The government has renewed support for offsite manufacture in a bid to ‘revolutionise’ housebuilding
Last week housing minister Mark Prisk confirmed he would set up a working group to promote housing assembly from large, factory-made components. The move comes almost a decade after John Prescott’s failed attempt to boost housing supply with a wave of £60,000 quick-to-build homes (AJ 09.08.05).
Aimed at reducing costs and improving speed and carbon efficiency, the prefab drive is the latest attempt to solve a deepening housing crisis, which saw fewer than 100,000 homes started in 2012.
It comes as major house builders including Barratt and Taylor Wimpey announced doubled profits, despite the industry’s failure to supply enough homes.
The focus will be on private rented, self-build and affordable housing and the working group will look at how to tempt investment into the sector and create market conditions which boost confidence in the method.
Prisk’s statement followed the submission of a government-commissioned Construction Industry Council (CIC) report on promoting offsite construction.
This called for new manufacturing facilities, tax incentives, a more stable regulatory framework, the release of ‘oven ready’ public plots and a new Institute for Future Housing Research.
CIC review participant Rab Bennetts of Bennetts Associates insisted mass production could boost environmental and space standards.
He said: ‘When you look at offsite solutions like Rational House in Hammersmith, you get a higher quality than you get elsewhere at the moment.’
Welcoming the announcement, Ben de Waal of AECOM – architect of the council-backed Rational House flat-pack scheme – suggested future grant regimes should be tied to local authorities and registered providers adopting offsite construction.
But Amin Taha of Amin Taha Architects, who took part in the European EMVS/ManuBuild prefab housing contest in 2006 was sceptical, condemning ‘part complete box housing craned and stacked from a lorry’ as ‘dated’ and ‘economically naïve’.
He said: ‘Since private house builders sell at market rates, landowners will swallow construction savings to leave developers with the expected profit margin. The end result is faster construction, higher profits, but not cheaper purchase prices.’
Design for Homes’ David Birkbeck said: ‘Prefab works well if you have extensive repetition. But we don’t do repetition in the UK because the country is made of oddly shaped pieces of land requiring sensitive responses. Whole house solutions have been talked about for 15 years but we have yet to see a successful example that has broken out from the niche.’
Hal Currey, Arup Associates
Off-site manufacturing offers clear benefits in terms of delivery, standards of construction, safer working environments and presumably cost. It is important that design isn’t side-lined – architects have a key role to work with manufacturers to develop housing typologies. These typologies need to be appropriate for the manufacturing process while addressing the concerns of the consumer – as recently highlighted by studies such as the RIBA’s Case for Space.
Tony Hutchinson, Capita Symonds
Introducing new techniques into UK housebuilding would be very welcome if it can deliver quality and quantity consistently. We are all familiar with the negative aspects of mass produced system built housing. It does seem to be logical that building homes from larger component parts that have been produced under factory conditions will generate savings in time and cost. Well done this is true but the challenge appears to lie in scaling up volumes to achieve the anticipated savings whilst maintaining the attention to detail necessary to sustain quality standards.
To deliver a consistent quality using modular construction means that all elements of the process need to operate within much finer tolerances so that engineered units fit together every time. It is a much less forgiving process than traditional methods which have more scope for accommodating variations. This applies to all parts of the construction process, from ground works upwards.
Equally there is a stigma attached to “prefabs” or system building, suggesting a second class product, designed for a shorter life than masonry. Yet at the same time bespoke manufactured properties attract a premium. The salutary lessons of timber framing in the 1980’s with the rushed introduction of a new technology leading to shock headlines, or more recently anxieties about fire transmission through cavities in timber panels need not only to be learned the industry needs to demonstrate how the problems have been overcome.
Will there be an effective demand for homes built using new technologies, arguably there is as there are successful projects in many parts of the country. There has to be a concern that innovation equals novelty equals unproven equals risk. Mass market modular or system built properties will be discounted because the costs are lower then discounted again by mortgagees because they will anxious that on a forced sale the value will be less than a comparable traditionally built property.
In terms of running costs modern methods of construction, however delivered can offer impressive reductions in energy bills. Maintenance and repair of such properties may be more complex and costly. Energy efficiency and weather tightness can be compromised by puncturing the membranes within panels, adding kitchen units or shelves can depend on locating the structural components to carry the loads, adding sockets can leave gaps for smoke and flame to pass through fire retarding components.
All these problems issues, risks and questions need to be articulated, considered and resolved. A thoughtful debate that does this is to be welcomed. Rapid introduction of new technologies driven by financial incentives risk repeating Ronan Point and the scandals of the 60’s and 70’s. Perhaps the best analogy is to look at the motor industry, innovations tend to be introduced first into premium products and gradually as the technology is proven and better understood it is introduced into lower priced models. The reverse process seems to apply to housing, a new technology can save money so it goes from prototype to high volume production with inadequate attention to planning production, designing new processes and upskilling the labour force.
