'Houses keep coming into my mind,' says John Adams, head of the major projects architecture team at English Heritage, 'especially those built during the first half of the last century, because they respond to enormous social changes and technical innovation.'
As a student he tried to visit Frank Lloyd Wright's Robie House but found it locked up and derelict. ('We sent money back to the restoration fund.') Last year he returned. 'It's a beautiful elegant ship.
The most wonderful thing is the way you enter this tight little hallway and come up onto the upper deck. Then there's the magnificent fireplace, the main activities are organised around it. It must have been a very different way of living for its time - it still is.'
The Rietveld-Schroder House in Utrecht is another favourite. 'It's a furniture maker's house. It's very small and, in the Dutch way, makes maximum use of space. Mrs Schroder put up refugees on the top floor during the war.'
Adams has lived in Mexico and admires the work of Luis Barragan. 'His own house is built out of simple materials, there's no engineering gymnastics, it's all done with tremendous sensitivity to the larger landscape.'
Other houses - 'Soane's, of course,' Corb's Villa Savoye, 'entirely to do with moving through space', and in London, the Hopkins' house in Hampstead (pictured), 'like a breath of fresh air when I first saw it, done so quickly and effortlessly, yet with great sophistication.'