RIBA UK Awards sustainability questions

RIBA's 2030 Climate Challenge sets a series of performance outcome targets for practices to aim towards, as explained further in the Sustainable Outcomes Guide. Each year, eligibility to enter RIBA Awards becomes more closely aligned with the objectives of the challenge, demonstrating the crucial role architecture must play in mitigating and adapting to the climate crisis, and as such the entry form includes mandatory requirements with respect to sustainability data. These key metrics are operational energy consumption, potable water use, and embodied carbon data.

In-use data for operational energy and potable water use derived from 12 months of occupancy has been a mandatory requirement for all stages of RIBA Awards since 2024.

Each year, the carbon data requested at different stages of the awards increases. By 2027, we expect all entrants in the RIBA UK Awards to provide full carbon reporting. Please see the diagram below demonstrating these incremental changes.

Read on to discover the questions you will be asked to fill in when you submit your project. Some information requested is mandatory, however if mandatory data is required but not applicable to your project, you can insert ‘0’ (zero) in the data field and provide an explanation in the relevant text box - e.g. a bridge will not be able to provide some mandatory data due to its typology.

Specification

1. Gross internal conditioned floor area (m²)

'Gross internal conditioned floor area' is the gross internal floor area that is conditioned (e.g. heated and/or cooled).

2. % Occupancy during 12-month period

The percentage occupancy, for this form, must relate to the energy data collection period.

3. Is the project new-build or refurbishment?

New build / Partial re-use or full refurbishment

4. Describe the extent of the work. (max. 300 words, optional)

Did the project make use of existing fabric or structure? Did the project team evaluate whether existing elements could be retained and upgraded instead of demolition and new build? Was a building demolished on site? Give details of its condition, include listed status if applicable.

5. Airtightness (m³/hr m² at 50Pa)

Mandatory for projects over 1000m² GIA

6. Provide any other supporting information relating to the building specification. (max. 200 words, optional)

Please include any sustainability certifications achieved.

7. Outline sustainability drivers, concepts, and specific environmental performance outcomes of the building. (max. 300 words)

How was sustainability considered during the architectural concept, form development, construction, and building end-use stages? Describe any performance analysis undertaken and the measured sustainability outcomes. Were there any special project objectives, challenges, or constraints? Was the design reviewed against the impacts of future climate change (e.g. future weather, flood risk, overheating risk)? Are there any innovations in sustainable construction? What are the key indoor and outdoor water use strategies? Please state how the project aligns with the RIBA 2030 Climate Challenge. Did the brief inform the sustainability strategy? What is the net-to-gross efficiency?

Operational Energy

8. Predicted energy use (kWh/m²/y) - a design prediction

This is the total annual predicted regulated and unregulated energy use (measured in kilowatt-hours per metre squared per year based on the gross internal area (GIA) of the building).

9. Actual energy use (kWh/m²/y) - the on-site reality

This is the total annual gross operational energy use (measured in kilowatt-hours per metre squared per year based on the gross internal area (GIA) of the building) taken from measured data. Figures should reflect gross energy use and therefore should include energy used on-site from any on-site renewables. The measurement should be taken from energy meter readings (or energy bills + PV meter) for the building over a year, so that both winter and summer seasons feature in the calculation.

A worked example can be found in this RIBA J article: How to calculate operational energy of a building.

10. Is gas used on site?

Yes / No

11. Gas usage (kWh/m²/yr) - the on-site reality

This is the actual annual gas usage.

12. On-site renewable energy generation (kWh/yr)

This is the total annual renewable energy generated on-site, excluding heat pumps.

13. Is your project connected to a district heat system?

14. If yes, please provide details (max. 200 words, optional)

What is the primary heating technology (e.g. gas boiler, gas combined heating and power, air/water/ground source heat pump)? If combined, please give an approximate split. At what temperature is the network delivering the heat? Is the heat upgraded in the building?

Water

15. Potable water use (l/person/day)

This is the total annual drinking water used on site, measured in litres per person per day (l/person/day) in domestic and non-domestic, and metres cubed per pupil per year (m3/pupil/yr) for schools, taken from measured data.

