While high property prices are putting home ownership increasingly out of reach, the supply of affordable family homes has plummeted.
Young singles and childless couples have been the main beneficiaries of the affordable housing boom of recent years. The vast majority of new-build homes have been small flats rather than houses or larger apartments suitable for families.
Faced with calls to boost supply, the Government is backing a proposal urging councils to sell off their most expensive houses and increase the number of cheaper homes built. Mayor Boris Johnson has launched an "overcrowding action plan" to halve the 207,000 households living in cramped conditions.
One initiative aims to persuade "under-occupiers", typically middle-aged council tenants whose children have flown the nest, to downsize to smaller accommodation and free up the larger home. In tandem with this, housing associations are increasing the output of family accommodation for rent and shared ownership.
In London, modest two-up, two-down terrace houses with a garden start at about £275,000 (in Lewisham and Leyton, for example) and rise to about £675,000, according to estate agent Winkworth, which has a network of branches across the capital.
But even the lower figure is beyond the price range of many family buyers, which is why shared ownership is appealing.
Maisonettes and larger flats as well as new houses are being built, sometimes with family-friendly amenities such as allotments and secure play parks for children.
Family Mosaic specialises in this sector and is offering part-buy, part-rent homes in attractive, well-connected parts of London where the entry price is less than £140,000.
"Often families and couples expecting a child believe they can't afford to buy a property that meets their size and location requirements. But shared ownership makes it possible. And with the low mortgage rates currently available, now is a good time to upsize," says Lauren Nicholson, marketing director.
For the last 80 years Loxford House, close to leafy Highbury Fields, was the headquarters of charity Action for Children. The handsome Victorian building sits in mature grounds, which have been enhanced following the site's redevelopment into private and affordable housing. Called Highbury Park, new three-bedroom homes are priced from £156,750 for a 35 per cent share.
Highly energy-efficient, the homes also boast much lower running costs, resulting in savings of up to 55 per cent (about £1,300 annually).
More three-bedroom homes are available at The Old Timber Yard, near Crouch End, and Harper Square, close to Borough, in the SE1 postcode. Prices are from £139,125 for a 35 per cent share. Call 020 7089 1315.
Creating an environment for families in a gritty, inner-city neighbourhood requires fresh architectural thinking.
More than 60 three-and four-bedroom townhouses with private gardens have been built at Mastmakers Road, Docklands. This scheme is an integral part of the fancy 1,000-home Baltimore Wharf development, where private-sale apartments rise to over £1 million.
It is one of the most family-friendly new housing complexes in London, demonstrating that it's possible to combine a range of tenures and unit types within a high-density scheme without compromising on quality or space.
A cluster of linked buildings is set around a playground, community garden, courtyards, allotments and a sports pitch.
Buildings have "bio-diversity" roofs and residents benefit from lower energy costs because of a combined heat and power plant on site.
Shared-ownership homes become available as people move on. Call One Housing Group on 020 8502 5758.
Glasshouse is a new development in Shadwell, midway between the City and Canary Wharf, and well located for riverside recreational facilities and amenities. The development also has a secure landscaped courtyard and children's play area.
Three-bedroom apartments start at £77,500 for a 25 per cent share. Total household income must be less than £77,200 to qualify. Call 0800 118 2025 or visit genesishomes.org.uk