World War One airship hanger and James Watt's workshop are among buildings added to English Heritage 'at risk' register

The foundry where James Watt’s steam engine was built is among 52 new entries on English Heritage's Buildings at Risk Register for 2007.

The Soho Foundry is joined by a World War One airship hanger on the list of buildings considered to be under threat by English Heritage. It said £400m was required to repair the 1,235 buildings on the list.

Chief executive Simon Thurley said: “What makes these buildings expensive and difficult to revive is a combination of factors such as their vast scale, the fact that part of the site is often a structure which can only be preserved but will never have a beneficial use, such as the pit-head winding gear at Chatterley Whitfield Colliery, and in some cases also their inaccessibility.”

Sixteen of the new additions will need about £65m to safeguard.