National Park City's own WildHomes campaign and guide to gardening for Wild Londoners
Royal Society for the Protection of Birds, De Montfort University and Natural England research suggests paving over front gardens contributes to declining numbers of sparrows:
University of Sheffield Biodiversity in Urban Gardens (BUGS) Projects: research into the biodiversity and conservation value of domestic gardens in urban areas.
The original BUGS project was a detailed investigation of the biodiversity and habitats in gardens in a single city (Sheffield), completed in 2002. The second project involved similar work across five cities in the UK and ran from 2004-2007. The projects focused on back gardens.