving and roofing.

‘Biochar’ is a solid, organic material (charcoal-like residue made of carbon and ashes) that is ‘obtained from thermochemical conversion of “biomass” in an oxygen-limited environment’ (International Biochar Initiative, 2015). (*Often used as a soil additive, ‘biochar’ can sequester carbon in the ground for centuries, while also improving soil fertility (especially in degraded, tropical soils), increase agricultural productivity and improve water quality.)

‘Integrated Project Delivery (IPD)’ is a project delivery method that involves all the key stakeholders to continuously build efficiency (and in the end, ‘lean construction’) throughout a project’s entire design and construction phases. (*Coupled with an iterative design process, IPD can increase a building’s delivery speed to market by >30% (Facilities Net, 2021).)

A ‘Feedback Loop’ is a process in which some, or all outputs of a system are used as inputs in some or all parts of the system’s future operations.

‘Energy Use Intensity (EUI)’ is the total amount of energy that is used in a building in a year, divided by its floor area. (*It is often considered as a measure of a building’s energy efficiency. RIBA 2030 Climate Challenge and LETI Climate Emergency Design and Retrofit Guides are some of the industry sources that define EUI targets (in kWh/m²/year) for different building uses, to achieve net zero carbon.)

‘Spatial Daylight Autonomy (sDA)’ is a measure of daylight availability within a space. (*It is expressed in percentage of floor area that receives a specific amount of daylight which is defined as ‘minimum 300lux for at least 50% of the annual occupied hours (8am–6pm) on the horizontal work plane (760mm above the finished floor, or work plane height) for >55% of regularly occupied floor area’. SDA is defined by the IES Lighting Measurements (LM) 83-12, Approved Method: IES Spatial Daylight Autonomy (sDA) and Annual Sunlight Exposure (ASE), and noted in the relevant credit/feature of LEED BD+C: New Construction – EQ-Indoor Environmental Quality, Daylight and WELL Building Standard – Light, L06 Daylight Simulation).

‘Visible Light Transmittance (VLT)’ is a measure of the amount of visible light that passes through a lens or a glazed material. (*It is expressed in percentages and used as a rating for glass/window films. VLT ranges from 10% (highly reflective, or dark/tinted glass) to 90% (clear glass), and it is influenced by the glazing type, glass coating/s and the number of glass panes.)

‘Unified Glare Rating (UGR)’ is a measure of the glare level within a space. (*Originally proposed by Kai Sørensen in 1987, it ranges from 5 to 40, with the lower rating representing less glare. EN 12464-1 – Lighting and Lighting, Lighting of Work Places, Indoor Work Places standard defines UGR values for typical environments/uses (e.g. UGR <19 for reading, writing, training, and meeting activities). A UGR <10 will produce minimal glare and a UGR ≥30 would severely impair visibility (JCC Lighting Products, 2022).)

‘Formaldehyde’ is a strong-smelling, colourless and flammable chemical (with a formula of CH₂O), which is used in building materials (e.g. laminate flooring), insulation, the resins of the manufactured, composite wood products (i.e. hardwood plywood, particleboard and medium-density fibreboard), household products (e.g. glues, permanent press fabrics, paints, coatings, finishes), preservatives (used in cosmetics and medicine), fertilisers and pesticides. (*It is also a gas that is released from un-vented, fuel-burning appliances (e.g. gas stoves), during tobacco smoking, and also in nature, through ‘biomass’ combustion (e.g. forest and bush fires) and/or decomposition. WELL Building Standard – Air, A01 Air Quality defines the maximum formaldehyde threshold (in µg/m³) in occupiable spaces.)

‘Particulate Matter (PM)’ – also called ‘Particle Pollution’ – is a mixture of particles (tiny pieces) of solids, or liquids found in the air that are directly emitted from a source (such as construction sites, unpaved roads, smokestacks, tobacco smoke, candles, fires, cleaning products and air fresheners). (*It is classified according to its size as PM_2.5 (for fine, inhalable particles with a diameter of ≤2.5μm) and PM₁₀ (for inhalable particles with a diameter of ≤10μm). This classification is used in concentration measurements, the unit of which is µg/m³. WELL Building Standard – Air, A01 Air Quality defines the maximum PM thresholds in occupiable spaces.)

‘Sound Transmission Class (STC)’ is a rating of sound isolation of a building assembly, measuring its effectiveness in reducing sound transmission between spaces. (*First introduced in 1961, it is a widely used rating for interior partitions, doors, windows, floors and ceilings. The higher the STC rating is, the better sound insolation the assembly is to achieve. The LEED BD+C: New Construction – EQ-Indoor Environmental Quality, Acoustic Performance credit and the WELL Building Standard – Sound, S03 Sound Barriers feature define the minimum STC thresholds (in decibels (dB) and for different uses and functions) in occupiable spaces.)

‘Reverberation Time (RT)’ is the time (in seconds) required for the sound in a space to decay by 60 decibels (dB), when a source suddenly stops. (*It is ‘a function of the room volume, surface area and absorptive properties surface finishes’ (IWBI, 2022). WELL Building Standard – Sound, S04 Reverberation Time defines the RT ranges for different space types.)

‘Noise Rating (NR)’ Curves is a method for rating noise in occupied spaces, to determine acceptable indoor environments for speech communication, hearing preservation and annoyance, and it takes into account the frequency of the noise. (*Defined in ISO 1996-2 – Acoustics – Description, Measurement and Assessment of Environmental Noise, Part 2: Determination of Sound Pressure Levels, the curves range from NR 0 to NR 130 (against maximum sound pressure levels in decibels (dB)) where NR 30 is for example, identified as the maximum noise rating level in private dwellings, hospitals, theatres, cinemas and conference rooms).

‘Walk Score^®’ is a measure of a location’s walkability. (*Developed by a private company in 2007, carrying the same name, it is presented in numbers, which range from 0 to 100, where a 0–24 score means ‘car-dependent’ (i.e. almost all errands require a car), and 90–100 – labelled as ‘walker’s paradise’ – defines a location or a region all walkable (i.e. with amenities within 0.4km of its central location). The LEED BD+C: New Construction – LT-Location and Transportation, Surrounding Density and Diverse Uses and Fitwel – 1. Location credits outline minimum ‘Walk Score’ thresholds to be met to earn credits in these certification systems).

