Since the publication of the Farmer Review in 2016, renewed emphasis has been placed on the role of off-site manufacturing. Here, Stuart Whiting, our Technical Director gives his opinion on the benefits of off-site construction and why he thinks the vast majority of the market remains reluctant to fully embrace prefabrication.
“Whilst the industry is beginning to embrace off-site manufacturing techniques such as Design for Manufacture and Assembly (DfMA), we are, unfortunately, still in the position where access and logistics are driving the use of these methods.
Many main contractors and end clients still feel that the potential increase in capital outlay and longer lead-in times is too big a barrier. Whilst there may be additional costs due to transportation, there are many advantages to taking work off-site: including the savings made from reduced time on site, increased quality control and reduced snagging.
Another key benefit is the role it plays in improving site safety. Embracing off-site methods will not only reduce the number of workers on site, but by pairing DfMA with a ‘just in time’ delivery approach for prefabricated components, off-site can contribute to a safer project – particularly desirable on highly congested sites.
Despite the benefits, adoption of these methods has been slow. Although it may cost more money initially, the long-term benefits of these measures can be significant; focus is often on the initial financial outlay of a project.
Yes, keeping work on-site may look like a cost effective option, but this will undoubtedly fail to take into account the additional costs that could arise from a delayed building schedule or a potentially poorly fabricated building component.
The Farmer Review has raised a lot of key issues in the construction sector; identifying traditional procurement methods, budget overspends and an adversarial mind-set as having a detrimental effect on the reputation of our industry. Taking as much work off-site as possible will ensure projects are delivered to the highest possible standards in the quickest timescale. As such, I believe organisations that fail to take a holistic approach to projects are doing themselves and the industry a disservice.
Our work on London Bridge is an excellent example of where off-site manufacturing has made a tangible difference to the outcome of a project.
The 6km platform at London Bridge station was segmented into 1,100 individual aluminium cassettes – all built within a specialised offsite manufacturing facility, which were then transported to site with a ‘just in time’ approach. Not only did this significantly reduce risk on site, but it allowed us to keep to the strict phased timescale for installation.
A number of projects that have adopted an offsite approach have had a BIM strategy in place from the outset.
Although BIM adoption remains at a relatively slow rate, the use of 3D and 4D modelling has enabled us to integrate more complex geometries within the design phase. 3D and 4D modelling has helped to push the envelope in terms of design by highlighting any potential challenges before components reach the prefabrication stage.
We have a number of projects which have an element of off-site manufacturing – with more in the pipeline. As a result, we have proactively invested in our two fabrication plants with the aim to develop further off-site solutions. We are also proud to be a member of the Offsite Management School, an initiative of leading contractors and specialists committed to helping their supply chains develop to meet the challenges we face as an industry by promoting off-site construction.
It’s clear there is a long way to go before off-site manufacturing methods are fully adopted by the industry. Although the end client must be the driver of change, we feel a responsibility to demonstrate to our clients the positive impact that off-site construction methods can have on individual projects. It’s a slow process, but one in which we are well placed to lead the way.”