Architect Raymond Young cheers a happy melding of old and new in Dundee, and boos a much less happy one in Edinburgh

My wonder is the Dundee Contemporary Arts building designed by Richard Murphy Architects. It’s a lovely little building that seems to grow out of an old brick warehouse, with the entrance aligned to the street, of which it seems an extension. It’s not an icon standing alone and looking adrift, because it emerges from the very fabric of the city. The entrance is cleverly done in glass and steel so that it sweeps you in – you can’t go past without wanting to go in and find out more. The building effectively marks the regeneration of Dundee and people flock to it – there were 300,000 visitors last year, in a city with a population of 250,000.

My blunder is the office block on top of the St James Centre in Edinburgh, all eight empty storeys of it. It sits on top of a commercially successful shopping centre, right in the middle of Edinburgh’s New Town and next to Robert Adam’s Register House. Now it’s empty, nobody can do anything with it.

In the 1960s, we inserted new developments into old and delicate surroundings badly. By the late 1990s, buildings like the DCA managed to do it more sensitively. The DCA celebrates its location, has helped improve its neighbours and doesn’t dominate them.

Architect Raymond Young is chairman of Architecture and Design Scotland