‘Bike Score^®’ is a measure of a location’ cyclability. (*It is calculated by measuring the cycle lanes, hills, destinations and road connectivity, as well as bike commuting mode share. Developed and launched by Walk Score in 2012, it is presented in numbers, which range from 0 to 100, where a 0–49 score means ‘somewhat bikeable’, and 90–100 – labelled as ‘biker’s paradise’ – defines a location or a region all cyclable (i.e. all daily errands can be accomplished on a bike).

‘Whole Life Carbon Emissions’ are the sum total of all asset-related greenhouse gas (GHG) emissions and removals, both operational and embodied, over the life cycle of an asset, including its disposal (Modules: A0–A5; B1–B7; B8 optional; C1–C4, and all including ‘biogenic carbon’, with A0 assumed to be zero for buildings). (*Overall ‘Whole Life Carbon’ asset performance includes separately reporting the potential benefit from future energy recovery, reuse and recycling (Module D1 and D2). Demolition of a previous structure, or building should be separately identified and included within Module A5) (WLCN, 2022).

A ‘Digital Twin’ is a digital model, virtually representing a physical object, or a system throughout its life. (*It is updated using real-time data, which is obtained from sensors that are fitted in the physical object/system’s vital areas of functionality, measuring its performance (e.g. its energy output, temperature, weather conditions). The gathered data is relayed to a processing system and then incorporated into the object/system’s digital model. This virtual model can be used to run performance analyses (through simulations) and generate potential improvements for the physical object/system.)

*For Table 2.01 (a) and (b) An overview of some of the key questions, outcomes, built environment ‘actors’ and outputs against the typical built environment project stages

A ‘Shoebox’ Energy Model is an initial, oversimplified energy model of a building (which is often represented in a rectangular box) to conduct an early design stage analysis of the building’s potential energy use in order to inform design decisions.

‘Life Cycle Analysis (LCA)’ – also known as ‘Life Cycle Assessment’ – is the process of estimating a building, product and/or a service’s overall environmental impact throughout its entire life (i.e. ‘Cradle-to-Grave’). (*The EN 15978 – Sustainability of Construction Works, Assessment of Environmental Performance of Buildings, Calculation Method standard provides a framework for appraising the built environment’s environmental impacts by setting out principles for whole life carbon assessments of built projects.)

‘Carbon Budget’ is the maximum allowable ‘cumulative amount of global carbon dioxide emissions that is estimated to limit global surface temperature to a given level above a reference period, taking into account global surface temperature contributions of other [greenhouse gasses] GHGs and climate forcers’ (IPCC, 2018).

‘Building End-of-Life (BEL) Report’ is a report produced at the end of a building’s useful life, to describe its condition (e.g. its structural state, the performance of its mechanical equipment, systems, envelope, interior fit-out materials/products), in order to determine the building elements’ future function – based on potential scenarios (i.e. whether they can be reused as they are (i.e. fulfilling the same function), or require upgrading (to improve performance), or must be ‘up-’ or ‘down-cycled’, or ‘recycled’ (to turn them into other materials/products that can serve ‘new’ functions), or discarded (i.e. sent back to manufacturers or treated as waste)). (*‘Building’ and/or ‘Material Passports’ can be useful tools to inform the BEL.)

A ‘Buy-back Scheme’ is an arrangement that allows companies to take responsibility for their product’s entire life cycle by reselling items (back to the suppliers, or manufacturers), and/or reusing them (by repairing them, or in a different function) to reduce waste which increases existing resource use and saves cost (through reuse of materials and/or secondary purchasing).

Value Engineering (VE) – also called ‘Value Analysis’ – is a systematic and disciplined procedure and review of goods, or products and services to improve their value (defined as the ratio of function to cost) by using an examination of function. (*It promotes the substitution of materials with lower cost alternatives, without sacrificing the functionality of the goods, or product and service.)

*For Figure 5.07 Diagram showing life cycle stages and modules over an asset’s entire life (adapted from WLCN, 2022)

User Activities-related emissions (Module B8) are those greenhouse gas (GHG) emissions associated with a user’s utilisation of the buildings or infrastructure during the use stage, excluding Modules B6 and B7 (PAS 2080, 2016). (*‘User Carbon’ (Module B9) which is infrastructure specific (as in PAS 2080, 2016), can be included within Module B8) (WLCN, 2022).

Chapter 6: Water

Water Scarcity is both a natural and a human-induced phenomenon, describing ‘the point at which the aggregate impact of all users impinges on the supply or quality of water under prevailing institutional arrangements to the extent that the demand by all sectors, cannot be satisfied fully’ (UN, 2013). (*Population faces ‘water scarcity’ when annual water supplies are <1,000m³ per person (UN Water, 2012). And perennial water shortages in cities are defined as having <100litres per person per day of sustainable surface and groundwater flow within their urban extent (McDonald et al., 2011).)

‘Water Stress’ is a measure of the total, annual average water demand of ‘blue water’ in a river basin, or sub-basin, and it occurs when the demand is between 10% and 20% more than the annual average water available in that basin. (*When the ratio is 20%–40%, the stress is measured as ‘medium stress’ and if it is more than 40%, it presents ‘severe stress’ (OECD (a), 2012). When a territory withdraws 25% or more of its renewable freshwater resources, that territory is categorised to be ‘water-stressed’ (FAO & UN Water, 2021).)

Greywater – also known as ‘Gray Water’ – is the wastewater generated in households (and other buildings) that come from sinks, showers, bathtubs, washing machines and dishwashers. (*It has lower levels of contamination when compared to ‘Blackwater’, but it still requires treatment (via biological (e.g. constructed wetlands and biodiverse landscapes), or mechanical systems (e.g. sand filtration and systems based on ultraviolet (UV) radiation) or bioreactors) before it can be reused for toilet flushing, landscape or crop irrigation (apart from edible plants) and other, non-potable uses.)

Blackwater – also known as ‘Sewage Water’, or ‘Brown Water’ – is the wastewater generated in households (and other buildings) that come from bathrooms and toilets, containing faecal matter and urine. (*In some countries (e.g. Australia), wastewater from kitchens and dishwashers are also considered blackwater due to contamination by grease and pathogens. Blackwater can be treated via biological (e.g. reedbeds), or chemical processes (e.g. aerated systems), and it requires disinfection before it can be reused for irrigation (although not for edible plants) and toilet flushing.)

Potable Water – also known as ‘Drinking Water’ – is the water that comes from surface and ground sources. (*It is treated for microorganism, bacteria, toxic chemicals, viruses and faecal matter before it can be used for drinking, food preparation/cooking purposes, among other uses.)

A Peri-urban area is the porous transition zone from rural to urban land, located at the edge/outskirts of urban areas.

