Site Lines: The Future is modular – Legal & General’s CLT Factory

In the wake of the damning Farmer Report on the construction sector’s ineffiencies, architect Rory Bergin reports from a recent visit to Legal & General’s CLT factory which points to a truly modern CLT alternative future.

I have seen the future and I expect it to work really well. We have heard this, or its like many time in the past. The recent history of housing manufacturing in the UK is littered with names that started up factories to manufacture housing, promised great things, failed to deliver and duly died. Not only was this sad for the businesses concerned, but it did quite a bit of damage to those in the industry who favour industrialisation, as these businesses failed usually in the middle of projects, leaving clients high and dry, or failed after buildings had been built, leaving their clients in a difficult situation regarding insurances and maintenance.

So when a new manufacturer hits the headlines with tales of a new factory, promising to deliver a sizeable chunk of the new housing market, my first reaction is one of scepticism. I want to hear about their accreditations, their processes and most importantly their funding. The one thing that has led to most of the failures in housing manufacturing businesses has been a lack of funding to keep them running in lean times and to enable them to survive the cyclical nature of the housing industry.

Legal and General, however, is a different kettle of fish. Every question put to them elicits a surprising response, different from every other manufacturer I have spoken to.

Why are you setting up the factory?
We want to invest pension money into a stable market.

How big is the factory?
The biggest in the UK.

How well-funded are you?
L&G’s reserves are substantial.

Can we take photos?

Why? Most factories are secretive about their technology, why aren’t you?
If anyone has £50m to spare they are welcome to follow our lead.

Why CLT?
It comes in large, stable panels, we can dispense with joints in the construction and all the problems they bring.

Where will you get all that CLT?
We are buying it in for the moment, but we are also building a new manufacturing facility to make it on site.”

And so on.

This is not a factory based on some bright technical ideas, although they have plenty of those too, but instead it is based on a pragmatic need to provide income for a pension fund over the long term. This long term need inevitably produces the question, how can they build quickly so that they can get a return as soon as possible, and build well so that the return is guaranteed for a minimum of 30 years, and potentially much longer. The answer is to build the homes in a factory to guarantee quality and speed, and make them from CLT to guarantee their long life. A CLT panel is one of the stiffest, most stable materials available, has no joints if you use one that is big enough, and shouldn’t move in 30 years.

This answer will surprise a housebuilder who is able to build homes very cheaply by putting pressure on the supply chain and building similar types everywhere, but who has no interest in the long-term life of the building. The difference in business model brings about a very different product.

L&G are unlikely to compete directly with the housebuilders, and expect that local authorities and housing associations will be their natural clients, as well as building their own developments.

When it comes to the technology itself, the superlatives come thick and fast. If you like big machines, you are immediately in heaven in the L&G factory. The largest CNC machines available, the largest panels of CLT that are being manufactured, a purpose-built machine to move modules around the factory floor, and so on. It is a very large set of boys toys. When the factory is in production, it will also manufacture CLT panels, something that is not currently available in the UK. The first production runs will use imported panels until the CLT manufacturing plant is functioning. One of the many benefits of this is the lower cost, but it also means that the factory will produce almost no waste, as any offcuts from the production process go back into the CLT manufacturing to be turned into new panels, or burned in the biomass plant to heat the factory. When you compare this to the 20-30 per cent of waste on the average construction site its not hard to see the benefits of factory processes, not just in monetary terms, but in planetary terms.

The CLT will be turned into large room sized modules, fully fitted out internally, and delivered to site on trucks. The point of this is to de-risk the process and take site trades out of the equation. The CLT panels will be routed out to provide space for wiring and then finished with a cement-bonded particle board to give a flat finish for paint. The particle boards are supplied as room sized elements to remove the need to joint and skim them. There goes the plasterers job! Doors and surrounds are made by machines and assembled in the factory, there goes the chippies job, and the bathrooms are clad in stone sheets, so no tilers required.

The attitude of the team is iconoclastic and disruptive, aiming to re-engineer the process of housing delivery, and with L&G behind them it, it is much more likely that they will succeed than not.

For architects, this offers an opportunity to design new, highly sustainable housing, built to superlative quality to exacting dimensional standards.The factory will produce whatever is required, as the machines don’t care if they do a job once or a thousand times, it makes no difference to them. There will be some restrictions on what can be designed, as there are limits to the size of a module imposed by transport regulations. Internal detailing will be set by the factory more than by the architect, so there will be fewer opportunities for specification of interiors than traditional construction offers, but the facades will still largely be constructed on site to allow for local flexibility.

The benefits that come with this type of industrialisation will make any design restriction worth it. I expect sites to finish a year quicker than those built using traditional construction, with far fewer defects, less transport miles, less waste, and with a renewable material. As this develops in scale, perhaps it  is time to open the issue of embodied energy in Part L to account for the superior contribution to climate change mitigation that this form of construction offers.

In short, this is a game changer. It heralds the arrival of large-scale factory production into a sector that has needed this for a couple of decades. It ticks all the boxes of Mark Farmer’s report into the failure of the housing industry to modernise. It is a breath of fresh air and I wish them every success.

Rory Bergin is partner, Sustainable Futures, at HTA Design. L&G Homes will be hosting a seminar on Cross-Laminated Timber Modular Housing as part of the Materials 2017 conference programme.