Yes it needs to be done but thoughtfully, carefully and with the complete production, construction, sales and post occupation cycle taken into account.”
Nick Willson, Nick Willson Architects
We are working on a pre-fabricated roof top addition. This will be constructed using large timber panels, or sections of the addition and craned up onto the roof. I have attached a few simple images.
I think that pre fabrication or off site manufacturing is already being used quite a lot for tight sites, where access is restricted and a large number or pre formed panels can be lifted by crane, also for projects where build time is to be fast, schools for example can benefit from pre fabrication as lots can be built off site and then brought to site.
For houses, I think that the target of code 6 or zero carbon for 2016 etc may help push the use of pre-fabricated timber framed buildings being used more, the advantages of having an accurate highly insulated envelope with penetrations for services already cut appeals, Also advances in timber structure also allow for more flexibility. Our Flint house used a timber frame from Kingspan and the frame and walls went up in two weeks. However, we did have some reservations form the insurance companies as the house was not made of a masonry construction.
Philip Bintliff, Studio Baad
One problem with government initiatives such as that is it perpetuates a ‘paternalistic’ impression where government gives and citizens receive. Housing is seen in a way like the National Health Service was when it was invented - a true public good provided with the best of motives. But look at it now when it’s morphed into a commercial enterprise.
I think the government shouldn’t be spoon-feeding the public with housing but empowering the nation with a programme of self-help. Self-build housing can be built to the highest standards but more importantly will be better looked after by its creators.
Our design for our £35,000 Hut was a kind of 21st century pre-fab - self-built, off-grid so it’s not at the mercy of grasping utility companies - it could be disposable or it could be loved for life.
The £100 million spent on the explore venue could have built more than 3,000 two-bed Huts - with all the training, educational and financial trickle down benefits for the economy - let alone the empowerment of a generation of those disenfranchised by a neglectful, self-serving financial sector.
Paul Simms, Make
The government has announced a new working group to incentivise off-site house building Do you think this could solve the housing crisis?
In the long term off-site manufacture could help to increase volumes of housing schemes being built each year and already buildings and building components are increasingly being manufactured off site in different states of pre-assembly. However I don’t think this will solve the crisis in the short term. There is a learning curve associated with off-site manufacture which will have its own price tag and in truth; there is currently a shortage of firms who have the necessary skills and resources to deliver large volumes of prefabricated buildings.
However, what is interesting is that the process of offsite manufacture is much closer to the way that buildings are designed and detailed in the digital age. CAD and BIM enable us to design and visualise buildings which can then be ‘printed’ in three dimensions in the factory, so both design and construction sides of the built environment industry are moving towards this approach.
Has the design of off-site housing improved significantly to make large scale roll out feasible?
The number of projects that are successfully being built using off-site manufacture techniques is growing, which illustrates that large scale roll out is feasible. Already competition is growing between modular building firms which is driving quality and efficiency up. In fact in our experience, techniques and quality are improving such a degree that it is sometimes very difficult to tell a traditionally built building from one which has had some form of prefabrication and as such there is a growing social acceptance of living in a pre-fabricated housing scheme.
However it is important for all parties - from the developer to the purchaser - to understand that off site manufacture does not necessarily mean that our future homes have to look identical in order to get the economies of scale of mass production. Whilst, repetitive design works well in large developments, where repetition can maximise the character of the building, individual dwellings need more care and attention to detail to distinguish them from the next home.
The danger is that affordable and private rent housing could lead to a proliferation of repetitive homes with little character. As such, clever design is required to ensure that waste is minimised, that production volumes increase and that the highest design quality is still delivered in the end product. Certainly, at present, it is easier to add character to large scale buildings, where the overall building appearance and feel gives it originality and character.
Do mortgage providers and insurers support the model?
A large number of projects are already funded that use these techniques. They have been supporting timber frame construction for decades. The process of off-site manufacture makes it easier for investors and banks to monitor progress and quality.
Furthermore, targets for reduction of C02 emissions will require more innovation and new techniques for construction, so it is inevitable that the banks attitude towards modern methods of construction will have to evolve with advances in the technology.
But, there are many risks associated with this form of procurement. For example, if the contractor goes bust, you could be left with hundreds of partially-finished buildings sitting in factories.
Are you surprised the government is supporting off-site housing when it had failed and been rejected in the past?
In reality, the antiquated methods of traditional brick built housing is unlikely to deliver the volume of housing required at the same time as meeting targets set by the Code for Sustainable Homes. It is therefore not surprising that the government is now supporting off site manufacture. I expect this to increase – certainly, there is a growing public acceptance of timber frame, steel frame and other prefabricated building forms. This is because people are starting to realise that more of the buildings around them are being built this way.
I expect more developers to start to champion off site manufacture as they realise the economies of scale that can be achieved for larger projects with lots of repetition. For country-wide projects on this scale, the savings should be even easier to realise.
Government primes prefab for housing crisis fight