‘Water Footprint’ is an environmental indicator, which measures the amount, or volume of fresh water (in litres or m³) used throughout the life cycle of a consumer item or service. (*It is a concept developed by Arjen Hoekstra at the IHE Delft Institute for Water Education in 2002. There are three types of ‘water footprint’: green (water from precipitation), blue (water from surface, or groundwater sources) and grey (fresh water required to assimilate pollutants in the production process)) (Iberdrola, 2022).

[Surface] Water Runoff is the (excess) water (from rain, storm, snow, sleet or hail) that flows from the roof and ground surfaces of the built environment to a drainage system, as it can no longer rapidly infiltrate in the soil. (*This can occur when the ground surface is impermeable (i.e. preventing water to be soaked into the ground), or if the soil is saturated (by water, to its full capacity) or when the rainfall is very heavy/intense.)

‘Water Availability’ is defined as the quantity of freshwater (on surface and at ground) that can be used for human activities, without significantly harming the ecosystems and other users (MyWaterEarth&Sky, 2022).

‘Water Proofing’ is increasing water reuse systems and storage capacities, and having better urban planning, improving risk management and enhancing citizen engagement in cities to reduce their exposure to flood risk (World Bank, 2016).

‘Climate-Smart Agriculture (CSA)’ is an approach to ‘buffer rural livelihoods from climate change and increasing rainfall variability’. (*It combines financing, technologies and smart policies to increase productivity, enhance resilience and reduce greenhouse gas emissions. Examples of CSA include drought-tolerant maize, dairy development, soil management, waste-reducing rice thresher and carbon finance (to restore crop fields), among others) (Zaveri et al., 2021).

‘Farmer-led Irrigation’ Development is a process, in which small-scale farmers (smallholders) intentionally ‘invest in, expand or improve their agricultural water use by adopting or developing small-scale, locally relevant and market-oriented solutions’ (IWMI, 2022).

‘Green Infrastructure (GI)’ is a strategically planned network of natural and semi-natural areas to deliver a wide range of ecosystem services (e.g. air quality, water purification, climate mitigation and adaptation, stormwater management, heat stress reduction, biodiversity increase and space for recreation) to support people and wildlife. (*Some of the GI types include urban forests, rain gardens, constructed wetlands, green/blue roofs and bioswales.)

‘Day Zero’ is the day when severe water restriction starts in a city, by largely switching off municipal water supplies. This is also the day when citizens would likely start queueing for their daily ration of water. (*It emerged as a term in discussions and planning for addressing Cape Town’s water crisis in 2018. It was used as a reference for the day ‘when water supplies in Cape Town’s reservoirs drop below 13.5%’ (Cassim, 2018).)

Grey Infrastructure is a human-engineered infrastructure for water resources (such as water and wastewater treatment plants, pipelines, dams, seawalls, roads, etc.).

A Faucet or Tap Aerator is a small screen – commonly inserted at the end of a faucet – to reduce the amount of water (coming out of the faucet), control the stream, prevent water splashing, maintain or improve water pressure, and reduce the risk of lead and debris exposure.

‘Net Positive Water’ is where all the water use has been minimised, meets (at a minimum) the local water use targets (e.g. litres/person/day or in other units/metrics), and all the water use is ‘generated’ on site, through rainwater harvesting, grey- and/or blackwater recycling and reuse.

A ‘95th Percentile Rainfall Event’ is the rainfall event with a participation depth that is greater than or equal to 95% of all the 24-hour storm events on an annual basis.

An Ultraviolet (UV) Filter is a water filtration solution that disinfects and purifies water, by exposing water-borne viruses and bacteria to UV lights, which kill them.

Sludge is a muddy deposit that is created by a natural event (e.g. mud in a riverbed after a flood), or a residual, semi-solid slurry that is produced as a by-product of the wastewater and sewage treatment processes (e.g. biosolids). (*It can be treated via thickening (which reduces the total volume of sludge to less than half of its original volume), digestion (which enables the organic solids to be decomposed into stable substances) and dewatering (which reduces the amount of water in it) processes.)

A Cesspool – also known as ‘Cesspit’ – is an underground holding tank for storing liquid waste and sewage.

A Constructed Wetland is an engineered water treatment system that utilises natural processes (involving wetland vegetation, soil and microbes) to treat and improve the water quality. (*It is an excavation on land that can treat grey- and blackwater, stormwater runoff and industrial wastewater, while also creating wildlife habitat.)

A Reedbed is a natural water filtration system that can be used to treat and improve water quality before it gets discharged into the environment. (*Found between water and land, it is a transitional habitat that utilises reeds’ ability to transport oxygen to the soil, encouraging microorganisms to digest the contaminants in the effluent) (Owlshall, 2018).

A ‘Waste Stabilisation Pond (WSP)’ is a natural wastewater treatment system that is made of a man-made depression – enclosed by earthen embankments, forming a shallow and open basin, with a large water body (i.e. pond) – where grey- and blackwater (or faecal sludge) are treated by natural processes (through bacteria), which reduce the wastewater’s organic content and remove pathogens from it. (*The ponds can be used individually or linked together in a series, to improve treatment capacity. There are three types of WSP: anaerobic, facultative and aerobic – each with different treatment and design characteristics (Spuhler, 2022).)

‘Non-revenue Water (NRW)’ is the water that is produced and is ‘lost’ (due to leaks or other) or unaccounted for before it reaches the customer.

Kinetic Energy is a form of energy that an object has due to its motion. (*There are five types of kinetic energy which are all measured in Joules: radiant, thermal, sound, electrical and mechanical. Walking, jumping or falling all involve kinetic energy.)

Silver Iodide is an inorganic compound that is a bright yellow solid but has a grey coloration due to the impurities of metallic silver that it commonly contains. (*With a formula of Agl, it is used in the formation of ice crystals in ‘Cloud Seeding’ operations. ‘Silver iodide exists naturally in the environment at low concentrations, and is not known to be harmful to humans or wildlife’ (DRI, 2020).)

Gabion is a modular containment system (called ‘Gabion Basket’, or ‘Gabion Cage’), which is made with a mesh structure that is filled with rocks, stone, concrete or other, non-degradable material. (*It is used for landscaping, retaining walls (for erosion control and dams) and sea defence.)

Bioremediation is a treatment technique that utilises organisms (such as microbes and bacteria) to remove environmental pollutants from air, soil, water and industrial effluents, among others – through the biological degradation of pollutants into non-toxic substances.

