The population of St Albans will increase by 9,200 over the next eight years, according to the Office for National Statistics (ONS).

In 2016 the population was 147,000. By 2026 it is expected to reach 156,200, a rise of 6.3 per cent.

Every two years the ONS estimates how the population of England will change over the next 25 years.

Statisticians study birth and death rates, and look at how the area’s population is ageing.

In St Albans the percentage of the population made up by pensioners is expected to rise from 16.6 per cent in 2016 to 18.1 per cent ten years later. And by 2036 the ONS thinks over 65s will make up more than a fifth of the area’s residents.

People are living longer due to improvements in healthcare and technology, however this puts greater pressure on the NHS and social care.

Head of planning for St Albans district council Tracy Harvey said: “We are currently working on a Local Plan (LP) that identifies land for future homes, jobs and infrastructure from 2020 to 2036.

“This anticipates population growth and includes a proposed target of allowing for 913 homes to be built a year during this period, an increase of 25 per cent to the district’s housing stock.

“The LP will also take into account the need for new schools, roads, leisure amenities, health facilities and other infrastructure.”

Caroline Abrahams, Age UK charity director, said: “The fact there are growing numbers of older people is a cause for real celebration, but these figures underline, once again, the need to ensure that our health and social care system is fit for the future.

“The Government’s decision to produce a social care green paper was welcome but realistically it will be years before its proposals impact in local areas, so action is needed now to shore up what remains of our care system.”

When calculating the population estimates for St Albans the ONS expects the birth rate to outstrip the death rate. Figures also show the female population is expected to grow slightly faster than the male population.

The statisticians then factor in people moving around England and immigrating from across the world, which is called internal and international migration.

The ONS estimates there will be an overall net increase of 1,800 migrants by 2026. The most significant increase was in migrants from other parts of England, with a net rise of 2,100 estimated.

Herts county cabinet member for growth, infrastructure, planning and the economy, Cllr Derrick Ashley, said they have acknowledged the challenges of an increased population: “We need to plan for more than 100,000 new homes and 100,000 new jobs in Hertfordshire over the next fifteen years and ensure we deliver infrastructure to support the growth, particularly in those areas where we have direct responsibility, such as schools and roads.

“We want Hertfordshire to be made up of economically, socially and environmentally sustainable communities, where people want to live and work.”

Andrew Nash, from the ONS, commented: “While the overall populations of all regions in England are projected to increase over the next decade, reasons for these increases vary greatly depending on where you live.

“For instance, projected population change in London is mainly caused by natural change - the difference between the number of births and deaths - and not migration.

“This is because London’s net inflow of international migrants is offset by a similar number of people moving to other parts of the UK.

“That contrasts with the north east, where growth is mostly down to migration. What’s also clear is that the population is ageing in all regions, with the number of people aged 65 and over growing considerably faster than younger age groups.”

Population growth in St Albans was below the average for the east, where the population is expected to increase by 7.3 per cent by 2026.

The average growth rate across England was 5.9 per cent and the ONS predicts that by the year 2041 the population of St Albans will have grown to 164,900.