Property: Super-Lego meets mail-order

In Japan you can flip through a virtual catalogue, choose the components of your dream home and sit back and wait for the factory to deliver it. Welcome to the future, says Andrew Mylius

House hunting - foot-slogging, surveying, bidding, gazumping - can be an experience full of angst and heartache. But it doesn't have to be that way. With the aid of computer modelling, would-be home owners in Japan custom-select their new abode from a kit of parts.

Having tried different configurations on for comfort "virtually", their final choice is relayed to factories where modular parts are made. The modules are then delivered as separate components and fixed together on site. From visiting the estate agent to moving in takes about 16 weeks.

This system of home building - super-Lego meets mail-order clothes shopping - has been normal in Japan for more than a decade. Chris McCarthy, a partner at the engineers Battle McCarthy, says: "At an international level housing is exportable. You can make things in one country and build them in another. As far as the Japanese are concerned, that can be thousands of miles away, so long as the product is high value."

The transglobal migration of brown and white goods proves his point. Meanwhile, at the product design group DCAb, the managing director, Tom Barker, thinks the construction industry will soon be competing world- wide for contracts in the housing market. As a result, after killing off prefabrication and system architecture in the late 1960s and 1970s, UK constructors are starting to sit up and look afresh at factory-made houses.

Groups investigating new house-building techniques such as Taylor Woodrow, Countryside Properties and Berkeley Homes believe the market will be moved equally by "supply-side" push and "demand-side" pull. Both manufacturer and consumer stand to benefit from an overhaul.

While Alan Cherry, chairman of Countryside Properties, believes the Brits have a love affair with bricks, Nick Thompson, an architect partner at Cole Thompson Associates, is critical of housing that consists of smaller and smaller brick boxes: "It's selling yesterday's technology to a captive market." Today's technology offers open, flexible space and high performance to a generation of home-buyers raised as consumers and used to exercising choice.

Allan Kell, executive manager of the European Intelligent Building Group, is currently working on an experimental house type for mass-production - the Integer project. "People jump to conclusions about how a house of the future looks," he says. "They imagine a sci-fi pod on a stick." Concept houses, though, are seldom more than one-offs. As a result, Integer is deliberately steering clear of prescribing any aesthetic. The focus is instead on the way the building works. If local materials perform, incorporate them, is its attitude. The aim is to deliver a high-volume product that is at least a third cheaper than conventional housing at erection stage, is more efficient to run and lasts longer as well.

"You could ask: `What is great architecture?'" says Bernard Hunt, managing partner at Hunt Thompson. "That can be a distraction. There's a confusion between art and architecture. Really successful architecture is where people achieve a better quality of life. Many things in architecture haven't caught up with computers and cars for instance."

Toyota is one of Japan's largest housing manufacturers, applying to buildings the same "lean production" principles - short lead-times, flexible specialisation, and task automation - that have helped it to dominance in the motor industry. It is instructive to note that John Egan, ex-chief of Jaguar and current head of the British Airports Authority, will report to the Government on efficiency in the UK construction industry later this year. Mr Kell notes: "Frankly, the British construction site isn't renowned for its efficiency." Richard Hodkinson at Taylor Woodrow agrees: "Working in a factory is far more efficient than working in the rain."

Factories, simply, allow for better control of the production process. They are convenient for the constructor and represent improved value for the consumer. Mr Barker notes that in Japan factory-made housing caters to the top end of the market. "They sell at a premium because they're `manufactured'. What they sell on is the fact that the factory gives you special qualities," he says.

Time and money drive the streamlining of house construction. Factories not only deliver houses regardless of weather; they are safer to work in and, explains Mr Hodkinson: "If you cut down the number of components on site you cut down waste. If you bring a high-quality part to a site you need to protect that item and commission it separately. Factory production could help you to incorporate high-quality doors and windows." Meanwhile the opportunity to dramatically cut the 70 million tonnes of on-site waste generated by demolition and the construction process itself will be received enthusiastically by builders. Chris McCarthy predicts landfill will soon be charged at pounds 15-20 per tonne. "Don't demolish, adapt," he advises. Difficult to achieve with buildings piled brick upon brick, but almost DIY with a house that clips together.

Centralising production also allows for prototyping and testing in a way that is standard to product design but unheard of in domestic architecture. Mr McCarthy likes locating faults: "The process of finding a problem is good. Everything has problems: it's a case of understanding it and designing it out." The customer has an environment to live in that works as well as the car he or she drives.

And, like the car, it should be serviced regularly and come with a full owner's manual. "Housing will need to become more functional, adaptable and maintainable," says Mr McCarthy. Modularity - the ability to grow or shrink the space you live in - offers the prospect of a "house for life". Meanwhile, the increasing importance of surveys in the house-buying process shows that people want more information about the service history of a house. "That is of worth to somebody who takes the house off you."

Going modular and creating homes as mass products doesn't mean all houses will look the same. The ability to tailor a building to suit its occupant means variety, not uniformity. Moreover, there are different ways of delivering modularity. Research is still in early stages in this country and it looks as if flat-pack, frame-and-panel and volumetric interpretations will develop in parallel. And factory-produced, catalogue-bought houses will not be full of alien technology or even, necessarily, conspicuously modern. Richard Hodkinson says: "We're not involved in rocket science here. The innovation is the process."