Evapotranspiration is the total water loss to the atmosphere from the Earth’s surface. (*It combines evaporation (movement of water from soil, canopies and water bodies to the air) and transpiration (movement of water from the root systems, through vegetation and their leaves, and into the air). Usually expressed in units of depth, it can be affected by factors, including heat, humidity, air speed (for evaporation), plant and soil type, as well as water content and cultivation practices (for transpiration).)

A Rain Garden – also called a ‘Bioretention Facility’ – is a garden of native shrubs, perennials and flowers that are planted in a small land depression, which acts as an infiltration point, temporarily holding (during the rainfall event) and soaking in rain/stormwater runoff from roofs, driveways, patios and/or streets.

A Bioswale is a shallow, landscaped depression – a ‘channel’ – that captures, treats and infiltrates stormwater runoff as it moves downstream. (*It has a top layer of enhanced soil with plants, and a porous, bottom layer of typically gravel which is packed in a geotextile, to prevent any cloggage by sludge or roots).

A Filter Drain – also known as a ‘French Drain’ – is a shallow, linear trench – lined with a geotextile and filled with gravel or stone – which is used to collect, filter and soak runoff water into the surrounding soil.

A ‘Sustainable Urban Drainage System (SuDS)’ is a water management and a drainage system that by mimicking natural water processes, collects, stores, filters rain-/stormwater runoff (close to where the rain falls) and conveys it by slowly releasing it back into the environment. (*Some of the most common examples of SuDSs include permeable pavement, bioswales, wetlands, green roofs and detention basins.)

A Filter Strip – also referred to as a ‘Buffer Strip’ – is a gently sloping, vegetated strip of land, which slowly conveys and infiltrates stormwater. (*It is commonly used to reduce contamination of stormwater runoff from roads, highways, small car parks and other pervious surfaces. It is also used in agriculture, to control ‘nonpoint source’ pollution.)

A Filter Trench is a shallow excavation of land – filled with rubble or stone – that creates a temporary, subsurface storage for stormwater runoff. (*It can be used to filter and convey stormwater downstream sustainable urban drainage system components) (Susdrain, 2022).

A Soakaway is a hole/pit – dug into the ground and filled with coarse stone and rubble (or plastic crates) – which receives surface water from a drainage pipe, and enables it to slowly infiltrate in the soil, reducing flood risk and improving the ground’s stability.

A Detention Basin – also referred to as a ‘Dry Pond’ or a ‘Holding Pond’ – is an open, excavated, often flat, vegetated land that is commonly installed adjacent to rivers, streams, lakes or bays to attenuate the peak flow from a rainfall event, by storing water for a short period of time. (*Primarily used as a mitigation measure for flooding, it can also protect against downstream erosion.)

An Infiltration Basin – also known as a ‘Recharge Basin’ – is a vegetated, shallow depression of land, designed to store stormwater runoff until it gradually infiltrates through the soil of the basin floor. (*The basin is generally dry, except for during heavy rainfall periods. The performance of the basin largely depends on the soil’s permeability and the depth to the water table.)

‘Water-sensitive Urban Design (WSUD)’ is an approach to land planning and engineering that integrates the urban water cycle into the urban design, to minimise overall environmental degradation. (*It considers stormwater, groundwater and wastewater management, as well as water supply. Greywater recycling and reuse, rainwater harvesting, urban greening for stormwater filtration, water-efficient landscaping and localised wastewater treatment systems are some of the common WSUD techniques. WSUD practices include integration of bioretention systems, swales and basins, infiltration trenches, buffer strips, constructed wetlands, sand filters, permeable pavement, rainwater tanks and Aquifer Storage and Recovery (ASR), among others.).

Soil Tillage is the mechanical manipulation of soil to control for weeds and pests and to prepare for seeding. It includes digging, stirring and overturning the soil.

Mulching is covering soil with a thick (usually organic) material to conserve its moisture, improve its health and fertility and to reduce weed growth. (*A mulch can be temporary (e.g. bark chips) or permanent (e.g. plastic sheeting).)

‘Blue Water’ is the fresh surface and groundwater water that is found in lakes, rivers and aquifers. (*Its availability varies within a year and also from year to year. ‘Recharged’ by precipitation, ‘blue water’ can be used for drinking and agricultural irrigation where it is abstracted to maintain transpiration.)

A ‘10-year Rain Event’ – also known as a ‘10-year Storm Event’ – is a rain/storm event that is ‘capable of producing rainfall expected to be equaled or exceeded on the average of once in 10 years’ (Law Insider, 2022).

‘Groundwater Table’ – also known as the ‘Water Table’ – is the upper surface of zone of saturation where ground’s pores and fractures are saturated with water.

An Agrochemical – also known as ‘Agrichemical’ – is a chemical product (e.g. pesticides, fertilisers, animal husbandry chemicals) used in agriculture.

‘Eutrophication’ is the process by which water in aquatic or terrestrial environment becomes progressively enriched with nutrients and minerals (particularly with nitrogen and phosphorus) which leads to the increased growth of algae, changes in the organisms’ balance and water quality degradation.

A Biodegradable product is one that is capable of being broken down and decomposed by bacteria or other living organisms, in turn, avoiding pollution.

Riparian Ecosystems are ecosystems that occur along watercourses and water bodies, and they include riverbanks, floodplains and wetlands.

A Levee – also known as a ‘Dyke’ or an ‘Embankment’ or a ‘Floodbank’ – is a naturally occurring ridge, or an artificially constructed wall structure (typically earthen), which usually runs parallel to a river’s course in its floodplain or along low-lying coastlines, to protect against flooding.

Effluent is a liquid waste or sewage that is produced and discharged by an industrial or commercial premises (e.g. industrial outfall, sewage treatment plant), outflowing into a natural water body (e.g. a river or sea).

‘Virtual / Embedded Water’ – also known as ‘Indirect Water’ – is the water that is ‘hidden’ in the processes, services and products. (*A concept coined by geographer, John Anthony Allan in 1993, ‘virtual water’ represents the embedded water that is exchanged when goods and services are traded from one placed to another.)

‘Integrated Water Resource Management (IWRM)’ is ‘a process which promotes the co-ordinated development and management of water, land and related resources, in order to maximise the resultant economic and social welfare in an equitable manner without compromising the sustainability of vital ecosystems’ (GWP SAS, 2018).

Micro-irrigation is a type of irrigation system that uses low-pressure and -flow rate (compared to average sprinkler systems) to reduce the likelihood of overwatering the planted area. (*It is commonly used in agriculture (for row crops), orchards, and vineyards, as well as in horticulture (wholesale nurseries), landscapes and gardens. Directly delivering water to where it is needed the most (i.e. the plants’ root zone), this type of irrigation minimises water wastage, which may occur due to evaporation.)

