Wood or Steel Frame?
Volumetric or Panelized Assembly?
Turnkey (fully kitted out) or just the bare-bones?
Offsite manufacture, or prefabrication of homes, offers up each of these decisions - and then some. The fact that there are no right or wrong answers and each option comes with both pro's and con's could partly explain why housing associations or local authorities are somewhat hesitant to make the move away from traditional brick-built construction.
As it happens, we've seen two opposite ends of the prefabrication spectrum over the last two days, and we're left with a lot of food for thought...
Offsite Homes (aka. Totally Modular) are a big operator based in Nuneaton. Their capacious factory manufactures volumetric components for residential buildings, schools and hospitals. The demonstration home, a high specification 2 bed semi/end-terrace, would've been transported to site in three separate steel modules, assembled and ready to let in less than a day. As with all prefabrication, sub-structure works would need to be carried out ahead of installation, however these could be planned to coincide with manufacturing the actual steel structures, saving time. The components were chosen for longevity, reducing unnecessary maintenance works across the buildings lifetime. No internal walls were weight bearing, so there would be a level of adaptability should the family grow and need more space.
Local Homes (standing for Low Carbon Living) are part of the Accord group, a Midlands based housing, health and social care provider. Their factory is modest but well designed, while the business is ran to ISO 9001 Quality certification. Timber frames are combined with weatherproofing, insulation, cladding and vapour permeable membranes (and windows where required) to make ready-to-assemble exterior panels that can be transported to site and erected in a number of days. A finished home takes a little longer, requiring the roof and internals to be finished, but understandably comes at a lower cost than fully furbished. The home is ready to be sold or rented between 9-12 weeks depending on construction type and offers similar prospects for adaptability.
I have no doubt that the controlled manufacturing environment for each of these products can result in a better quality home than traditionally built. I have no doubt that using semi-skilled local labour is more cost effective than employing reliable brick-layers and provides much more valuable social impact for the local community.
Still the housing sector as a whole uhms and ahhs - but the time to remain on the fence is diminishing as the gap in genuinely affordable housing is spiralling ever larger. On it's surface it seems like a matter of risk aversion, and nothing progressive or interesting happened as a result of that, did it?
Over the coming weeks we'll be costing up a few products from our portfolio in these alternative building styles and putting our thoughts together. If we can argue the RIGHT balance between risk and reward, I think there's every chance we'll be embarking on a prefab project very soon.