Last year, some housebuilders came to the conclusion that prefab was the future and started gearing up to meet it. Now many of the claims for factory housing are looking increasingly shaky.
As rumours of factory closures go, it was hardly in the same league as the Ford plant at Dagenham, or Corus' huge steel mill at Llanwern. But speculation that Persimmon is considering shutting Beazer's Torwood factory in Ipswich has the housing world buzzing.

The £10m plant, which opened in January, was essential to Beazer's ambition to industrialise its housing output. The plan was to use the prefabricated floor cassettes and wall panels made at Ipswich, and a second Torwood factory near Edinburgh, in 40% of the houses it built this year. The company was aiming to open a third factory, and one of the aims of its abortive merger with Bryant was to become the UK's leader in prefab housing.

But Persimmon is sceptical of prefabrication – chairman John White has said he believes that his customers prefer brick and block. And this reluctance to embrace prefabrication comes at a time when many housebuilders are suspecting that factory production is not the miracle cure that it appeared to be. "A lot of the attempts at prefabrication have not found the pot of gold at the end of the rainbow," says Fran Nowak, senior housing consultant at research body BRE.

A year ago, the ultratraditional housing industry was stampeded into experimenting with innovative production methods. The starting gun was fired by the Peabody Trust's Murray Grove apartment block in east London, the first multistorey, housing project in the UK to be entirely factory-built. In the space of a few months, Wimpey announced that it was to trial steel-frame housing at Romford in Essex, Westbury unveiled plans for a £15m timber-frame factory in the West Midlands, and Beazer started work on its Ipswich plant. Commenting on these developments in January 2000, Hugh Pearman, The Sunday Times' architecture critic, proclaimed: "Modular housing is back in style." The case for prefab seemed utopian: it promised shorter construction times, cheaper build costs and an end to skills shortages, while higher tolerances would satisfy increasingly demanding consumers and new technologies would enable builders to meet stricter Building Regulations.

Now the prefab pioneers have come up against unforeseen snags. Wimpey's Romford experiment, for example, is still not on site after planners kicked up a fuss. Wimpey regional director Tony Clipstone says the firm is still evaluating steel frame, along with other systems; any decision on whether prefabrication is worthwhile, he says, is "a long way off".

Problems, problems
A clue to why this might be is given by BRE, which says that initial results indicate that many systems are falling short of expectations. Nowak has been studying the efficiency of housing innovations such as new-generation timber and steel frames and panel-based systems, using a process-monitoring system called Calibre.

"We discovered that constantly developing a new shell was only tackling one-third of the problem," says Nowak. "The real issue was the plumbing, the electrics and so on, which represent at least two-thirds of the work." Nowak found that skill-hungry and expensive activities such as plastering, plumbing and carpentry were taking far more than the three visits that had been anticipated, offsetting the time and money saved in erecting the shell. "In practice, there can be up to 11 visits per trade," says Nowak. "Even though they've invented a new shell, they haven't tackled the finish, fit-out and services – and it shows." According to Nowak, volumetric production is the only method that addresses this problem. Volumetric construction – used to build Murray Grove – involves building fully-fitted and finished modules in a factory. These are transported to site and stacked one on top of the other. This means that the need for skilled tradespersons on site is eliminated, and that units can be erected as fast as the factory can churn them out.

However, volumetric production is throwing up another set of problems. First, units have to be designed to fit on lorries rather than to suit occupants. Transportation is inefficient, as hauliers drag large empty boxes around the country. Second, unlike frame systems, which tend to be disguised by brick cladding, volumetric units do not look like traditional homes. "They're having problems with the finishes," says Nowak. "They're finding it difficult to make them look like it's going to last 70 years." This may sound trivial, but it is leading to concerns that mortgage providers will refuse to lend against them.

Volumetric production tends to be more expensive than traditional construction – at least while the limited uptake of the technology is preventing economies of scale from developing. The £2.3m Murray Grove worked out 5% more expensive than a conventional building.

It took other countries 20-30 years of development and improvement to get market penetration

David Gann, SPRU

However, Murray Grove, designed by Cartwright Pickard Architects, was a runaway success in many other respects, and is widely regarded as having turned around housebuilders' attitudes to prefabrication. Tenants are delighted with their homes; no defects have been reported and no maintenance was required in the first six months.

"Originally we were particularly interested in getting benefits of cost," says Dickon Robinson, development director at Peabody Trust. "We've since realised that the quality benefits are even greater." But large housebuilders have yet to copy Murray Grove's success. Of the handful of volumetric projects in progress, most are for student and nursing accommodation and social housing. This hints at another emerging problem: factory-built housing is still regarded by some as a downmarket product – and it is rumoured that Persimmon's reluctance to take on Torwood is because it plans to cut its output of affordable houses and go upmarket. High-margin executive homes are tied to traditional materials and construction methods. "I don't think they believe in the concept of off-site fabrication," says one City analyst who follows the sector.

David Birkbeck, director of Architects in Housing, argues that housebuilders investing in new techniques have no intention of entirely replacing traditional build. "It is being introduced as a percentage of total output, to take some pressure off the skills crisis. Prefab has been earmarked as a way of taking pressure off good subcontractors so they can concentrate on building the most expensive houses." But given that increased build quality is the main reported benefit of factory units, this approach seems counter-intuitive.

Teething problems are inevitable with prefab, Birkbeck adds, as it involves introducing new working practices all the way down the supply chain. Firms will cease to be construction outfits and become manufacturing and assembly concerns. Logistics and quality – not among the industry's strong points – are of paramount importance.