Drip Irrigation – also known as ‘Trickle Irrigation’ – is a type of micro-irrigation system that allows water to drip to the plants’ roots at very low rates (at 2–20 litres/hour) (FAO, 2022). (*Distributing water through a network of pipes, valves, tubing and emitters, this system can drip water either from above the soil or buried below the surface.)

Xeriscaping is the practice of landscaping or gardening with drought-tolerant and slow-growing plants, adaptable to local climate and environment, to conserve water from irrigation and reduce yard trimming.

Hydrozoning is the practice of clustering together plants that have similar water requirements, to conserve water from irrigation.

In the context of climate change, ‘maladaptation’ is a process ‘whereby people become even more likely to be negatively affected by climate change’ as a result of a certain (adaptation) action/s taken (Schipper, 2020).

A ‘Resilience Corridor’ is a planning strategy that promotes the development of the same-named ‘arteries’ (especially in coastal cities) by utilising existing, dry and raised (i.e. located on higher grounds) roads (in especially coastal cities) as ‘an infrastructure link to tie the surrounding, vulnerable communities along the coast, to upland territories’ (UCONN, 2019). (*As a form of retreat, a ‘resilience corridor’ also offers coastal communities an emergency egress opportunity in times of flooding.)

A Sand Engine/Motor is a type of beach nourishment where natural process of wind, waves and tides redistribute a large amount of sand/sediment (that is added to the coast in bulk) along the coast, over many years, avoiding the need for continuous beach nourishment. (*As a buffer against sea level rise, it protects against coastal flooding, mitigates the impacts of storm surges and protects the coastline.)

A Tidal Wetland is a flat, vegetated area of land, subject to regular flooding by tides. (*Often found along seacoasts (within reach of ocean’s tides), it includes salt marshes (near river mouths, in bays, on coastal plains and behind barrier islands), mangrove swamps (which replace salt marshes in subtropical and tropical regions of the world) and tidal freshwater marshes (along some tidal rivers).)

A Salt Meadow – also known as a ‘Ocean Meadow’ or a ‘Seagrass Meadow’ – is an underwater ecosystem (formed by seagrasses) which are flowering, marine plants that are found in shallow, coastal waters. (*It provides food and habitats for a diversity of marine life, including invertebrates (e.g. shrimps, crabs) and offers refuge for endangered species (e.g. seahorses, turtles).)

A Salt Panne (and pool) is a water-retaining, shallow depression found within salt and brackish marshes, where the marsh is poorly drained. (*Occurring both in low (which is usually devoid of vegetation) and high (which has moderate amount of vegetation) salt marshes, a panne’s increased salinity dictates the type of flora and fauna is able to grow within it.)

An is a modular, precast concrete armour unit used for the construction of coastal and marine defences, including dykes and breakwaters.

A Tide Pool – also known as a ‘Rock Pool’ – is an isolated, shallow pool of seawater which is found in the ocean’s intertidal zone. (*It provides habitats for snails, mussels, anemones, urchins, seaweed, small fish and crustaceans, among others.)

A Blowout Dune is a sandy depression in a dune ecosystem which is caused by the removal of sediments by wind. (*Commonly found on arid margins and in coastal settings, it can also be formed by vegetation loss, which leaves the soil bare, allowing it to be easily blown away by the wind.)

Peatlands are terrestrial wetland ecosystems, characterised by waterlogged soils made of dead and decaying plants, called ‘peat’ (which is also known as ‘turf’). (*They store ‘vast amounts of carbon – twice as much carbon as all the world’s forests’ (UNEP, 2019).)

‘Water Gap’ is a disparity found between water supply and demand, indicating the growing ‘water scarcity’.

Chapter 7: Ecology and Biodiversity

A ‘Carbon Sink’ is a natural or an artificial reservoir/medium that indefinitely absorbs and stores carbon dioxide from the atmosphere, using biological and physical mechanisms and processes. (*Oceans (capturing ‘blue carbon’) and vegetation (where the soil stores carbon) are the largest, natural carbon sinks on the planet. Bio-based building materials (e.g. timber, hemp, mycelium), and ‘Carbon Capture and Storage’ technologies are some of the ‘artificial’ methods used for sequestering carbon.)

‘Net Biodiversity Loss’ is the decline or disappearance of biological diversity (i.e. the variety of all living things on the planet). (*It describes the decline of different levels of biological organisation, genetic variability, number and variety of species and the biological communities within a defined geographic area.)

Rewilding is a progressive approach to conservation and ecological restoration, by enabling natural processes to shape land and sea, consequently repairing damaged ecosystems and restoring degraded landscapes.

‘Urban Fabrics’ is a planning theory that demonstrates ‘how the transportation systems create city form and function’. (*Developed by Newman and Kenworthy (2015), it aims to enable planners to create strategies for managing different ‘fabrics’ in three main city types: walking city, automobile city and transit city (Thomson and Newman, 2018). Based on their transport infrastructure priorities, each fabric (with their physical elements and environment) has a specific set of spatial relationships, typology of buildings and land-use patterns.)

Ecosystem Services are direct and indirect contributions and benefits the ecosystems – known as the ‘natural capital’ – provide for people. (*Examples include purification of water and air, regulation of erosion and natural hazards, decomposition of waste, pollination of plants, provision of food, energy, and biogenic materials, as well as non-material benefits, such as recreational, cultural and educational functions, among others.)

An Urban Food System is a system for producing food in urban areas, and it relies on the technical, social and economic design and development of urban environments in the distribution of food, land, water and energy production (Wageningen University & Research, 2022). (*It can promote food security, increase access to fresh produce, minimise food waste, transport-related carbon emissions (due to food source being close to the point of consumption) and pollution, as well as enhance community health, among many other benefits.)

Biodiversity Value is the social, environmental and economic value biodiversity brings to people, including recreational, cultural, spiritual, health and physical protection against natural disasters, among others.

‘Biodiversity [Loss/Damage] Mitigation Hierarchy’ is a tool widely used as an approach for identifying strategies that limit a development’s negative impacts on biodiversity. (*It commonly involves a series of iterative and sequential steps (to be followed throughout a project’s life cycle), prioritising avoidance, followed by minimisation, restoration and offsets, as the last resort.)

