A worrying site

I am a keen advocate of off-site manufacture because it increases certainty and quality in an industry that does not enjoy a good reputation among clients for either. However, I am beginning to have my doubts that it is not being given the support and investment that will enable it to add real value to the building process.

There are many shining examples of the use of pre-assembled construction in the UK. Sadly, they tend to be projects where the industry had little choice but to embrace the concept, such as the Terminal 5 project at Heathrow Airport where more than 60% of services will be assembled off site.

The need to minimise work on a very congested site was the reason off-site was chosen here. Using pre-assembly has enabled the contractor to occupy less than half the area labour normally requires.

But the approach will reap rewards in other ways, including better quality because components are assembled in clean and efficient factories; a construction period cut by six months; a high degree of standardisation of components; and better safety.

Yet, despite the obvious benefits of off-site manufacture, designers never seem to fight its corner. Talk to them and they claim it’s a great idea. In practice they rarely manage to put the case to architects, who will need to be persuaded to rethink design elements – locating vertical service risers on the outside of a service core so prefabricated riser-sections can be easily installed, for example. Nor do designers seem to argue off-site’s financial benefits convincingly in discussions with quantity surveyors.

Designers aren’t the only thorn – contractors with experience and expertise in off-site fabrication are also few and far between. Although most accept that factory conditions produce the best quality installations, few are willing to invest in the production facilities to pre-assemble components. I know of no more than about 10 contractor organisations with the ability to manufacture significant numbers of modules off-site – hardly sufficient capacity to drive innovation through competition.

Heavyweight companies such as Lend Lease and Laing must be less conservative about innovative technologies

Other industries have got stuck into using cutting-edge technology. I recently visited BAE Systems’ design centre in Barrow, Cumbria, where it manufactures ships. BAE has made impressive investments in computer modelling – and that’s leading to improvements due to less reworking and a better ability to incorporate late design changes. Likewise, aircraft manufacturers Boeing and Airbus are developing supply chains that work in a computer-generated “single project environment” to enable large components to be made independently in remote manufacturing centres, safe in the knowledge they will be compatible with the main assembly.

Comparison with these industries may be disingenuous. The process of ship assembly is surprisingly basic compared with standards achieved in the construction industry, while the aerospace sector attracts massive investment, much from government. But the UK construction industry does boast heavyweight international companies, such as Lend Lease, Laing O’Rourke and Skanska. And these firms need to be less conservative in their approach to innovative technologies.

In fact the entire construction industry, including architects, engineers, cost consultants and construction clients, needs to work harder to promote off-site. Bringing design and manufacturing teams together earlier in the design process, and investing significantly in 3D modelling tools, are some of the things they should be doing.

If they don’t the consequences will be dire: clients will start to think twice before taking on UK building projects. Or worse, overseas contractors could take another bite out of a weaker UK construction market – all because we won’t take the need to improve efficiency and standards seriously.