A crumbling 18th century church will be partly demolished and transformed into flats – in a move branded “crude and insensitive” by campaigners.

Stained glass windows from St George’s Church in High Street, Brentford, and the Sarah Trimmer Hall will be knocked out to make room for four flats, nine houses and a maisonnette.

Councillors gave the green light to the plans on Tuesday, despite the lack of parking and affordable housing usually demanded by planning officers.

Pleas by the Victorian Society’s historic church advisor, David Garrard, to retain the stained glass windows in any restoration of the church were ignored by councillors, who claimed the building would benefit from a cash injection as it was so dilapidated.

Mr Garrard said: “Short of outright demolition, this scheme represents as complete a negation of the historic character of the church as is possible to conceive.

“Not only will the spatial qualities of the interior be wholly lost, but, more importantly, all the external features that make the building pleasing and distinctive will be destroyed.”

Developers Hordon Cherry Lee, who sent glossy colour brochures to all councillors before Tuesday’s meeting, have included one disabled parking space but promised to give all owners a free two-year car club membership.

Speaking at the meeting Councillor Bradley Fisher said: “I am really concerned about the level of parking provided, but I would much rather see the area developed than turned into a heap of rubble and a car park.”

The former museum’s stained glass windows, which will be knocked out for entrance doors, will be placed in Gunnersbury Park Museum or Kew Bridge Steam Museum.

The church, owned by the Diocese of London, became redundant in 1958 and was used as a museum until 2006.

It is the latest money-making scheme by the diocese, which plans to rent out the roof of St Stephen’s Church in Parkside Road, Hounslow, for a mobile phone mast.