‘Biodiversity Action Plan (BAP)’ is an internationally recognised programme that addresses threatened species and habitats. (*Developed following the 1992 Conventional on Biological Diversity (CBD), it is designed to protect and restore biological systems.)

‘The International Union for Conservation of Nature (IUCN) Red Lists of Threatened Species’ – also known as the ‘IUCN Red List’ – is the world’s most comprehensive inventory, providing information on the global extinction risk status of various biological species (IUCN, 2022). (*Established in 1964, it provides data which is used to measure progress towards ‘Aichi Biodiversity Targets’ (adopted by governments at COP10) – specifically the Target 12, which aims to prevent extinction of known, threatened species and to improve, as well as sustain their conservation status by 2020.)

‘EU Biodiversity Strategy for 2030’ is a comprehensive, long-term plan – developed and launched by the European Union (EU) in 2020 – to protect nature and reverse ecosystems’ degradation. (*As a core part of the ‘European Green Deal’, it requires the restoration of degraded ecosystems, especially those with the highest potential to absorb and store carbon from the atmosphere) (European Commission, Environment, 2022).

‘Local Nature Partnerships (LNPs)’ are partnerships of a wide range of local businesses, organisations and people that come together with the aim to help improve their local, natural environment.

‘Urban Greening Factor (UGF)’ is a planning tool that is used to evaluate both the quality and the quantity of the proposed urban greening. (*Adapted from the ‘Green Space Factor (GSF)’ – originally developed in Germany, as a tool for landscape planning – UGF is calculated using a rating system where each surface type on a proposed development, is given a rating/score that ranges between the lowest, 0 and the highest, 1. As an example, The London Plan 2021 indicates ‘UGF scores of 0.4 for predominantly residential and 0.3 for predominantly commercial developments’ as a minimum.)

‘Lawton Principles’ are a set of principles that promote ‘the creation of a healthy, ecological network, operating across the landscape as a whole, not in isolated reservoirs’ (Leicestershire County Council, 2020). (*Defined in 2010 by Sir John Lawton in his report to the UK Government, called ‘Making Space for Nature‘, the five principles include: core areas (with the highest wildlife value), corridors and stepping stones (that allow for movement and interaction), restoration areas (where species and habitats can be restored), buffers zones (which protect all these areas from the pressure of human influence) and sustainable use areas (that have greater human influence and resource use).)

‘Biodiversity Net Gain (BNG)’ is an approach to development and/or land management that is used to improve a site/land’s biodiversity value. (*It aims to leave the natural environment in a measurably better state than its original conditions. (*The UK Department for Environment, Food and Rural Affairs (Defra)’s ‘Biodiversity Metric’ underpins the UK’s Environment Act 2021’s minimum 10% biodiversity net gain requirement for all development sites.)

‘Habitat-Banking’ is trading in habitat or biodiversity ‘credits’ (which are generated by habitat creation, or enhancement, to offset residual biodiversity losses caused by a development) to compensate for unavoidable habitat destruction, through development (British Ecological Society, 2010).

‘Nature Climate Solutions (NCS)’ are actions that conserve, restore and improve land management, to increase carbon storage or avoid greenhouse gas emissions in landscapes and wetlands all around the world (The Nature Conservancy, 2022).

‘Natural Infrastructure (NI)’ is ‘a planned or managed, natural, or semi-natural system that is designed to provide a specific benefit’ (WBCSD, 2017). (*It may consist of a stand-alone natural ecosystem or a hybrid solution, which combines a natural system and a grey infrastructure.)

‘Phytotechnology’ is the application of plants to engineering problems.

Bio-based Materials – also referred to as ‘Biomaterials’ – are materials made from substances that are derived from living (or once-living) organisms. (*Often biodegradable, they include bioplastics, engineered wood and cellulose fibres, among others.)

Mycelium is a web-like structure of a fungus that is prevalent in forests, fields and heavily wooded areas. (*With is multicellular structure, it can grow into macro-size ‘fruits’, which we commonly recognise as mushrooms. Mycelium can be used to create building materials that are renewable, strong and light. Due to its inherent properties, it can be recycled and regrown for many times.)

Biocrete is a concrete-like material, created by a mixture of natural fibre and hydrated lime or calcium hydroxide. (*It is generally not intended as a load-bearing material. To increase its (load bearing) capacity, sand can be added to biocrete – at the expense of its thermal insulating properties. Seen as a disadvantage, biocrete can take up to five times longer than a (traditional) concrete to cure (Lim, 2013).)

A Bio-based Building Component is a building component that is in full or in predominance made of bio-based materials.

A Bioreactor is a manufactured, vessel-like device or a system that supports a biologically active environment. (*Maintaining an uninterrupted balance in the biochemical processes, it offers a uniform background for microorganisms to grow and turn into a ‘product’.)

A Regenerative Process is a renewal process where damaged or missing elements are restored to their full function.

Bio-cementation is an ecological process and ‘a technique that uses microorganisms to produce calcium carbonate for construction purpose’, as a binding agent (Iqbal et al., 2021).

Biomanufacturing is a type of manufacturing or biotechnology that relies on biological processes – using enzymes and microorganisms – to manufacture a variety of products for different sectors, including pharmaceutical (e.g. vaccines, antibacterial drugs, cell therapies), consumers products (e.g. detergents, textiles, biofuels), food and beverage (e.g. fermentation) and industrial and environmental (e.g. chemicals, bio-cementation).

A Bioplastic is a plastic material that is produced from a natural or a renewable source, such as vegetable oils, sugarcane, straw, woodchips, corn starch, recycled food waste and yeast, among others. (*It is commonly used for packaging, cutlery, bowls and straws, and it can either be biodegradable (e.g. thermoplastic starch, polylactic acid) or non-biodegradable (e.g. bio-based polyethylene, bio-polycarbonate).)

Biofuel is a fuel that is derived from ‘biomass’ (i.e. plant, or algae material or animal waste). (*Considered as a renewable energy source, it is typically used for transportation purposes. The most common examples of biofuel include ethanol (either used as 100% ethanol fuel, or blended with gasoline to produce ‘gasohol’, or used as a gasoline additive) and biodiesel (used in diesel engines and usually blended with petroleum diesel fuels in various percentages). Other biofuels include methane gas, biogas, methanol, butanol and dimethyl ether (Britannica, 2022).).

Suburbanisation – also known as ‘Dispersed Land Development’ – is a shift of population from central urban areas into rural urban fringes (i.e. suburbs), resulting in a suburban sprawl of low-density, peripheral, urban growth.