Carbon

Note: There are different amounts of mandatory project life cycle carbon data required at the various RIBA Award levels, as detailed below.

RIBA Awards: carbon project data is not mandatory for RIBA Awards 2025.
RIBA National Awards: upfront carbon and embodied carbon project data is mandatory at entry point.
RIBA Stirling Prize and Reinvention Award: upfront carbon, embodied carbon, and whole life carbon project data is mandatory at entry point.

The carbon accounting methodology should follow the current edition of the RICS Professional Standard on Whole Life Carbon Assessment for the Built Environment.

Diagram 1 shows the life cycle assessment modules to be considered for a WLCA. (Note that ‘biogenic carbon’ is shown separately from each of module’s A, B, C within ‘whole life carbon’. This is because when using, say, timber, the initial carbon benefits must be balanced by the end-of-life disposal carbon costs to get the true total carbon picture). Credit: RICS

16. Building design life (years)

17. Upfront carbon (KgCO₂eq/m²)

‘Upfront Carbon’ emissions are the greenhouse gas emissions associated with materials and construction processes up to practical completion (Modules A1-A5 of the RICS Whole Life Carbon Assessment for the Built Environment). Upfront carbon excludes the biogenic carbon sequestered in the installed products at practical completion.

This question is marked as optional for entrants, but is mandatory at entry point in order to be considered for the RIBA National Awards, RIBA Reinvention Award, and RIBA Stirling Prize 2025.

18. Embodied carbon (KgCO₂eq/m²)

The ‘Embodied Carbon’ emissions of an asset are the total greenhouse gas emissions and removals associated with materials and construction processes throughout the whole life cycle of an asset (Modules A1-A5, B1-B5, C1-C4 of the RICS Whole Life Carbon Assessment for the Built Environment).

This question is marked as optional for entrants, but is mandatory at entry point in order to be considered for the RIBA National Awards, RIBA Reinvention Award, and RIBA Stirling Prize 2025.

19. Whole life carbon (KgCO₂eq/m²)

‘Whole life carbon’ emissions are the sum total of all asset related greenhouse gas emissions and removals, both operational and embodied over the life cycle of an asset including its disposal (Modules: A1-A5; B1-B7 (plus B8 and B9 for Infrastructure only); C1-C4 of the RICS Whole Life Carbon Assessment for the Built Environment).

This question is marked as optional for entrants, but is mandatory at entry point in order to be considered for the RIBA Reinvention Award, and RIBA Stirling Prize 2025.

20. Confirm the basis for the carbon footprint breakdown provided above. Please expand and explain the method used for the calculation. (max. 300 words, optional)

Confirm which RIBA Stage calculations were undertaken at, and state assumed building life and assessment boundary (cradle to gate/cradle to practical completion/cradle to grave).

Confirm which life-cycle stages were included (i.e. Upfront carbon RICS Modules A1-A5; or Embodied Carbon RICS Modules A1-A5,B1-B5,C1-C4; Whole Life Carbon RICS Modules A1-A5,B1-B7,C1-C4).

If you have been unable to provide whole-building carbon figures, but have calculations for specific building elements, you can use this textbox to provide the data and specify how they have been reached.

21. Describe any strategies used in the building’s design to reduce embodied carbon. (max. 300 words)

Ecology/Biodiversity

22. Explain key the ecological strategies. (max. 300 words, optional)

How does the project enhance biodiversity, increase green infrastructure or create opportunities for productive growing spaces (e.g. local food production)? Were considerations made for biophilic design? What measures have been taken to mitigate any loss of Category A and B trees? Is the project situated on designated landscapes (e.g. greenfield land, Areas of Outstanding Natural Beauty, locally designated landscapes)? If so, what measures have been taken to mitigate the impact on the environment? How are any biodiversity net gain benefits safeguarded for future years on the site?

23. Biodiversity net gain (BNG) % (optional)

24. Any other supporting information relating to the sustainability data. (max. 200 words, optional)