One part in particular tells you that Gehry was thinking "house" when he designed this building. Go up the curving stairs into the turret, and you have a circular sitting room, complete with stove, with one enormous window, shaded by a big timber canopy, looking out across the Tay. Another square window in the roof high above your head lets you contemplate the clouds or the night sky as if you were in a "skyspace" by James Turrell. Anyone who goes there will want to live there. The centre's chief fundraiser, Valerie Busher, admits that she too really wants this place to be her home. You can only conclude from this that Gehry has succeeded by the simple expedient of imagining that he, too, might want to live there. All architecture, after all, derives from and comes back to the house. Get that right, and everything else follows.

Gehry has his detractors, usually people who are suspicious of the idea of architecture as sculpture. There does not at first seem to be a lot of form-follows-function about his work. My own doubts about Gehry tend to build up over time in this way - and then I go to see one of his buildings, and come away charmed. Gehry, who for the first half of his career had an utterly pragmatic grounding in reality working for big commercial firms of architects, has never lost that practical touch. Inside, his buildings work. They are not haphazard. Every space is thought through. I couldn't see an inch of wasted floorspace in the Dundee building.

Obviously that big complex roof is a costly indulgence. You cross your fingers and hope it doesn't leak. Not only that, but I would find its relentlessly busy, geometrically-overloaded underside just a bit too much, over a long period. Then again, maybe Gehry anticipated that. His tower room is a total contrast, as restful as the downstairs is active. And wherever you are in the building, you can always see past the structure, to the sky and the landscape. Perhaps it's a metaphor for seeing past the disruption of illness in your own life, to something more peaceful and assured. Or maybe that's just co-incidence.