Over 800 buildings across London's boroughs open their doors to the public for one weekend. Under this year's theme – Revealing – Open House turns its attention to the issues affecting local communities as the urban environment evolves. Regeneration and "eco-builds" are key themes reflected in the new additions to the programme. Nick Barker's timber framed 25C Montpellier Road, and turf-roofed Ott's Yard by vPPR Architects represent the type of sustainable architecture that is emerging across the capital. Tours of properties, by bus, bike and on foot will be led by industry experts.