Overcrowding is a problem which increasingly affects families in social housing in dense urban areas in the UK. In severe situations it can impact on the well-being of family members and compromise the life chances of a new generation of children and teenagers growing up in inner London. We have worked for five years with Camden Council’s overcrowding team to assess potential for residential extensions and conversions to provide additinal living space. Six residential extensions have recently been given planning permission with works on site starting in April 2011. The extensions have all been individually designed to cater for the specific needs of each family and the urban context of each site. At a time of spending cuts the Camden Extensions provide a cost effective and sustainable contribution towards alleviating overcrowding.