The arguments in favour of moving towards Modern Methods of Construction (MMC) to alleviate acute industry challenges such as stagnating productivity, the housing shortage and mounting waste materials are, by now, quite familiar. One approach to achieving MMC is by prefabricating building components offsite in a factory, resulting in greater speed, higher labour and materials efficiency, economies of scale and tighter quality control (https://bit.ly/3NRwokg).

Those arguments have been made many times by many voices and seem to be having an effect: the offsite construction market is predicted to have a compound annual growth rate of 8% between 2022 and 2027, beating the current UK construction output annual growth rate of 3.9% by more than double.

Offsite manufactured components are not only increasing in quantity but also in their level of sophistication, to add even more value in the factory and save even greater resources on building sites. With that in mind, we can ask some more specific questions about the nature of that enhanced prefabricated future and how to get there. For example – what role can automated coating processes for mass timber play in accelerating progress to this future?

First, it is worth reiterating why wood – especially mass timber systems such as cross-laminated timber (CLT) – is the future of prefabricated construction, offering a number of practical benefits as outlined in Arup’s 2019 Rethinking Timber Buildings study, over traditional materials such as steel and concrete.

Mass timber is lighter, which makes it easier and faster to work with and requires a small, easy to manage installation workforce. This translates to speed of construction, which can have a phenomenal impact in both reducing project costs and accelerating time to sale or revenue generation for the project.

Working with mass timber also creates three-dimensional well-being benefits by creating a dust-free site, safer for the skilled carpenter erectors; requiring fewer HGV deliveries, making it quieter and less disruptive for those living and working nearby; and lowering the stress levels of people in CLT buildings (https://bit. ly/3bUCVxo), creating a sense of calm for occupants.

Of course, the greatest benefit of working with timber shouldn’t be forgotten: the environmental benefit of using a sustainably sourced product that removes and stores carbon from the atmosphere rather than emitting it.

Given mass timber’s advantages, what can we be doing to improve performance even further and to accelerate uptake? At this stage we must begin to look at the finer details.

That’s why, in February 2022, Stora Enso announced a €9m investment in an automated CLT coating line at the Ybbs sawmill in Austria, allowing approximately 500,000m2 of CLT walls and floors to be coated offsite per year (https://bit. ly/3yZUyVP). This offers further benefits:

Speed: In colder and wetter climates, the weather can cause unpredicted delays. With pre-coated components, delays could be avoided. Knowing that the CLT structure is protected also reduces the time spent in quality inspections before it is closed off with internal and external finishes.

Quality and consistency: An automated factory line is unbeatable for quality assurance and consistency of results. With pre-coated components, contractors can be sure of consistent high quality when the product arrives on site. Furthermore, the components are fully protected from day zero, and are not at risk of exposure to the elements during transportation, handling and storage on site.

Visual appeal: In many projects CLT is left exposed internally to create a natural aesthetic. In the coating line Stora Enso can apply finishes ensuring a visually consistent internal finish.

If we are to grow the international mass timber market to create healthier buildings which are built faster, we must zoom into the technological details that will underpin the success of the sector. Automated coating is one such technological advancement that can deliver significant impact on projects.