Brave new homes

The Housing Corporation echoed Ford's philosophy last month when it announced its accreditation process for standard housing templates. The argument goes that it is hugely inefficient for social housing providers across the UK to produce bespoke designs, all of which have to be approved by the corporation. The corporation believes that standardising components, layouts and manufacturing processes will save money.

Off-site housing manufacturers have already responded to this initiative and produced a range of standard templates. Volumetric manufacturer Yorkon has had three designs approved, as has Advance Housing. But Space4, a subsidiary of housebuilder Westbury and the UK's largest producer of prefabricated housing, has thrown its hat into the ring with 17 housing templates, which it hopes strike a balance between choice and efficiency.

Housing associations are not compelled to use the corporation's standard templates, but if they do, approvals may speed up and costs come down, making it difficult for cost-conscious associations to resist standardisation.

"I believe it will reduce costs, as there is too much reinventing the wheel each time in terms of design," says Brendan Ritchie, innovations director of social housing contractor Willmott Dixon. "Anything that creates more volume will help the manufacturers cut costs."

Ritchie points out the templates only apply to interiors, meaning homes won't end up looking the same.

Space4 sees standard templates as a way of making homes cheaper. "We commissioned a range of housing templates incorporating Housing Corporation design standards," explains managing director Patrick Dorman. "These were designed to be [Housing Corporation] compliant but also to support optimum efficiencies. In other words, to make them as simple as possible for our manufacturing process and therefore more economical for our customers."

The firm worked with social housing architect Calford Seadon on the 17 accredited housetypes.

The factory can make 6000 timber-framed four-bedroom houses a year. Of these, 2000-2500 are earmarked for Westbury. But to make a profit, the factory needs buyers for its remaining capacity, and social housing providers are important customers.

"We are a high-volume producer," says Dorman. "Our profitability is totally governed by volume. We expect to be in a break-even position this year [by March 2004] so we need the running rate in the second half of the year to achieve that."

Space4 produces a panellised whole house solution (see "How Space4 builds a home, overleaf). The factory's flowline production process has been designed to be highly efficient yet very flexible. The computer-controlled line can produce different housetypes in any sequence. Fundamental changes to the homes' specification – for example, changes dictated by new building regulations – are accommodated in "a matter of hours", according to Dorman.

The 17 templates were designed to suit the factory's overall manufacturing process. The key is to juggle the wall configurations of individual homes to fit the company's standard production unit, called the multiwall. The factory has been configured to produce multiwall panels 12 m long. These are then cut to the right length at the end of the line.

This is comparable to calculating how to cut up a sheet of standard-sized mdf into the maximum number of useable pieces. At Space4, any offcuts can be made into new panels, but the social housing templates have nevertheless been designed to get the most possible out of each multiwall. According to Dorman, the utilisation rate for each multiwall is 85% for homes that have not been designed for manufacture, but 90% for the social housing templates.

A second way of improving efficiency is making the houses faster to build once they reach site. As Space4 also erects every home it makes, it has identified ways of making the corporation-standard housetypes quicker to build. For example, each floor is made up of several floor cassettes. "It's more efficient to have as few cassettes as possible," explains Dorman. "You can save 15 minutes on site by having one cassette fewer." This may not sound like much, but when you consider you build a house in a day, it's quite a lot."

The bathrooms, cloakrooms and stairs have been standardised, too. "This proposes an opportunity for a pod and panel concept for bathroom fit-out if there is sufficient demand," says Dorman, adding that a second plant for standardised pods is a distinct possibility.

However, he emphasises that Space4 hopes it has struck a balance between standardisation and individuality. "We have made sure these are not inefficient houses, but we have not gone to the utopian efficiency of a grid that is so inflexible that our customers wouldn't want them."

Willmott Dixon's Ritchie has also spotted the potential of standardised templates. The company sources some homes from Fusion, which makes a panellised product similar to Space4's, albeit metal-framed. "If you are standardising the room layouts it's logical to standardise the services," he says. "You know where the plumbing and electrics go so there is the potential for fully enclosed walls with services already installed. Currently that can't happen as the decisions aren't taken early enough in the process."

Dorman believes off-site manufacture will ultimately be cheaper than traditional construction, although in common with most homes built off-site, Space4 products are marginally more expensive in construction terms. "There is a favourable cost trajectory [with off-site ] when you consider ongoing legislation and contractors' inflation rates," he says. "Sure, we will have to add more materials to meet future regulations, but this will be cheaper than the conventional alternatives."

Ford's vision of a mass-produced future for cars is slowly becoming true for homes.