Even during the boom, it was difficult to see some of the things we were building and imagine them as a success. Enormous luxury golf and spa hotels in the middle of nowhere, shoe-box apartment blocks in small towns, ghost estates where no houses were ever sold, and massive out-of-town retail and industrial parks – all these have blighted the landscape, and now stand in various stages of construction or dereliction, mocking us with the question: what should we do with them? Some ways out of such waste have already been proposed: turning the hotels into nursing homes is one example. Or we could look to SoHo in New York, where inner-city factories and warehouses became, first, artists’ studios and then ultra-desirable loft apartments. But when Shelley McNamara and Yvonne Farrell, of Grafton Architects, told me about a project they were doing with students in Switzerland, imagining the creation of a school out of an abandoned village (each house becoming a classroom, with civic buildings as canteen and offices, and the streets as a playground), I realised that architects are the holders of solutions too. Architects are trained in creative thinking about how we live. It is true some members of the profession had a hand in fashioning the chaos we’ve created, but just as many spend time and effort thinking about how we can plan better, build better, live better. Here, four architects respond to the question of what should be done with our “problem” buildings. The only stipulation was nothing could be knocked down.