The need for city, town and village growth has led to one-tenth of the land in Calderdale being developed, figures reveal.
With the country's population set to reach 70 million by 2030, environmental campaigners say building new homes and infrastructure cannot come at nature's expense.
In 2017, some 10 per cent of land in Calderdale – 35 square kilometres – was developed, according to recently released data from the Ministry of Housing, Communities and Local Government.
This compares to eight per cent of land across England, with homes, offices and rubbish dumps among the uses.
In Calderdale, forests, open land and bodies of water were the biggest users of land, taking up 47 per cent of the overall area.
In second place was agriculture, which takes up 34 per cent.
Green belts, scenic sites preserving the countryside around urban areas, stretch across about 63% of the land in Calderdale – compared to 13 per cent nationwide.
The protected areas can be developed but are subject to tight building controls.
Overall, five per cent of land within Calderdale's green belt boundary is now classed as developed. This compares to eight per cent across England.
A further 460,000 homes have also been planned on green belt lands.
Rebecca Pullinger, from the Campaign to Protect Rural England, said previously developed brownfield land provides enough room for new houses.
She added: "There is space on brownfield land for more than 1 million new homes, but if its potential is to be fully realised, the Government, councils and house builders must all take a brownfield-first approach to development.
"We should also be investing in the green belt to improve its value as a vital public resource, enhancing nature by planting trees and restoring wetlands, and improving access and accessibility so more people than ever can enjoy its benefits."
A spokesman for the Ministry of Housing, Communities and Local Government said: "We are clear that building the homes our country needs does not mean tearing up our countryside. In fact the green belt is around 30,000 hectares larger than in 1997.
"Last year only 0.02 per cent of the green belt was developed for residential use and often this development is around road and rail infrastructure in place long before green belt designation."