A question of discipline
"The industry is not used to meeting factory production line disciplines," agrees Peabody Trust's Robinson. "On a site, if something's delivered a week late it doesn't matter much. But in a factory, it would throw the whole production schedule out. I imagine there will be a fair amount of squealing in the supply chain when they realise there's an enormous pressure to deliver things on time and to extremely high quality thresholds." Some firms are already finding this out for themselves. "We found the supply chain very slow to react," says Clive Wilding, managing director of Gleeson Homes, which is developing a timber-frame system. "There's been a reluctance to move on as quickly as we'd like them to." There are also signs that prefabrication will not end the skills crisis but will instead create demand for new types of workers. "At the end of the day, you still require qualified people to put these things together on site – and they still need training," says Keith Blanshard, director and general manager of Yorkon, the firm that built the modules for Murray Grove. And high-tech homes still need skilled trades. Yorkon employs 800 people at its Huntingdon factory, many of them in skilled trades such as joinery, painting and plumbing, and many of them poached from the construction industry. Blanshard says the people-hours involved in volumetric construction are less – "but not significantly".

Proponents argue that what we are witnessing is merely the first stage in a wider, Egan-inspired drive to transform housebuilding. "No one said putting a timber frame up was going to solve all the problems, says Professor David Gann, of the University of Sussex's Science Policy Reseach Unit: "It took other countries 20-30 years of continuous development and improvement to get market penetration." Those sticking to their prefab guns include Westbury, which opens its £15m Space4 factory at Castle Bromwich in the West Midlands next month.

The plant, which employs 120 skilled and unskilled workers, will produce "fourth-generation" timber-frame homes that will eventually supply the firm's entire annual output of 6000 homes. Westbury has teamed up with the Construction Industry Training Board to train assembly teams, although much of the fit-out and finishing work, including the brick cladding, will be done by traditional contractors.

What’s holding up the prefab revolution?

The market is fractured
Predictions of thousands of identical new homes rolling off production lines like cars are misguided. Homes vary widely, even within short distances, because of geography, local traditions and planning idiosyncrasies. Coupled with the large number of relatively small housebuilders, this makes economies of scale hard to achieve. On top of this, much of the demand for volumetric housing is from tight inner-city sites, where a bespoke product is often required. Orders are uneconomic
Manufacturers want to process large orders. They are reluctant to indulge housebuilders’ small-scale experiments with new technologies unless they see a strong likelihood of future business. “For us as a medium-sized builder it’s more of a challenge,” says Gleeson managing director Clive Wilding. “We can’t say, ‘Can we have 10,000 bathroom pods?’” Many housebuilders have been forced to invest in their own production facilities to get round this problem – if they can afford it. Consumers are not trusted
There is no evidence that homebuyers are suspicious of prefab – but still builders are taking no chances. High-tech shells are being disguised behind traditional – and labour intensive – cladding. Homes built at Space4, Westbury’s £15m timber-frame factory at Castle Bromwich in the West Midlands that is due to start production next month, will feature hand-laid brickwork “for marketing and public perception reasons”. City opinion is sceptical
Social housing providers such as the Peabody Trust are able to borrow against their substantial property assets to fund experimental projects. But housebuilders’ low stock market ratings and poor liquidity mean they do not have access to capital to invest in new technologies, and analysts – who have immense power over investors’ decisions – question the logic of firms diversifying from their core skills to set up and run sophisticated production facilities. “Just because you’re a good housebuilder doesn’t mean you’re good at running a factory,” says one. Housebuilders are conservative
As a handful of firms steam ahead with initiatives, the others watch from the sidelines to see how they get on. “They’re thinking, ‘Let the first guy spend and lose the money,’” says Fran Nowak, senior housing consultant at BRE. “The problem with being first is you’re not going to get savings right away.” On top of this, there are reports of traditional builders using scaremongering tactics to discourage customers from buying factory-built products. “I’ve met sales teams who can’t tell you what the letters NHBC stand for, but can volunteer their concerns about interstitial condensation in the timber-frame houses next door,” says David Birkbeck, director of Architects in Housing. Planners are planners
Romford council forced Wimpey to ditch plans to use lightweight granite-effect roof tiles on an experimental development of steel-frame houses, claiming they would weather more slowly than traditional roofs nearby. Instead, they insisted on a costlier and heavier Welsh-slate-effect tile that required a skilled roofer to instal. “The whole Egan initiative would unravel if every planner took that approach,” says Birkbeck. Wimpey is appealing the decision. Building Regulations are inconsistent
The proposed amendments to the energy regulations in Part L looked set to boost thermally efficient prefab systems – until the revised noise regulations of Part E came along. Part E favours traditional heavy blockwork and wet plaster. “You’re back to the stone age again,” says Gleesons’ Wilding, which is developing a timber frame system. “That set progress back a bit. I beseech the government to show some joined-up thinking on the issues.”

Here’s something we made earlier – 21st-century prefab in the UK

Volumetric construction has carved a niche in affordable housing schemes such as this Caspar project in the centre of Leeds, but is meeting resistance in the private housing market.

Many companies are experimenting with panel-and-frame systems – the house above is a steel frame home by Wimpey. But planners have objected and the firm says a decision on investment is “a long way off”.

Beazer opened an English factory last month to make components for its timber-frame system, including the wall-panels pictured above. Persimmon’s takeover of the firm, however, has thrown the initiative into doubt.