Why build offsite?

The simple answer to this question is, because the UK can’t achieve its construction volumes without using alternative methods of building.

Currently around 90%* of new homes in England and Wales are built using traditional masonry materials – brick and block. Much of the remaining 10% is timber frame with offsite manufacturing (OSM) having only a small slither of the pie. The story is a little different in the commercial sector where OSM is becoming standard practice for some large players and significant investments are being made into these processes.

So what have these developers realised which the rest of the industry is yet to discover?

Well firstly, OSM has some clear benefits over traditional methods of building – for example:

• Safer working conditions – factories provide far more predictable environments and with less workers on building sites, health and safety issues are greatly reduced
• Improved quality and standard of build – by building in a controlled factory environment, quality of workmanship can be more closely monitored and standards maintained
• Shorter and predictable build times – OSM is not impacted by the weather or by the availability of other trades, so timelines can be agreed and adhered to
• Fewer materials and deliveries to site – delivering modular units and panels to site requires far fewer journeys than traditional methods, meaning a reduction in noise, waste and general disruption.

Negative perceptions

Even when all of these benefits are considered, some people and organisations still have negative perceptions of the OSM processes – quite probably because they haven’t been given accurate information. One of the biggest problems is the terminology used: prefabricated units. This is what the Government and consumer media keep quoting when talking about tackling the UK’s housing shortage. Images which come to mind are of post-war accommodation, which had been built to last for only 10 years – this is simply not the case for 21^st century modern methods of construction.

It’s perhaps worth explaining here that there are two types of OSM – volumetric (modular) and panelised (or smart modular). Volumetric refers to entire units being built in factories and craned into place on site, whilst panelised refers to individual walls and floors being built at offsite facilities and then erected on site. Thanks to the development of BIM, both can be highly tailored in design and both are built to last – in the case of light gauge steel, in excess of 200 years.

Skills shortages

OSM also scores highly in addressing the issue of UK skills shortages – something which is getting steadily worse. The Federation of Master Builders’ State of Trade Survey Q4 2016 stated that of the 15 of the key trades it monitors, 40% showed skills shortages at their highest levels since 2013. The Government’s recent Housing White Paper acknowledged this and explained how provision for training was a priority. But while this investment is desperately needed, it’s not going solve the crisis in the immediate term, nor is it capable of taking complete responsibility for turning the sector around. More options are needed.

OSM doesn’t require the same level of availability of on-site skilled trades that building using traditional methods does. Only a handful of contractors are needed on site to erect the frames and while some specialist trades are still present, thanks to the considered design of panelised structures, that requirement is kept to a minimum.

In practice

The benefits of OSM can be realised across every type of construction project – student accommodation, residential, education, healthcare. For example, a light gauge steel system was used at The University of Derby’s new Cathedral Road student accommodation where a 350-bed, £14m seven storey structure was required for September 2016 intake. The contractor was originally heading down a traditional build route but time constraints simply didn’t allow. Using OSM, a 20-week build plan could slot in neatly and the development was completed two months ahead of schedule.

And at The Old Oak in Ealing, North London, seven storey and nine storey apartment buildings were built using OSM and positioned next to each other on a transfer platform. Weatherproofing was applied to specific floors of the structure to maximise the speed of build and enable other trades to maintain a good pace on site. The building was complete within 21 weeks and is believed to be the single largest steel structure of its kind in the UK.

The construction industry needs to change – Mark Farmer made that very clear in his review: ‘Modernise or Die’. Interest in OSM is growing amongst developers of all sizes and over the next 12 to 24 months I think we’ll see modern methods of construction becoming more and more commonplace on construction sites UK-wide.

 

Mike Fairey, Director, Fusion Building Systems

 
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