Prefab homes have suffered from a negative image but the latest designs are energy efficient and affordable, making them a much more attractive option. Nick Duxbury reports
Prefab. For many, the term - referring to homes ‘prefabricated’ offsite - will trigger memories of cheap, ugly, poor quality, temporary accommodation - a hangover from the post-war rush to house large numbers of people as quickly as possible. In the three years after World War II, around 156,000 prefab homes were erected. Many didn’t stand the test of time - even if the stigma attached to them has.
Sixty years later we have another housing shortage on our hands. The UK’s struggling economy has led building levels to fall to an all-time low with just over 100,000 homes built in England in 2010, the lowest in any peacetime year since 1923. Once again companies are offering prefab, or pre-modulated development as a possible solution. Only this time they are neither ugly nor poor quality. In fact, the companies building these offsite eco-homes are slashing wastage and costs and are promoting them on the back of their energy efficiency.
For example, UK company Future Form is marketing its ‘prefabulous’ Cub home, manufactured in Wellingborough, as an affordable eco-home. The white, cube building is built to level 5 of the code for sustainable homes. Since the government announced the ‘zero carbon’ definition, it effectively meets this criteria and the company claims it costs the same as a traditionally built affordable home - in this case starting from £1,200 per square foot for social landlords. A Cub home has been built at the BRE Innovation Park in Watford. It features an air source heat pump, super-insulated walls made out of 65 per cent recycled steel and standard fitted solar photovoltaic panels, reduces site waste by 90 per cent and can cut energy bill costs to just £56 a year.
Then there is the Swedish-influenced Spacehus, a timber frame home from Space Group designed specifically for the affordable housing market. For £80,000, the six-week process gets you a code level 4 house, while for an additional £10,000 this can be upgraded to a code level 5, zero carbon home through the installation of solar PV panels. Spacehus boasts high levels of airtightness and Space Group claims that it is so energy efficient it only costs £10 a week to run. This airtightness is the result of the house being built around the window in the factory, rather than the usual method of inserting windows into walls on a building site. There are other eco-benefits to the Spacehus and the offsite, pre-mod approach generally. ‘The waste in our industry is in the [construction] process,’ explains managing director, Rob Charlton. ‘There is absolutely no waste this way. No off-cuts or wasted bricks - at most, there is some packaging.’
Breaking the stigma
On paper, the Spacehus appears to be energy efficient, affordable and a way to help tackle fuel poverty - yet Mr Charlton is struggling to drum up interest. What’s going wrong? Partly the torrid housing market and partly shrugging off old assumptions about prefab.
‘There is possibly still a stigma around having a prefab house,’ he concedes. ‘We are trying to find out what the barriers are and what is keeping people from embracing it and instead continuing with a less efficient, more expensive method of building. People are scared of change.’
But not everyone is afraid of change. Some mainstream construction companies and landlords do seem to be embracing pre-mod again. For example, developer Keepmoat has entered the pre-mod market with a brand called Evolve (see box: Here’s one I made earlier). Its manufactured approach means that its homes have 43 per cent less embodied carbon - the energy used to make raw materials and transport them to building sites - than traditionally built homes. Properties are built to code level 4 as standard, but could be built to code level 5 to become zero carbon. Keepmoat also claims Evolve can be cheaper than traditional onsite construction methods.
‘It is really not what you might imagine from an offsite construction development’, says Ray Sanderson, head of sustainability at Frank Haslam Milan, Keepmoat’s development delivery arm. ‘There is a stigma [around the uniformity of pre-mod], but if you see our developments, you can’t see the difference between them and traditional builds.’
Here’s one I made earlier
Some housing associations are starting to show interest in what prefab can offer. For instance, 7,000-home Housing Hartlepool, part of the Vela Group, last year contracted Keepmoat to provide 68 Evolve homes at a development on Easington Road in Hartlepool.
In London, 26,000-home Notting Hill Housing teamed up with Skanska to develop the UK’s first ModernHus development in Brixton. The prefab scheme uses Scandinavian offsite techniques to provide homes they claim are 44 per cent more energy efficient than standard new build homes.
Similarly, 260-home, London-based Ducane Housing Association is working with contractor Apollo to add an additional storey onto two existing accommodation blocks in Hammersmith using 44 pre-modular housing units. In this case, the decision to take the pre-mod route was prompted by the need to minimise the construction time - but it will also achieve a ‘very good’ rating from the building research establishment environmental assessment method and will meet level 3 of the code for sustainable homes.