Open house weekend is round the corner and you have to put your name down early for chance to win the ballot and ogle the inside of Number 10, the Gherkin or the BT Tower. But happily out of the 700 buildings you could visit some of the best are right here. Take the super-eco home for slim people. It is appropriately called The Gap House and is only 8ft wide. Choose this fantasy interior in a Victorian flat (pic) intended to be enjoyed as a dreamlike escape from the outside world. Each room has a different style – Gothic, Renaissance, Baroque, Roccoco, Victorian, Regency and Modern. Box of allsorts at 155 Holland Park Avenue. Or how about this fabulous 3floor-in2 Apartment (pic right) a project where two old flats have been conjoined, with a dramatic full height vertical space: a stair rises through three levels that shape this new tall atrium and link into the two main previous floor levels. Sunlight beams into the lower, previously shaded north spaces. Let there be light at 17 Elgin Crescent.