Part of a former mental health asylum in Ealing which dates back to the 18th Century has been bought by London developer and housing association Catalyst to create 270 new homes on the site.

The sale, worth £14million, will provide private, shared ownership and both affordable and social rented accommodation on the disused areas of St Bernard’s Hospital in Hanwell.

The trust is investing the sale proceeds in the construction of a new medium secure hospital elsewhere on the St Bernard’s site. This will allow us to improve the facilities in which we care for patients as well as the care we provide to those in need.

Ealing Council has given outline planning permission for five new residential apartment blocks on the site. To date, full planning permission and listed building consent has been given for:

• the conversion of the Gatehouse into café, retail and office space

• the conversion of North House into six private apartments

• construction of a new building called North East House to restore the Georgian symmetry to the Gatehouse and chapel view.

Many of the other buildings included in the sale are of poor quality so will be pulled down. The other areas sold are no longer considered to be suitable settings for the trust to provide modern mental health care services to patients.

Eric Munro, director of estates and facilities at West London Mental Health NHS Trust , said: “We are delighted that this surplus land will be used as part of a substantial regeneration of this part of west London. We see this as good use of a site which was falling into disrepair and will now be redeveloped to provide prestigious housing. In addition, it will help the trust carry out its much needed redevelopment in a more cost effective way that lessens the burden on taxpayers to foot the bill.”

As part of the agreement, the site’s Chapel will be retained for community use. However, whilst the developer finalises construction proposals for this building, West London Mental Health NHS Trust will continue to use it to provide services and events for a short period of time.

Tom Titherington, Catalyst’s director of business development & market intelligence, said: “Securing this strategically important site, which, being in Southall – one of the Mayor of London’s Opportunity Areas – is poised for major improvements over the coming years, is central to our strategy to grow our presence in London and the south east.”