At the end of last year the country’s biggest housebuilder, Wimpey Homes, joined forces with the Peabody Trust and manufacturer Britspace to build a pair of two-storey semis on a production line, erecting the prototypes outside Britspace’s factory in Gilberdyke, east Yorkshire. Their achievement is no longer unique, and it is one of the country’s smaller housebuilders that has followed their lead.
Sunley Estates has worked with building systems company The Elliott Group to factory-produce a four-bed detached house. And this time, the house has been erected in the middle of a conventional housebuilding site, where it will be lived in for trial purposes by a Sunley staff member, then sold to a pioneering housebuyer.
That’s not all. Within months a second set of modules will be arriving on the site for a second detached home, and a pair of semis are scheduled for manufacture. In fact, Elliott Group has a whole system for two and three storey homes, in detached, semi-detached, terraced, stepped or staggered form, called e.house. “We’ve looked at a lot of developers’ units and in 90% of cases they can be converted to modular construction, especially three and four-bed houses,” says Paul Smeeth, managing director of Elliott Group.
“We actually built and patented a volumetric house 25 years ago, clad in brick on site, but then we didn’t get any interest in it,” he says. Since then a lot has changed in housebuilding; homebuyers are demanding better quality, Sir John Egan has set an agenda for change for the construction industry, and traditional trade skills are much harder to come by. Sunley is feeling the effects of those skills shortages in implementing its standard procedure of getting five tenders from subcontractors. “Getting five bricklayers to quote is a job in itself,” says Tim Higginson, development manager with the company. “If we send out five enquiries, we get two responses.”
It is Higginson and his family who will soon be moving into the modular house, at Sunley’s flagship Port Regent site, on the marina at Sovereign Harbour in Eastbourne. The family will road test the house to see how well it delivers the anticipated benefits of a snag-free structure, lower heating bills and good acoustic performance. Sunley has already given it a guide selling price of £150 000, exactly the same as the asking price for the traditionally built version next door. Sunley sales and marketing director Anne Fendi believes that in spite of the unconventionality of the build method, the price is good value: “I feel it’s worth more than a traditional house, because it’s got so much more.”
Sunley chose to test modular housing at Port Regent where there was plenty of space for craning and delivery operations, and where build and performance could be measured against that of identical, conventionally-built homes.
The 345-unit site, custom-designed by architect FCS, contains nine house styles including a number of 1212 ft2 four-bedroom detached Magellans, the first modular testbed.
The exposed near-coastal location of the site provides a good test of both traditional and modular build techniques. A Magellan takes 20-24 weeks to build conventionally, but that is in good weather. The e.house modules, all shrink-wrapped, arrived at Port Regent before 8am on a wet and windy Saturday morning in December, and by six o’clock in the evening the modules were assembled and the build team were heading home. “We put the house up in the worst weather we could’ve had,” says Robin Bishop, technical executive with Sunley Estates.
The house is made of 12 modules, six for the ground floor and six for the first. The roof is made of three modules of felted and battened trusses, but tiled on site. The steel-framed modules are clad externally in a cementitious panel and finished in cut-down bricks to give a conventional exterior. Current variations in mortar colour will fade. Although the external walls are 50 mm slimmer than conventional cavity walls, the house has a SAP rating of 90, and external walls could have been packed with more mineral fibre insulation without increasing overall thickness.
There is additional height to the house, where the base of top floor modules are positioned on the lid of ground floor ones. The extra depth means stairs had to be redesigned, but on the plus side the first floor cavity is a practical services causeway, accessible by a series of trapdoors. “We could put all the latest technology into the houses,” says Elliott’s Smeeth. “Putting in more sockets, links for computers or a sound system is no extra work for us.”
Approximately 85% of the house is factory built. “We have used virtually all conventional materials here. It is how they are put together that is different,” says Smeeth. The next house to come off Elliott’s production line could have an even higher proportion of its build carried out off-site. It will be manufactured in just two modules per floor, which will produce fewer interfaces between modules, and have other benefits. “With fewer boxes we can replicate the internal layout of the traditionally built house more easily,” says Smeeth.
Although the next house is also a Magellan type, its design is more complex, with a bay window at ground floor level and a hipped roof. The pair of semis being lined up for future assembly will be clad in weatherboarding and brick.
The housebuilder has already learned from working with the manufacturer. “We were a bit sceptical about this to begin with, but we have got into it,” says Sunley’s Bishop. “It has made us look at things in a totally different way. Elliott’s way of carcassing the electrical wiring between the two floors is good - it means that you know exactly where everything is.”
For Elliott Group housebuilding poses few special challenges. “We do 36 000 lorry movements a year, so putting up modules is no problem for us,” says Smeeth. It is a highly successful company - it has just posted a profit of £9m on an £85m turnover - and it is taking housebuilding seriously. “It’s easy to do a plain house. What we have to do now is keep up the momentum. What we want from customers is for the design to be frozen and not change, then we will build it within six weeks - a week to place the orders with suppliers, one to two weeks for suppliers to deliver, and then three weeks on the shopfloor.” It’s that simple. Now all housebuilders have to do is sell it to the consumer.
Source
Building Homes
