A major regeneration project that is set to deliver hundreds of homes could be in jeopardy as inflation soars and planning rules change. 

The plans for 1,500 homes and a civic centre in Harrow could be reviewed after it emerged some of the current schemes were unaffordable. 

Increasing building inflation costs and rules developers must follow to make projects more environmentally-friendly were to blame. Some projects could have pricey heat pumps and better glazed windows added.  

A Harrow Council scrutiny committee heard how the development at Byron Quarter – where there are plans to build 337 homes – cannot go ahead based on current designs. 

The Harrow Strategic Development Partnership – a £690 million venture between the council and construction company Wates Residential – hoped to market half the Byron Quarter flats as affordable. 

However, the new financial pressures mean it will have to amend the scheme for it to still go ahead. This could mean adding more properties to the mix or reducing the number of affordable ones. 

The partnership could also seek to secure further funding, add shops or commercial space or delay the building process to address the "challenges" it faced. 

Julian Wain, a consultant working on the project, said: "The cost of the scheme has risen at a time when, at the moment, sales values are not similarly increasing. 

"That is not to say this scheme is never going to be viable. It is not to say this is a poor scheme. 

"Based on the current scheme, the current level of height, the current approaches and the current level of affordable housing, it is not currently viable."

Similar pressures may affect Poets Corner, the Harrow Civic Centre site, where are plans to build around 1,000 homes. 

Mr Wain explained the partnership was "slightly less concerned" about the situation there as there was already scope to increase the number of properties and the building project would be spread out over a longer period. 

The extra costs will also have an impact on plans to redevelop Grange Farm and a report presented to the scrutiny committee showed Wates have been looking at how to tackle this since November. 

It plans to look at the possibility of adding more units to the site to make it more affordable, or will see how it can save costs by making the planned buildings more energy efficient.