Population & Urban Change in the UK
A Population in Flux
The UK population reached around 67 million in 2021 and is projected to pass 70 million before 2040. Population is changing in three main ways — birth rate has fallen, life expectancy has risen, and net migration is high. The combined effect is an older, larger and more unevenly distributed population than fifty years ago.
Why Birth Rates Have Fallen
In the 1960s, women in England and Wales had on average 2.9 children. By 2021 that figure was 1.6 — below the replacement level of 2.1. Economic factors push couples to delay or limit family size: rising childcare costs, expensive housing and longer time spent in education. Political factors include better access to contraception and women remaining in paid work. Social factors include changing expectations about careers and the choice to have smaller families.
An Ageing Population
An ageing population means that the proportion of people aged 65 and over is rising. By 2021 around 19% of the UK population was aged 65 or above; by 2050 it is forecast to reach 25%. This is the result of better healthcare, falling smoking rates and improved diets that have raised average life expectancy to about 81 years. This is often called the ‘greying’ of Britain.
UK population change is driven by three forces — a falling fertility rate (now around 1.6 children per woman), an ageing population (19% aged 65+ in 2021) and net migration that peaked at around 944,000 in the year to March 2023.
An older population places pressure on the NHS and adult social care — older patients stay in hospital longer and need more chronic care. Pension spending now accounts for around 10% of all UK government spending. Workforce shortages appear in nursing, teaching and engineering as the over-65 group leaves work faster than school leavers replace them.
There are positives too. Older people contribute through volunteering, unpaid childcare for grandchildren and the ‘silver economy’ of leisure, travel and home-improvement spending. Coastal towns like Eastbourne and Christchurch depend on retirees for local employment.
Migration Into and Within the UK
International migration is the largest single driver of recent UK population growth. Net migration peaked at around 944,000 in the year to March 2023, then fell sharply to about 204,000 in the year to June 2025. New arrivals have come from EU countries (especially Poland and Romania between 2004 and 2020), from South Asia and West Africa for work and study, and through humanitarian routes from Ukraine, Hong Kong and Afghanistan.
Internal migration also reshapes the country. London continues to attract young workers in their twenties, while families in their thirties and forties increasingly leave the capital for cheaper towns in the south-east, the Midlands and South Wales — a process called counter-urbanisation. Retirees concentrate in coastal districts like North Devon, parts of East Yorkshire and the Welsh coast.
The Housing Pressure
A larger, older and more dispersed population needs more homes. The 2021 census recorded 24.8 million households — up 1.4 million in a decade — and average household size has fallen as more people live alone in later life. The government estimates that England alone needs around 300,000 new homes every year to meet demand and improve affordability. Actual completions averaged closer to 220,000 in the late 2010s, leaving a persistent shortfall.
Pressure is not spread evenly. Demand is highest in London, the south-east and university cities like Bristol, Manchester and Cardiff. House prices in these areas have risen far faster than wages, and many young adults remain in their parents’ home or rent privately well into their thirties. Rural areas with strong second-home markets, such as parts of Pembrokeshire and the Lake District, have seen local people priced out.
England needs around 300,000 new homes a year to meet demand. In the late 2010s, only about 220,000 were built — a shortfall that pushes up prices, especially in London and university cities.
Around 60% of new homes in England are built on previously developed brownfield land — old industrial sites, former gasworks and disused railway yards. Planning rules favour brownfield because it reuses existing transport links and protects countryside. The remaining 40% takes greenfield sites: edge-of-town fields where building is faster and cheaper. Garden villages such as Northstowe near Cambridge and Bicester in Oxfordshire are large planned greenfield expansions.
Local authorities also approve home extensions and conversions of offices, shops and pubs to flats. Permitted-development rules relaxed in 2013 have since let tens of thousands of empty offices in England become flats.
Why It All Connects
The story of UK population change is not three separate trends but one feedback loop. Lower birth rates and longer lives age the workforce; an ageing workforce attracts younger migrants to fill the gaps; new arrivals and family-formers need housing where the jobs are; housing demand reshapes which areas grow and which shrink. Geographers track these flows because every government decision — on immigration rules, on planning permission, on social care funding — ripples through all four trends at once.