A lack of new well-designed family homes for sale could undermine government plans to revitalise Britain's inner cities, according to research for the Joseph Rowntree Foundation.

Unless developers build more homes suitable for growing families in the new mixed income housing developments, then hopes to improve schools and services for families already living in inner city neighbourhoods may not be realised.

Mixed income new communities (MINCs) comprise homes for rent, part-ownership, and outright sale. The report argues that for these communities to achieve their neighbourhood renewal goals and be sustainable in the longer term, they need to attract better-off families, not just childless households, and to give childless couples the opportunity to remain when they have their own families.

The researchers, from the Institute of Education and the London School of Economics, found that better-off families were attracted to living in MINCs by safe, clean, and friendly neighbourhoods with open spaces for children to play.

The families preferred developments where social and market-rate housing were integrated and had the same standards of design. Good management and community development were critical to success.

But, after focusing on four contrasting inner city MINCs, the study found a problem with the supply and cost of family homes. Building family homes for sale had been an important element in the master plans, but:

• They were not always built in sufficient numbers, or were too small or poorly designed for families. In two newly built London neighbourhoods that were studied, 8 out of 10 private homes had only one or two bedrooms;
• In regenerated low income neighbourhoods, more family homes were built and families on moderate incomes bought them in the initial stages. But as land values rose, these households could not afford to move to larger homes as their families grew and similar families could not afford to move in.

The result was that in all four areas studied the proportion of families with children in the private sector homes was considerably lower than in the population at large.

The researchers found a number of constraints on the supply of family accommodation:

• Government building targets: these have been set in numbers of ‘units’, without regard to the number of bedrooms, thereby favouring small new homes.
• Developers' reluctance to experiment with flats for families: in spite of successful examples in other European countries, developers assume that families and flats are incompatible.
• Land value: where land values are high and there is a demand for one- and two-bedroom flats, developers prefer to build these rather than family homes.

The report recommends that the Government could invest in some demonstration projects, working with developers and local authorities, to highlight how family accommodation might be successfully provided in the inner cities. It suggests that local authorities and regeneration partnerships should raise the issue of building family homes for sale as an explicit social goal as they enter into partnerships with housebuilders.

The four mixed income new communities examined in the study were at Hulme in Manchester, New Gorbals in Glasgow, and Greenwich Millennium Village and Britannia Village both in London. Much of the good practice identified in the study was at Greenwich Millennium Village, the success of which underlines the value of getting mixed neighbourhoods right.

Ruth Lupton, co-author of the report said, "Families do choose to live in mixed income developments if the design and management of these schemes is right. Central and local government need to consider these issues with developers if they want families to be part of the means of revitalising our inner cities."