Underfloor heating: luxury and a sound investment

Improving your home is a great way to increase your chance of catching a buyer's eye when the time comes to sell. But what's the best project to undertake to increase value and attractiveness?

In the past, estate agents suggested new kitchens or bathrooms, either of which could set you back thousands. A more recent trend is underfloor heating which, though initially expensive, can be cost-effective.

Underfloor heating is similar to installing a traditional central heating system, both in price and in process. "Think of it as like having a large, horizontal low-temperature radiator mounted in the floor," says Graham Poole, sales manager at Floor Heating Online.

With soaring fuel bills and a growing green lobby, energy-saving measures are becoming more important to househunters. But, according to the Nationwide Building Society, we also want warm homes – a lack of central heating knocks an average of 9 per cent off a property's value.

Nationwide also says that British homes are among the least energy efficient in Europe, responsible for 27 per cent of the UK's total carbon emissions. "In Germany, it's extremely rare to find a home without underfloor heating, and the situation is similar in Scandinavia," says Ian Mills of the Underfloor Heating Manufacturers Association.

Eco-friendly improvements help to cut costs and reduce emissions, which has prompted a number of government initiatives aimed at encouraging householders to undertake them. But too many are beyond the budgets of a lot of homeowners. Measures such as insulation are more straightforward, with nearly all properties in the UK eligible for some level of grant.

The boiler scrappage scheme launched earlier this year gives up to £400 off the installation of a new A-rated (condensing) boiler to replace those with a G rating. Any boiler over 15 years old is very likely to be G rated. But if you're considering this, you'll need to move reasonably quickly as the official vouchers are running out; so it may be worth considering a new heating system altogether.

Condensing boilers are ideal for underfloor heating. But in many UK homes the boilers are supplying the heat to a dinosaur system. Condensing boilers condense only when the return flow of hot water is below 60C, but traditional central heating via radiators often involves a return flow of around 60C-70C.

Trends come and go in heating. Yet, radiators have pretty much remained the standard and there's been a long-running debate over whether radiators are energy efficient. The short answer is no. Regardless of the fact that radiators don't allow many new boilers to function in accordance with their environmentally friendly credentials, to experience the full benefits you'll probably have to climb up on top of the wardrobe, as the hot air rises to the ceiling. The energy required for underfloor heating can be as little as two-thirds that needed for standard central heating.

The cost of materials and installation varies, but you will face a bill in the thousands. Against this, the new system will add value to your home, unlike some other so-called improvements.

Berkeley Homes already uses a variety of systems of underfloor heating in its developments – gas, electric and exhaust-air heat pump. The last involves taking air from warm parts of the home, such as the kitchen and bathroom, and using it to heat the water supply for the underfloor heating. This is the beauty of such a system. Unlike radiators, it's warm water that is required. A timber floor, for instance, needs water at about 40C, and any source of heat can be used.

Air heat pumps now qualify for a grant of up to £900 and can be used instead of a boiler (enabling householders to take advantage of the £400 boiler scrappage scheme). The pumps are up to 310 per cent more efficient than a modern domestic boiler. Because it's recycling air, for every 1kW of electricity used to run the pump, 3.1kW of heat is circulated, in comparison with just under 1kW of output from a standard boiler.

Heat pumps can be used to heat traditional radiators, too, allowing a mixed system of underfloor heating in extensions or refits combined with existing radiators elsewhere.

A retrofit system – lifting floorboards and fitting pipes between existing joists, for example – will cost more than working from scratch, but here the British obsession with DIY comes into its own. Laying the pipes and connecting them to the manifold is relatively easy. "Any competent DIYer should be able to manage it," says Graham Poole. The manifold can then be connected to the heat source by a qualified plumber. A DIY kit for a three-bed house of 120 square metres will cost between £3,500-£5,000.

One downside is that bathrooms are harder to heat as the bath absorbs much of the floor space. But elsewhere, an underfloor system will feel like the height of opulence, consigning slippers to the dog basket – but the dog won't be in the basket: will be sprawled across the floor.

Underfloor Heating Manufacturers Association ( uhma.org.uk) for a list of members for supply and installation; Floor Heating Online ( floorheatingonline.com) sells systems and accessories; the Energy Saving Trust ( energysavingtrust.org.uk) for details of grants and different ways to save energy

'We can arrange rooms just as we like without radiators'

Karen Mayne and her husband, George, installed underfloor heating in 2003 when they moved into their Victorian farmhouse outside Ryde on the Isle of Wight

"We chose underfloor heating principally for the flexibility of not having radiators, which limit your wall space and how you can arrange a room," says Karen. "Also, because it gives a more even heat. We have the heating under floating wooden floors, and they work really well. It's lovely underfoot and animals love it." A word of warning, though. For Christmas, Karen's daughter bought her a pair of chocolate stilettos, which sat under the tree. On the 25th, she opened a melted puddle of chocolate.