‘Habitat Fragmentation’ – also known as the ‘Species Fragmentation’ – is a process by which large and continuous habitats are divided into smaller, isolated patches of habitats, causing population fragmentation and ecosystem decay. (*‘Habitat Fragmentation’ can occur due to natural processes (e.g. volcano eruption, fires and climate change) or human activities (e.g. urbanisation, logging and cutting down forests and land conversion).)

An ‘Edge Effect’ is an ecological alteration in a natural population, or a community structure that occurs at the boundary of two or more habitats. (*Linked with the development of sudden, artificial edges, it breaks down the continuity of adjacent habitats, leading to higher probabilities of local species extinction. Examples include when an agricultural field meets a forest or when a road cuts through a forest.)

An ‘Urban Teleconnection’ is a ‘processed-based conceptualisation that intertwines land use and urbanisation by linking places through their processes’ (Seto et al., 2012). (*It can extend from short distances (e.g. between a central urban area and a peri-urban area) to longer distances (e.g. between places across nations or continents). The unexpected linkages that occur between the urban and the hinterland can be a result of urban–rural income inequalities (which can cause urban migration), extraction/sourcing of raw materials for construction and land use changes due to migration, among others (Güneralp et. al, 2013).)

‘Inclusionary Zoning’ – also known as ‘Inclusionary Housing’ – are municipal and county planning ordinances / local policies that mandate or provide incentives for including affordable housing units (at below market rate) in new developments. (*First developed in the USA in the early 1970s, ‘Inclusionary Zoning’ is used as a planning tool to encourage mixed-income neighbourhoods. The proportion of the affordable housing units a developer must build (according to this Zoning requirements) usually depends on the size of the project).

Density Factor is a zoning term used to describe the maximum number of dwelling units that are permitted per acre on a development. (*It is calculated according to the town’s land use plan and relevant neighbourhood plans, as well as the town’s ordinances and applicable zoning regulations.)

‘Tallness Factor’ is a metric (developed by Pomponi et al., 2021) that is used to describe the average height of an urban area, with the aim to specifically ‘decouple density from “tallness” in analysing the life cycle greenhouse gas emissions of cities’.

Economy of Scale is a term used to describe the greater benefit an organisation or an intervention can bring from the increased size of its operation.

‘Farm to Fork’ is a strategy that is used to reduce environmental impact of primary food production, and provide a healthy food supply, while also ensuring fair economic returns to the producers (i.e. farmers).

An ‘Agrivoltaic’ – also known as an ‘Agrophotovoltaic’ – is the simultaneous use of land for both agriculture and solar energy generation.

Agroecology is the application of ecological processes, concepts and principles to agricultural food production. (*Recognised both as a climate change mitigation and adaptation strategy, it ‘centres on food production that makes the best use of nature’s goods and services, while not damaging these resources’ (Agroecology Fund, 2022). ‘Agroforestry’ – which combines agriculture and trees – is a well-recognised example of agroecology.)

‘Bioregional Planning (BP)’ is planning that aims to preserve the integrity of a bioregion through informing ‘land-use planning and decision-making, by a range of sectors whose policies and decisions impact on biodiversity’ (Biodiversity Advisor, 2022). (*It includes a map of critical biodiversity areas, together with land-use guidelines for preventing loss or degradation to natural habitats in critical biodiversity areas.)

‘Biophilic Urbanism (BU)’ is a planning approach that aims to systematically integrate nature into the urban fabric. (*Focusing on the ecological systems and human activities (that are delivered by biophilic interventions), it aims to improve connections between urban dwellers and nature, and derive benefits from natural services, as well as functions (Cabanek et al., 2020).)

Epistemology is ‘the philosophical study of the nature, origin, and limits of human knowledge’ (Britannica, 2022).

‘Climate Dynamics’ is the field that studies the processes, which control the climate system and its evolution (Penn State University, 2020).

‘Garden City’ was an urban planning movement that promoted satellite communities around a central city, separated by greenbelts. (*Devised in the 20th century by town planner, Ebenezer Howard, it aimed at capturing the primary benefits of the city and the countryside, while avoiding the disadvantages they both presented.)

‘Regenerative Design’ is a process that adopts a whole systems’ approach to design with the aim to restore, renew or revitalise processes’ own sources of energy and materials. (*It uses whole systems thinking to create resilient and equitable systems, which integrate the society’s needs with the integrity of nature (Wikipedia, 2022).)

Urban Regeneration – sometimes also referred to ‘Urban Renewal’ – is an approach to city planning to ameliorate the appearance, infrastructure and economy of a ‘decaying’ (i.e. obsolete or blighted) city area by improving its physical and environmental aspects.

Environmental Ethics is a branch of philosophy that studies the moral relationship of human beings to the environment.

Agroecosystems are cultivated ecosystems where communities of plants and animals interact with their physically and chemically modified environment by people, to produce food, fibre, fuel and other products for consumption and processing. (*They are composed of grassland and cropland) (Biodiversity Information System for Europe, 2022).

‘Land Sparing’ – also known as ‘Land Separation’ – is an approach where urban areas are separated from the high-yielding, intensified agriculture and natural habitats (on a small land footprint), to promote ecosystem services in agricultural settings – allowing for environmentally friendly food production. (*Examples include woodlands, wetlands, natural grasslands and meadows on arable lands.)

‘Land Sharing’ is an approach where low-yielding, wildlife-friendly farming systems (on a larger land footprint, with biodiversity-rich species throughout) enable the conservation of crucial species that are incompatible with agriculture, by segregating biodiversity conservation from production.

A greenfield site is an undeveloped land (such as a grassland, woodland or an agricultural land) that is typically found outside of urban areas.

Hydroponics is the process of growing plants – usually crops – without using soil. (*In the hydroponic system, terrestrial or aquatic plants are fed on mineral nutrient salts that are dissolved in water. Commonly grown in greenhouses or contained environments, plants that can be grown using a hydroponic system include tomatoes, peppers, lettuces, strawberries and cucumbers, among others.)

Aquaponics is the process of producing food by combining aquaculture (i.e. farming fish) and hydroponics (i.e. growing plants in a nutrient solution). (*In the aquaponic system, plants (commonly leafy lettuce, tomatoes, basil, cauliflower, etc.) are grown in a grow bed on top of a fish tank, which contains fish. As plants absorb the nitrates (from the fish waste that has gone through a biofilter) and other nutrients, they grow. In this process, plants clean and filter the water, which gets recirculated back to the fish tank, leading to the next cycle’s start. Aquaponic systems can either use freshwater or contain salt or brackish water, and their unit size can vary from small, indoor units to larger commercial ones.)

