A population boom will see the number of people living in Kirklees rocket in the next 25 years.
And Calderdale’s population will also rise sharply, by an expected 11%.
New projections from the Office for National Statistics show England’s population will rise by 9 million in 25 years’ time, to 63.3 million.
And the number of people living in West Yorkshire is set to increase by 13% from 2.26 million in 2014 to 2.55 million in 2039.
The Kirklees region will see the second biggest West Yorkshire increase, behind Leeds. Measured in population terms, it is one of the larger local authority districts in England and its 2014 population of 428,279 is predicted to rise to just under 490,000. Calderdale’s population of about 210,000 is forecast to go up to about 234,000.
Wakefield will see the smallest increase in the county, up by 9.8%.
The figures are calculated based on life-expectancy, birth rates and death rates as well as the net effect of migration at current levels.
A Kirklees spokesman said: “The district’s population has been increasing steadily for many years and the number of new homes being built in the district has not kept up to demand.
“The council’s Local Plan is being prepared to create a 15 year plan to help plan effectively for new homes and jobs. The council and other delivery bodies are already planning for infrastructure improvements to complement the Local Plan proposals.
“Some types of infrastructure, such as doctors surgeries, are outside the council’s control to provide as they are private businesses but the council is working closely with other delivery agencies and governing organisations to align the Local Plan with their own investment programmes.”
Calderdale Council’s Cabinet Member for Planning, Housing and Environment, Clr Daniel Sutherland, said: “These population projections from the Office for National Statistics (ONS), together with their projections for Household Growth, are used as the starting points for assessing housing growth and trends for Calderdale Council’s Local Plan as well as planning for infrastructure provision.
“These figures show only a slight change in the 2014 projections, so we are already planning for this scale of change. The final draft of the council's Local Plan will be published later in 2016 and will show where development may occur and the likely infrastructure requirements to facilitate the growth.”
Tower Hamlets in London is expected to see the biggest boom with the population set to increase by 48.3% according to the ONS.
At the other end of the scale 10 areas are expected to see their populations decrease, with the biggest decline in Barrow-in-Furness in Cumbria with a predicted drop of 9.8%.