PreFabs Sprouting

The UK's construction industry doesn't have a reputation of dealing well with change. It's an industry which is riddled with stereotypes of Sun-reading, backside-bearing, wolf-whistling men who don't take the most amount of care over their jobs. Clearly as with all sterotypes, these aren't fair or accurate descriptions of the industry as a whole. However asking builders to embrace new things like site safety or energy efficiency has been a battle in years past. Now the industry is on the cusp of one of the biggest game-changing revolutions in its recent history; prefabrication.

I know, I know - prefabs have been around for decades. A tour round some of the towns and cities which bore the brunt of bombs dropping during the Second World War will tell you that. Life is cyclacle however. After the war, Britain faced a huge housing crisis. Thousands of people had lost their homes and the Government had to kick start a house building campaign which hasn't been replicated since. The UK is now, we are repeatedly told, again in the grips of a housing crisis where there aren't enough houses to cope with population growth and the houses which are being built are too expensive for people aged under 40 to buy. Successive Governments have pledged to build hundreds of thousands of new homes, only to fall short of their own optimistic targets. Since the 1970s the country has built an average of 160,000 new homes per year. The current Government has reiterated the need for 275,000+ new homes to be built to cope with demand.

Currently, the number of housing completions is 66% of the number of granted planning permissions for new homes*. For a variety of reasons, not all the houses which are granted planning permission ever get from a piece of paper to bricks and mortar. 60% of new homes are built by 10 companies in the UK* at present and so if those 10 companies don't build to their potential, then numbers stall. Something has to give in order for houses to be available and then affordable for 'average' UK residents to be able to buy and many people are seeing prefabrication as one of the solutions to these problems.

Prefabrication can mean different things to different people. There are types of prefab which start at Huf-haus style builds, through to modular pods which are built off site and then assembled round a concrete or steel frame. When compared with traditional builds, any of these options are widely acknowledged at giving both clients and builders some significant advantages.

Houses can be built much quicker as the structure can be assembled in a factory whilst the groundworks are completed. Once the site is ready, then the prefab can be delivered. Speed of build is clearly currently a major hurdle to getting anywhere near the target of 300,000 new homes per year. The prefab process can also (depending on the method used) overcome adverse weather conditions which may cause a site to have to stop work, particularly for cold weather affecting brick and block laying.

Arguably they are built to a higher standard in a factory because of the quality control checks which are available in a sterile factory environment, versus being buffeted by wind and rain on a weather-beaten site outside. The repetitive assembly in a controlled environment also leads to fewer mistakes being made the manufacturers would argue.

From both a cost and environmental perspective, there is less waste during construction with prefabs, as quantities of materials can be more precisely calculated and ordered. There's also a lower likelihood of damage occurring than on a traditional site, either by people, plant or precipitation.

All of this sounds very exciting for the future of housing. Lower prices, more availability, better environmentally; the benefits seem unarguable. However, the rewards need to be balanced against the risks. The main material in any of these construction types is wood, so particular attention needs to be given to fire risk mitigation for both the construction site and finished article. If building regulations are changed to bring in a greater level of thermal performance, it will be harder to achieve required levels of insulation without using highly combustible products, or using greater quantities of mineral/glass fibre which will then in turn increase the material costs and footprint of the buildings. There is also a possibility that the industry will continue to lose skilled labour such as bricklayers if more alternative facade materials and construction methods are used. In a market where brickies are already in short supply versus 10 years ago, the cost of laying is increasing rapidly due to supply and demand. Increased labour costs and a decreasing skills base is not where construction needs to be.

The evidence now is irrefutable though - prefabrication is here to stay in construction and not just for traditional housing. High rise apartments are being built now using off site construction methods, and companies such as Premier Inn have also embraced this method of building. Just as more and more companies are seeing the advantages of building with clay block systems such as Porotherm which gives the speed of timber frame but with the benefits of masonry, prefabrication is providing flexible solutions which are appealing to clients and builders. Traditional construction won't die but it will have to adapt to a changing market.

The 21st century is challenging so many industries in so many ways; we truly are living in interesting times. Just like with the digital revolution, if firms involved in construction don't respond to these market distruptors they will struggle to compete and survive in the medium to long term. Builder's merchants, material manufacturers, builders and architects all need to understand how they will fit into this brave new world. One thing is for certain though; if prefabs continue to become mainstream we can say with confidence that we will end the housing crisis and that can only be good for everyone.

* Statistics taken from 2017 Government White Paper 'Fixing our broken housing market'

Image Credits: Prefab houses in Birmingham courtesy of Wikipedia. Modular capsule courtesy of Elements Europe