If you’re a bit of a nosy parker, put your skills to good use at this annual event for which more than 700 buildings unlock their doors to the public. Check out architects’ homes, eco buildings, major regeneration projects, government buildings, 17th-century mansions and historic landmarks. For the first time, the Commonwealth Institute in Kensington (pictured) will be open – it’s the last chance to witness its 1960s architecture before it undergoes a redesign.

Sept 17-18
Various locations