We disagree with BD (Leader June 2) that the Commonwealth Institute "would not be a huge loss if it were to go". It's a fabulous and dramatic bit of post-war architecture, with a great bit of landscape design by Sylvia Crowe. It's also a very popular landmark. In the last week, we've been inundated with messages from people praising the building.

Its problem is not that this is an uneconomically viable building - we have been told that until the trustees stopped renting it out it was generating an income of around £2 million a year, which is more than enough to repair the odd leak. There is little doubt that if it were offered for sale at a reasonable cost - with options for reuse that would allow continued public access - there would be buyers. However, like many buildings, its cleared site could be worth much more. That's why we have listed building legislation.

Catherine Croft, director 20th Century Society