High property prices, the exorbitant cost of childcare and an insufficient number of care homes to accommodate an ageing population are prompting many families to invite the grandparents to move in. The cost of residential care is another incentive: bills of £23,000 a year or more can soon wipe out inheritances. Research from B&Q shows that 750,000 homes in Britain are occupied by several generations, with the figure likely to soar to 1.75 million by 2038.

Sandra and Stephen Saltissi were pioneers: they invited Stephen's mother, Betty, 83, to live with them when they moved to Liverpool 24 years ago. Betty, who had turned 60 and was living in Brighton, had just left her job as company secretary for a literary agent. Stephen had accepted the job of consultant cardiologist at the Royal Liverpool Infirmary, and the family was relocating from Stockton-on-Tees with their daughters, Nicola and Caroline, who were toddlers.

“I worried about Betty living so far away,” says Sandra, 56. “With young children, we wouldn't have been able to drop everything if she needed us.” Having failed to find a house with a granny flat, the family opted for a four-bedroom detached 1920s property because there was enough room for an annexe behind the garage. Betty paid for it after selling her home, but the flat is technically owned by Stephen and Sandra. “We wanted Betty to be independent,” Sandra says. “The flat has its own front door and is self-contained, but she comes to us once a week for a meal and I take her shopping. When the kids were young, she helped with the babysitting. They now have a special bond with her.”

The arrangement has also worked well for Betty: “I have my son next to me, and my total independence. I might see him a few times a week and I see Sandra every day. When the girls were little, I did a lot of babysitting. I feel very comfortable to be in a family.”

Having a space suitable for older people is vital, says Joe Oldman, housing policy officer at Help the Aged: “You can adapt many features of an ordinary home. A lot of doorknobs are difficult if you have arthritis. A downstairs shower is easier to get into than a bath, and some uPVC doors have a lip, which makes wheelchair access difficult.” B&Q has launched a range of products with the elderly in mind, including walk-in baths (£2,200), special tap levers (£30) and ovens with side-opening doors (£399).

Equally crucial is honest communication. Christine Northam, a counsellor at Relate, says: “It is essential to talk through all the practical aspects such as cooking and shopping. But also, when an elderly relative moves in, old grudges may resurface. People need to be honest about their feelings for their mother-in-law.”

www.christinenorthamcounselling.co.uk;

www.helptheaged.org.uk; www.diy.com

Top tips

Before an elderly relative moves in, discuss every aspect of the move with the entire family.

A new-build or conversion in the garden is an ideal way of having your relative close by without compromising either their independence or your privacy.

If a separate building is not feasible, change a window into a door to make a private entrance. Separate living rooms and kitchens allow everyone their own space.

Install suitable window openers and doorknobs.

Be open about money. If the cost of the new quarters comes from the sale of your relative's home, siblings might feel that they are losing out on their inheritance.

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