Why does this matter? Because it is depriving elderly people of housing choice and making it difficult for retirement housebuilders to meet the increasing demand for their product.
Councils are supposed to provide a huge range of services to the people who live within their jurisdictions. They collect their rubbish, educate their children, provide social support, swimming pools, car parks, business advice … And they provide housing services, mainly by setting and enforcing rules for the amount of housing that must be built by private developers. Unless, that is, you belong to the rapidly growing element of the population that is over 60. In that case, the chances are that you're on your own.

It is forecast that 1 million single-pensioner households will be created in the next 13 years. About three-quarters of those households will be owner–occupier. Most of them will be living in family houses that would be better used for housing families, or will trade down to easy-access apartments in conventional housing schemes.

A better solution would be to care for them within purpose-built developments. Age Concern says: "We would like to see a range of housing, including one and two-bedroom housing, bungalows, ground floor and sheltered accommodation. The design, location and management of newly built housing needs to reflect the increasing numbers of older people."

The problem is that when a housebuilder such as McCarthy & Stone tries to put up a development designed to accommodate the needs of elderly people, it finds that it is treated just like any other private developer. Instead of perceiving its planning applications as fulfiling a social need, local authorities make demands for affordable housing. They do this because they don't have strategies for housing elderly people – hence the McCarthy & Stone questionnaire referred to above.

"We've got ourself a reputation, which is unjustified, for objecting to affordable housing policy," says Gary Day, McCarthy & Stone's planning director. "But all we have ever tried to do is ensure a level playing field. There's a blinkered approach by local authorities.

"In the past we would never be required to provide affordable housing. Now some local authorities look at our planning proposals, see that a scheme is over the unit threshold for affordable housing requirement and say it must be included.

"Mainstream developers have more flexibility on unit numbers. We would develop 40 units for a scheme, and the planners automatically want affordable housing. We then have to tell the vendor of the land that the price of the land is reduced, and so the vendor sells to a mainstream housebuilder instead."

Retirement housebuilders can ill afford to lose land opportunities; the emphasis on brownfield development has meant the town-centre sites that were prime targets for retirement housing are being sought by mainstream developers.

"Of 37 sites brought forward we have only bought seven because of planning problems," says Peter Askew, managing director of Pegasus Retirement Homes and chairman of the Retirement Housing Group, which is affiliated to the House Builders Federation. "Retirement homes are more expensive to build and then you get hit by affordable housing. Many mainstream housebuilders contemplating moving into the sector think: why should I take the trouble?"

Askew reckons that Pegasus' lifetime homes, which have knock-out wall panels that allow them to be converted to accommodate a carer, cost about 2.5-3% more to build than standard retirement homes. Unlike mainstream developers, retirement housebuilders give about 30% of floorspace to communal and management facilities, and have to be particularly mindful of long-term maintenance and management.

Pegasus has tried to come up with solutions to its planning obstacles. For a project in Ealing, west London, the housebuilder offered to hand over to the local authority some of the large family houses that it would be taking on in part exchange from some of its customers. "The council couldn't cope," recalls Askew. "It couldn't come up with any calculation to measure it."

In his role at the Retirement Housing Group, Askew will be working to influence the policy-makers. The government is likely to lend a sympathetic ear. It produced a report in February, Preparing Older People's Strategies, which set out the guidelines for local authorities and noted that older people are often overlooked in planning agendas. The government has also established a Housing and Older People Development Group, under John Prescott, to promote, advise and measure improvements in the supply of housing for elderly people.