But with fewer taxpayers, there will not be the funds to provide them with personal care. So how are houses going to be designed to allow people to live at home?

The year is 2030. Mrs Smith, aged 98, turns to her electronic Companion to find out what medicine she should be taking.

An automated voice tells her: "You should take one of your statin tablets for your cholesterol."

It then says her supplies are getting low so she electronically orders more from the local pharmacist.

Looking up at a screen on her dining room wall, she sees an outline of her daughter moving around at her home 150 miles away through a "virtual frosted window".

Her daughter can also see her elderly mother, comforted in the knowledge that she knows she is up and about.

Later in the morning, Mrs Smith uses her Companion to have a video consultation with her doctor.

Ages

Fantasy? Maybe not. Experts are already making plans to keep people healthy and living independently as the population ages.

By 2050, the proportion of the population over 80 is expected to double to a third. As that happens, the demands on how houses are designed and kitted out will alter dramatically.

In Bristol, a pilot project is under way using the Companion, an easy-to-use computer system designed to help people shop and access health services electronically.

The device, created by a team at Brunel University and presented at a conference of the Commission for Architecture and the Built Environment, is in effect a scanner attached to a laptop.

Users can scan food or health items from a brochure and the information is then sent electronically.

Other features include a voice and text system to remind people to take medicine.

And with a camera or video built into the scanner, the owner is able to have consultations with pharmacists or doctors.

Brunel University engineer Justin Hall said: "We know elderly people were unwilling to embrace the internet so we wanted something more user-friendly.

"The scanner and bar codes were something that research showed older people were more comfortable with."

But the gadgets do not stop there. York University scientists are looking at integrating a range of technologies into houses.

One idea is the "virtual frosted window" which is designed to bring families closer together.

Money

"If your mother lives opposite you will see her moving around," said Professor Andrew Monk. "You can see she is okay and it reminds you to ring her. But not many people live opposite their family.

"The window is frosted so you cannot see exactly what a person is doing but we can see they are on the move and they can see you.

"It is like looking through a bathroom window but you can place it any room."

The government is also investing £80m for local authorities to develop telecare - digital systems to link elderly people up to care services.

Over 1.5m already have community alarms which hang around the neck and can link an individual up to medical services.

But in the future Professor Monk also believes telecare could include activity monitoring systems.

"They work on sensors which record each movement in a house. They could be placed in picture frames and alert someone - a doctor or family member - if the regular pattern of movement is altered.

"There could also be a system to record water usage. If a person usually goes to the toilet four times a night, but for some reason only goes once, this could mean something."

But Professor Monk believes some of the most important developments will be to solve the isolation and loneliness people can feel.

"Talking to the elderly, this is one of their major fears. I know of groups who have set up video and phone conference, a bit like businesses use. They all get to talk as a group and it can mean a lot to a person."

Such schemes have received the backing of government.

Jeremy Porteus, the Department of Health's lead on providing home-based care in the future, said: "The population is ageing, we cannot get away from that so we have to harness technology to help people live independent lives."

But it is not always the latest gadget that always holds the answer. Even with the advent of virtual realities and talking computers, the solution is sometimes a little more basic.

Roger Battersby, director of PRP Architects, said: "We have to look at what elderly people need. Sometimes it is as simple as putting hand rails in."