Open House weekend: Saturday 17 - Sunday 18 September 2016
Open House London is the city-wide celebration of the capital's fascinating buildings. This year 750 buildings, from government offices to private homes, will be open to visitors. There will also be neighbourhood walks, cycle tours, architects’ talks and debates - all for free.
The concept of the event is so successful it has spread to 30 cities across the globe, from New York to Melbourne.
Highlights this year include tours of the Crossrail tunnels - sign up to a waitlist for if tours are fully-booked - the Thames Barrier and the capital's most iconic buildings, such as 30 St Mary Axe (The Gherkin).
And for those more interested in peeking behind the curtains of other people's homes, more than 200 owners are opening their doors to show off their extension and renovation projects.
Some places you can just turn up to have a look around - and others you have to pre-book. You can find all of the listings here: listings.openhouselondon.org.uk.
Buy the guide: the official guide has the details of the 750 buildings opening their doors this year. Allow three-to-four days for delivery. £7 each. Order here or pick up a copy at the RIBA Bookshop, London Review Bookshop, V&A Museum Shop, National Theatre, AA Bookshop, ICA Bookshop Foyles, Museum of London, Persephone Books and Brick Lane Bookshop.
What will I find when I get to the buildings? At many of the sites, the Open House guides and stewards will show you around. Some are professional, some are amateur enthusiasts, all volunteer their time and knowledge.
Will I get to meet any of the architects? Look out for the entries coded as having architects on site; some will be giving talks and tours of some of the buildings they’ve designed.
Do I need to book? Entry to a few of the properties will require you to book in advance.
Of the tours you need to book, here's what's still available:
Baitul Futuh Mosque: the largest mosque in Western Europe, accommodating 13,000 worshippers. The building is a blend of Islamic and modern British architecture and was voted one of top 50 buildings in the world by Independent Magazine.
Castle Green: an extended PFI school and community facility in the heart of Dagenham with state-of-the-art facilities that have been developed in line with new pedagogy focusing on importance of communication.
Citypoint (Simmons & Simmons' offices): built in 1967 for BP, CityPoint was the first building in the City of London taller than St Paul's Cathedral. The building was refurbished in 2000, and its height increased to 127m.
Defoe Road: a complete renovation of 'The Old School Building', which had lain derelict for 15 years, into a two-bedroom family home.
St Mary's Convent: a convent in an 18th Century Grade II-listed house with original features.
The Coach House: a Victorian house retrofitted to save 70 per cent carbon.
Westminster Hall: one of the finest and largest Medieval halls in Europe with a magnificent hammerbeam ceiling, which dates back to 1097.
For more information and a full-timetable visit: openhouseworldwide.org