Aeroponics is the process of growing plants in an air or mist environment, without using soil or an aggregate medium. (*In the aeroponic system, plants grow in a soilless medium, called rockwool. Examples of plants that can be grown using this system include microgreens, leafy greens, fruiting and rooting crops, among others.)

‘Seven-layer System’ is a system, emerged from the ‘Forest Garden’ (an agroforestry) concept that was pioneered by horticulturist Robert Hart, based on his observations that natural forests can be divided into distinct layers. (*The system is comprised of seven layers: ‘canopy layer’ (consisting of mature fruit trees), ‘low-tree layer’ (consisting of smaller nut and fruit trees), ‘shrub layer’ (consisting of fruit bushes), ‘herbaceous layer’ (consisting of perennial vegetables and herbs), ‘rhizosphere’ (consisting of plants grown for their roots and tubers), ‘ground cover layer’ (consisting of edible plants that are spread horizontally) and ‘vertical layer’ (consisting of vines and climbers).)

A Regenerative Agricultural Practice is a farming and grazing technique that by increasing soil fertility, water retention and cleanliness, soil carbon sequestration and biodiversity, it improves the overall health of the local ecosystem. (*It includes practices such as employing crop rotation, using greater crop variation and shifting from synthetic to organic fertilisers.)

Permaculture is ‘an approach to land management and settlement design that adopts arrangements observed in flourishing natural ecosystems’. (*It uses design processes, based on ‘whole-systems thinking’ and considers strategies that promote ‘circular’ approaches for all materials and resources) (Wikipedia, 2022).

Aquaculture – also known as ‘Aquafarming’ – is the farming of aquatic organisms, including fish, molluscs, crustaceans, algae, aquatic plants and other organisms. (*It can take place both in controlled marine and freshwater environments. ‘Mariculture’ (e.g. breeding molluscs or prawns or other organisms, using seawater), ‘fish farming’ (e.g. selective breeding of fish in fresh- or seawater), ‘algaculture’ (e.g. cultivating algae) are some examples.)

‘Bio-based Economy’ – also referred to as ‘Bioeconomy’ – is an economy that draws its resources from the living nature (e.g. ‘biomass’), and uses ‘biotechnology’ to produce of goods, services and energy. (*It is important to note that ‘bio-based economy’ takes into consideration the production of non-food goods, while ‘bioeconomy’ covers both bio-based economy and the production, and use of food and feed (Wikipedia, 2022).)

An Espalier is a decorative fruit tree, woody plant or a shrub that has been ‘trained’ to grow flat against a wall, fence or trellis.

Chapter 8: Connectivity and Transport

Previously Developed Land is land that is/was occupied by a permanent structure. (*Land that has been occupied by agricultural or forestry buildings, or that has been developed for mineral extraction or waste disposal purposes, or that has been built-up as gardens, parks and/or that only had temporary structures, are not considered as ‘previously developed land’. (UK Planning Portal, 2021).)

Reclaimed Land is newly created land from the sea, or other water bodies. (*This could be land that is impaired by a natural phenomenon, such as a tsunami, or earthquake. It could also be a submerged wetland that is reclaimed for agricultural use. It is important to note that reclamation of land on coastal areas have significant, negative environmental impacts to the local, natural ecosystem.)

‘15-Minute City’ is an urban concept, describing a city vision where the effective planning of infrastructure and urban development would enable city residents to meet all their needs by walking and/or cycling at a short (15-minute) distance from their homes. (*The concept – also known as ‘Complete Neighbourhoods’ – was originally inspired by French-Colombian scientist, Carlos Moreno.)

‘Reblocking’ of an informal settlement is realignment of structures to enable basic services to be delivered, while also likely resulting in more usable space and reduced fire risk.

A Metropolis is a large city with more than 300,000 inhabitants. (*It is typically defined as the capital city of a country.)

A Polycentric City is a city that has one or more employment sub-centres outside of the central business district, to achieve a balanced metropolitan system.

A Monocentric City is a city that has a single, ‘Central Business District (CBD)’.

A Regenerative City is a city that enhances and restores natural systems, whose resources the city draws from hinterland, for its sustenance.

A ‘Sprint Rapid Transit Vehicle’ is a transportation system that uses tram-style vehicles, which run on road-going wheels, rather than tracks, to provide fast and reliable journeys (West Midlands Combined Authority, 2018).

‘Last-mile’ is a terminology used to describe the last part of a journey where people and goods are moved from a transportation hub to their final destination.

‘Artificial Intelligence (AI)’ is a field that combines computer science and robust datasets, to facilitate decision-making and problem-solving. (*It is the simulation of human intelligence in machines, which are programmed to think like humans and mimic their actions.)

An ‘Autonomous Vehicle’ – also known as a ‘self-driving’, or ‘driverless car’ – is a car that incorporates vehicular automation (with a variety of sensors), enabling it to sense its surroundings, and move with little or no human intervention.

‘Demand-Responsive Transport (DRT)’ – also known as ‘Demand-Responsive Transit’ – is a form of shared, quasi-public or private, flexible transport, used by groups of people, who can arrange (via a mobile app, or telephone) a pick-up or drop-off from/to their desired location and time. (*Including taxis, buses, minibuses and other vehicles, these vehicles change their routes (based on the particular transport demand), rather than following a fixed route.)

A Mobility Hub is a place where spaces for cars, bikes, taxi hire or drop-off, parcel pick-up stations, and interchange between rail, bus or local shuttle are provided – ideally adjacent to public realm. (*A mobility hub should be visible from adjacent streets, and have generous, public space with wide, pedestrian paths, travel information display boards, covered waiting areas and convenience stalls for snacks (Building for a New Urban Mobility, Centre for London, 2020).)

‘Advanced Air Mobility (AAM)’ is an airborne technology that uses electrical take-off and landing (eVTOL) aircraft that enables the transportation of people and goods, flying around both in rural and urban environments, and serving especially spaces that are not easily serviced by land/surface transportation or existing aviation modes. (*It is envisioned that such an aircraft will be powered by hybrid electric systems, batteries or hydrogen fuel cells (National Business Aviation Association, 2022).)

A ‘Light Commercial Vehicle (LCV)’ is a motor vehicle (with typically four wheels) that transports goods and specialised equipment. (*Such a vehicle could be a utility vehicle, a heavy lorry or a minivan.)

An ‘Autonomous Air Vehicle (AAV)’ is an unmanned, electric vehicle that transports goods and people.