The British Property Federation has broadly welcomed Ken Livingstone's early proposals for the London Plan, but warned that the mayor would be wrong to make decisions on building applications based on 'design merits'alone.BPF director general William McKee said: 'Design is an issue that is inherently subjective. If we are to be allowed certainty in the planning system, the mayor should leave design issues to the experts and local community.'The BPF said it was encouraged by Livingstone's comments that the GLA was a 'progrowth organisation'. But Coin Street Community Builders has criticised the London Plan for being 'significantly wrong' in its approach to the capital's problems. It said a number of issues, including over-reliance on commercial development and tall buildings, were 'fundamental weaknesses'and 'simplistic'.