Demographics is one of four scans that forms part of the Population Change theme for RIBA Horizons 2034.
Over the next ten years, demographic changes will impact the size and composition of national and global populations, influencing where and with whom people will live and the type of homes, communities and cities that architects will be called upon to design.
Slowing population growth
Following a century of unprecedented rapid growth in the world’s population during which the size of the global population has quadrupled from two billion in 1930 to eight billion in 2022, the pace of population growth is now slowing down.
According to the latest data from the United Nations Population Division, in 2020 the global population growth rate fell below 1% per year for the first time since 1950. [1] Today, many countries have low or even negative rates of ‘natural’ population growth (measured as the difference between the birth rate and the death rate), reflecting the fact that people are choosing to have fewer children.
At the same time, advances in medical technologies, alongside improvements in sanitation and nutrition, mean that life expectancy has been rising. In 1950, the average life expectancy at birth for the world as a whole was just 46.5 years; by 2020 this had reached 72 years. Over the next decade, it is projected to continue to improve by another three years, reaching 75.3 in 2035 – a rate of improvement equivalent to seven hours a day.
An ageing population
With more people living longer and fewer births, the global population is also ageing. One measure of a population’s ‘age’ is provided by its median age (the age where half the population is aged below this level and half above). In 1950, the median age of the global population was just 22.2 years. By 2020, it had risen to 29.7 years and by 2035 it is predicted to increase to 33.1 years. [2]
There are however significant differences by region. In 2022, the ‘oldest’ country in the world by this measure was Monaco at 54.5 years, followed by Japan (48.4 years) and Italy (47.3), with the UK at 39.6 years. The ‘youngest’ five countries are all found in sub-Saharan Africa, with the median age in Niger being just 14.5 years and in Mali, 15.1 years.
Another useful measure of population ageing is provided by the share of the population aged over 65 years. In 2023, Monaco was the country with the highest percentage (36%) of the total population over the age of 65 years. (This is not surprising given their population’s median age.) Japan had the second highest (29%), while Portugal and Bulgaria followed in joint-third place (24 %). [3]
Currently, 19% of the UK’s population is aged 65 years and over. According to the latest population projections published by the Office for National Statistics (ONS) in January 2024, by 2040 the size of the UK population aged 65 years and over is projected to increase from 13 million (19% of the total population) to 16.9 million (23% of the total population). [4]
These demographic changes have important implications for the built environment and how architects plan for and design homes, schools, workplaces, hospitals, shops, leisure facilities and many other building types.
For example, falling birth rates in many countries mean that over the next decade, fewer places in schools will be needed. In England and Wales in 2022 there were just 605,479 live births, a 17% decrease from 729,674 in 2012. [5] As these smaller cohorts of babies and children move through early years into reception and then into primary school, they will shape the demand for classroom spaces.
The UK is far from alone in experiencing a reduction in birth rates. In 2023, the fertility rate in Taiwan was estimated to be 1.09 children per woman, making it the lowest in the world, closely followed by South Korea at 1.11 and Singapore at 1.17, with Italy (1.24) and Spain (1.29) also in the lowest 10 countries in the world. [6]
Changing living arrangements
The lower number of births in part reflects trends towards delayed marriage and childbirth, which in turn are echoed in more young adults either living alone or sharing in multiple-person households. According to a recent report by Euromonitor International, child-free households are set to become the main household type by 2040, transforming consumer demand. [7]
Property developments providing accommodation for young adults with shared communal facilities have been on the rise over the last decade, extending the concept of ‘student living’ beyond the boundaries of higher education. A good example is The Collective in Canary Wharf, which offers individual studio apartments with shared living and co-working spaces along with organised events, libraries, restaurants, and cinema rooms.
At the other end of the life course, co-housing is also gaining in popularity. This is exemplified by the Older Women’s Co-Housing group, which recently established a community in flats in Barnet, north London, with residents aged from 58 to 94 years.
Rethinking homes for intergenerational living
Across the globe, many individuals live in households with multiple generations of related adults. Indeed, in some parts of the world, especially parts of Asia, this remains the predominant form of living. [8]
In the UK, the past decade has witnessed a rise in multi-generational living as more young adults are returning to the parental home and more frail older adults are choosing to live with their adult children. This reflects the rising costs of both housing for young adults and social care needs for frail elders.
Analysis of the UK Household Longitudinal Survey, Understanding Society, suggests that nearly 7% of UK households are multi-generational, which is equivalent to roughly 1.8 million households. [9]
More family members living together for longer is likely to require a rethink in how homes are designed. Existing spaces (including lofts and basements) might need to be remodelled and extended into gardens. Opportunities for flexibly ‘expanding’ or ‘shrinking’ living spaces and changing the way they are used will become more important considerations.
Innovations such as movable walls and fold-away furniture make it possible to design spaces that can easily change uses according to the needs of family life across generations.
Examples include a room that functions as a home office – an important issue with the rise of working from home – during the day that converts into a bedroom at night, or a large living room capable of being subdivided into separate spaces to meet family members’ differing and possibly clashing needs.
Meeting the rising demand for solo living
The demand for innovative design thinking is not restricted to the growth in multi-person households and multi-generational living. It is also required to meet the global growth in single-person households which, fuelled by rising divorce rates and, more significantly, a rapidly ageing population, is outpacing other kinds of housing by far.
