Do You Need Specialist Partners in Offsite Construction?

Lewisham Exchange

20 years ago, I gave my most unpopular talk. At an event promoting offsite construction shortly after the publication of the Egan report, I somewhat rained on the parade by stating that it would never take off unless one or both of two things happened. Either the Government should make it mandatory or there wasn’t enough skilled labour to build ‘on-site’. In general, people have massively underestimated the benefits of not having a factory, sending materials directly to where they’re finally used and only employing workers when they’re needed. Add to that the misplaced notion that main contractors would delight in their supply chains making no mistakes whatsoever, offsite-construction was really up against it. A previous business of mine was a specialist rollformer and I set up company that supplied modular and unitised solutions. We were very excited about it and we had many innovations, but like many others, I closed it due to well-meaning clients procrastinating so long that we couldn’t support the factory. I was a private business and not prepared to lose money. It was crushingly disappointing as anybody will know who has had to look people in the eye and tell them they have lost their jobs. Despite this experience, it’s time to try again. We are established players in the load bearing light gauge steel market and building envelope experts. We have just announced an investment in a new framing line and are setting up a new factory to assemble frames. Why? Because something feels different this time.

The inevitability of labour shortages

The labour shortage needs to be allowed to play out. This is what offsite construction has been waiting for 20 years. There is enormous latent capacity within the industry. It’s been a constant source of surprise and disappointment to me that we haven’t had more approaches from housebuilders about the supply of 2D and 3D frames. We’ve been making pre-assembled frames for flat-to-pitch conversions for 30 years. The chronic shortage of labour I think is now possibly irreversible and it’s reminiscent of what happened about 20 years ago with blockwork infill walling. The lasting legacy of our failed offsite enterprise was a successful SFS business. SFS initially struggled to gain traction for the infilling of frame bays. It was faster and tidier but there was no lack of blockwork installers and building control inspectors were unfamiliar with it, demanding calculation packs for every job. They stopped doing that over time and as the popularity grew, fewer blockwork installers became available and very quickly SFS became the standard method. In about five years there was a complete turnaround and it will never go back.

Lewisham Exchange
Lewisham Exchange in London, 35 & 20 storey residential towers, built 2020/21 using 3D structural modules by Vision Modular, clad with unitised Mechslip brick cladding panels, completed in under 18 months.

The same thing looks set to happen with brickwork. If people can see the emergence of quality brick slip systems, why would they spend their apprenticeship training for what might be a dying art? We began developing our brick slip system about five years ago. As a super-critical person myself, I didn’t want anything that could be accused of being ‘fake’. I wanted a modern interpretation of the use of clay as a robust, durable cladding material. When developing all our systems, we always have offsite-compatibility in mind. We have lots of firm ideas about what a successful offsite construction company should do and I think you can spot those who will fail very predictably.

For example, our envelope business has shown us that it’s not necessary to standardise the componentry. When a building is surveyed, what looks like 500 identical cladding panels can often end up being 500 unique panels with just a few mm of variation. The key is to have a process that can cater for this – usually a digital order-processing and manufacturing environment. Each one of our cladding systems has up to 100 pages of internal design guide documentation associated with it. These cover such things as the span capabilities, connection locations, stiffener locations etc. It’s all codified and requires no manual input and can link to our ERP system.

Furthermore, I firmly believe that the final finish should be applied on-site. This deserves an article in its own right, but in summary, it allows you to disguise the fact that the building is modular (let’s be honest), it saves space and gets the module out of the factory quicker and it allows for a degree of refinement of the aesthetic not possible in the factory. It also allows larger modules to be transported and reduces pressure on potentially performance-damaging efforts to make the external wall slender. You also don’t have to retain the envelope installers on your payroll.

Lewisham Exchange
Incredibly intricate detailing, patterns and textures can be achieved using an effective ‘hybrid’ method combining the best of offsite technology and onsite installation by skilled operatives. Lewisham Exchange, London.

Aces in their places

Finally, I think many companies would benefit from working in partnership with specialists in two key areas – the load bearing frame, and the building envelope. In the case of the load bearing frame, if you buy an off-the-shelf framing line, in ten years that’s what you’ll still have. If you partner with a company that does this as a core-business, you guarantee to be at the forefront of product and process technology forever. For building envelopes, the case is even more convincing. External walls are extremely complex and subject now to more regulatory requirements than ever, possibly including 15-year statutory defect period. Cladding systems fail much more than people think, and they’re very expensive to rectify. Designing a ventilated system without cold bridges that doesn’t result in long term moisture problems is not straightforward. Materials and finishes are changing all the time. Economies of scale mean that envelope specialists can offer you state-of-the-art solutions at reasonable costs. The envelope is what everybody sees when the job is finished and it defines the quality perception of the project. It’s therefore worth working with the best people and the best systems.

Author: Dr Jonathan Evans, CEO Ash & Lacy