Sustainability group Sponge is offering two walks as part of the London Open House weekend

London Open House and the Sponge Sustainability Network have teamed up to offer eco-trails to Londoners鈥 who want to experience the best South London has to offer in sustainable design and construction.

As part of the London Open House Weekend 2007, which takes place on the 15 and 16 of September, two eco-trails are being offered to people who will get the chance to see a diverse range of modern sustainable developments and cutting edge design in South London.

Sponge Sustainability Network is a network of over 2,500 young professionals who share an interest in sustainability. The group said the walks would focus on upgrading existing buildings rather than new environmentally-friendly schemes.

The free Open House London annual event gives the public the chance to experience and explore 600 buildings all over London that aren鈥檛 normally open to the public in order to celebrate the cities design and excellence. The walk on Sunday will include a tour of Quay House, in south-east London.