The Bowes Museum in Barnard Castle, Durham, has received a £250,000 cash injection towards its five-year redevelopment programme from the Garfield Weston Foundation (GWF).

Established more than 100 years ago by John and Joséphine Bowes, the French-style château houses thousands of objects, including furniture, paintings and sculptures from across Europe. Work began on the transformation project in 2005, with repairs made to the building's leaky roof. The second and third phases of work, including the creation of a silver and metals gallery – due to open in April – and a new café and shop, are also nearing completion.

The latest grant will now go towards the fourth phase of work, which will see the creation of a new gallery dedicated to British decorative arts, revamped second-floor picture galleries and improvements to the main temporary exhibition space. A second temporary exhibition space will also be revamped to display community-based and small-scale exhibitions.

The work is being supported by a range of partners, including the Heritage Lottery Fund (HLF), English Heritage and the DCMS/Wolfson Museum and Galleries Improvement Fund, as well as GWF, Durham County Council (DCC) and One NorthEast through the County Durham Economic Partnership. Adrian Jenkins, the museum's director, said: "The GWF was a major player in contributing towards the first phase of work to make the building watertight. We are therefore delighted that it has chosen to support this latest phase with a further grant of £250,000."

The Bowes Museum receives a core funding grant from DCC and receives support through the DCMS's Museums, Library and Archives Council Renaissance programme. Additional funding for its exhibition programme also comes from the Northern Rock Foundation.