Data from national censuses and large cross-country surveys indicate that single-person households are becoming increasingly common across the world, albeit with large differences between countries – from more than 40% in northern European countries to 1% in Pakistan. [10]
According to ONS, in 2022, 8.3 million people were living alone in the UK, representing 30% of all households. Over half (51%) of the people in these households were aged 65 and over, and more than one in five men and one in three women aged 75 years or over were living alone. [11]
Innovating flexible ‘lifetime’ homes
Harnessing the power of innovation to help meet the needs of an ageing society was recognised by the UK government in its recent industrial strategy as one of the four ‘grand challenges’ facing the country. [12]
Key to meeting this need will be to enable people to stay put in their homes and remain in their communities for longer by ensuring that their homes can adapt as they age, whether living with a partner, with wider family or alone. This means that all new dwellings should be designed with the life course of their occupants in mind.
Architects are already producing creative solutions with adaptable interiors, using many design tactics. These include:
- making it possible for bedrooms to be relocated to the ground floor
- ensuring that all corridors and doors are wide enough for both child buggies and electric wheelchairs
- installing wet rooms and voice-controlled or remote-activated services for heating and lighting as standard
Smart house digital technologies, robotics and artificial intelligence, combined with life-course-sensitive design will facilitate even more older people to live longer in their own homes. Given changing demographics, over the next decade, such design innovations are likely to move from being the exception to becoming mainstream practice.
Recent research has also highlighted the urgent need to provide more housing alternatives for older people, including alternative assisted living and transitional environments for individuals who are cognitively challenged and physically frail. [13]
Such residential care environments need to be easy to navigate spatially with appropriate wayfinding and, to promote good sleeping patterns, should minimise residents’ exposure to environmental stressors such as unwanted artificial light. The therapeutic benefits of having access to safe green spaces such as ‘wandering gardens’ are also being increasingly recognised.
In 2023, for example, the National Brain Appeal’s Rare Space Garden won a gold medal at the RHS Chelsea Flower Show, and the RHS website featured advice on creating dementia-friendly gardens. [14]
Promoting healthy ageing for all: designing age-friendly cities
The importance of designing age-friendly cities in promoting healthy ageing has recently been recognised by the World Health Organization. They have developed a framework of eight interconnected domains that can help to identify and address barriers to the wellbeing and participation of older people. [15]
Included in these domains are ‘housing’, ‘transportation’ and ‘outdoor spaces and buildings’, areas where architects and other design professionals can play a vital role in setting the agenda.
Going forward, all new buildings and their surrounding public realm should ideally be designed for diversity and inclusion, embracing all ages and capabilities, enabling people to stay active and remain connected to their communities.
On 14 December 2020, the United Nations General Assembly declared 2021–2030 the Decade of Healthy Ageing, with the objective of combatting ageism, social isolation and loneliness, and creating better places in which to grow, live, work, play, and age. [16]
To achieve these goals, built environment professionals will all need to rise to the challenge.
Author biography
Maria Evandrou is Professor of Gerontology and Director of the Centre for Research on Ageing at the University of Southampton. She is also co-director of the ESRC Centre for Population Change and the Connecting Generations research partnership.
Her research interests include inequalities in later life, health and social care in later life, informal care and paid employment in mid-life, and inter-generational flows of support. She has published over 200 journal articles, book chapters, books, reports and papers, and supervised 20 PhD students to completion. She has acted as an advisor to government departments in the UK and internationally, and also to NGOs.
RIBA Horizons 2034 sponsored by Autodesk
References
[1] United Nations, Department of Economic and Social Affairs, Population Division (2022). World Population Prospects 2022: Summary of Results
[2] United Nations, Department of Economic and Social Affairs, Population Division (n.d.). UN Population Division Data Portal: Interactive access to global demographic indicators
[3] Population Reference Bureau (2023). World Population Data Sheet 2023
[4] Office for National Statistics (2021). National population projections: 2021-based interim
[5] Office for National Statistics (2023). Births in England and Wales: 2022, Table 1
[6] Central Intelligence Agency (2023). The World Factbook, graph: Lowest total fertility rate (children per woman) (2023 est.)
[7] Euromonitor International - A. Jain (8 September 2023). Top Three Global Households Trends in 2023.
[8] A. Esteve and C. Liu (2014). Families in Asia: A Cross-National Comparison of Intergenerational Co-residence. Paper presented at the IUSSP Cyber Seminar on Family Demography: Advancing Knowledge about Intergenerational Relationships and Exchanges
[9] G. Burgess and K. Muir (2020). The Increase in Multigenerational Households in the UK: The Motivations for and Experiences of Multigenerational Living. In Housing, Theory and Society 37(3), 322–338
[10] Our World in Data - E. Ortiz-Ospina (2024). Loneliness and Social Connections
[11] Office of National Statistics (2023). Families and households in the UK: 2022
[12] Department for Business, Energy & Industrial Strategy (2021). The Grand Challenges (Policy paper withdrawn 1 March 2023)
[13] S. Verderber et al (2023). Residential Environments for Older Persons: A Comprehensive Literature Review (2005–2022). In Health Environments Research & Design Journal 16(3), 291–337
[14] Royal Horticultural Society - C. Olver (n.d.). Creating a dementia-friendly garden
[15] World Health Organization (n.d.). The WHO Age-friendly Cities Framework
[16] United Nations (n.d.). UN Decade of healthy ageing: The Platform
