The government’s plan to boost housebuilding in this country by building on the so-called grey belt is “rushed” and “not properly thought through”, according to a Lords committee report.

The report from the House of Lords cross-party Built Environment Committee also found that the grey belt policy is unlikely to make any significant difference in the number of new homes that can be built.

The government argues that developing on land described as the grey belt, such as undesirable areas of green belt land, disused car parks and petrol stations, was one way it could reach its targets of building 1.5 million homes by the end of this parliamentary term in 2029.

However, the Lords committee said the government “appears to lack a sufficient understanding of the implications of introducing multiple intersecting planning policies at the same time”.

This compromises the government’s ability to deliver “any of its policies in a coherent way”, it added.

The report said it was unclear how much environmental concerns and worries about access to infrastructure such as public transport, schools, and parks had been considered.

“The government also does not seem to have any plan to measure progress or determine the success of this policy,” said Lord Daniel Moylan chair of the Built Environment Committee.

“Effective policy must be evidence-based and be able to demonstrate its efficacy. Sadly, this is not the case here,” he added.

In response to the report, a spokesperson for the Department of Housing, Communities and Local Government said it was “overhauling the broken planning system”.

“Our green belt reforms are informed through widespread consultation and will unlock more land for the homes and infrastructure communities desperately need, delivering sustainable, affordable and well-designed developments on low-quality grey belt,” the spokesperson said.

“This is just one of the ambitious housing reforms we have set out to solve the housing crisis and boost economic growth.”