Robots, laser projection, 3D printers and inspiration from the automotive sector may not typically be things you associate with UK off-site timber frame home production.
But those are some of the developments implemented by one forward-thinking UK timber systems producer as it seeks to supply the low-carbon homes required for a construction sector short on traditional building skills.
Donaldson Timber Systems (DTS), part of the long-established family-owned timber products company The Donaldson Group (DG), has set down an industry marker with a recent £10m investment at its timber homes factory at Witney, Oxfordshire.
Some of the pieces of new technology were created specifically for DTS and have never been used before in the industry.
For DG, the venture into timber frame systems is a recent one, having acquired Stewart Milne Timber Systems (SMTS) in 2021, then comprising three factories in Witney, Aberdeen and Falkirk.
When TTJ caught up with DTS managing director Rod Allan and manufacturing director Frank O’Reilly following the £10m factory investment, it was an opportunity to explore in more detail how the company is seeking to position itself in the off-site low carbon homes market.
FULL TIMBER CONSTRUCTION SOLUTIONS
Mr Allan explained the reasoning behind DG’s venture into timber frame.
“Timber frame was a natural addition to The Donaldson Group, which is timber through and through,” said Mr Allan. “It’s a bit of vertical integration and it fits nicely with the Donaldson roof truss business.
“With the Group being based in Scotland, we have a good view of the marketplace as timber building in Scotland is more than 95% of new houses. We see the low-carbon and environmental credentials of timber frame and the opportunities in England.”
When DG added timber frame it meant there were three parts to the Group’s Off-Site division – Donaldson Timber Engineering (DTE), which manufactures engineered timber floors and roof trusses; Donaldson Door Systems; and the newly-created DTS business.
Essentially, it added wall production to be able to provide full timber construction kits to the building industry.
Mr Allan estimated timber frame’s market share of the English new homes market to be around 15-16% but it is set to break 20% as the market picks back up.
“Some of the big builders have seen what the future looks like and have invested in their own timber frame businesses, such as Barratt, Miller and Avant, through acquisition,” he added.
“I’ve no doubt the rest of the market will move in that direction as well.”
When JDG acquired SMTS it inherited two large timber frame hub factories in Witney and Aberdeen. A third, small site at Falkirk was closed in February in response to current reduced housebuilding demand.
The investment in Witney was to industrialise the Sigma II closed panel product, which is fully insulated and with pre-fitted windows, as well as to produce fully finished floor cassettes including glued chipboard floors.
“This was to enable housebuilders to get “wind and watertight” within a day.
“Up until this investment, we could, with three shift working, maybe make 600 Sigma II units a year,” added Mr Allan.
“This investment will see the capacity to produce somewhere between 3,000-5,000 units, depending on how big the houses are.”
Mr O’Reilly explained that when SMTS opened the Witney factory in the early 2000s, it was one of the most automated timber frame factories in Europe.
“It had been an ambitious and brave thing for Stewart Milne to do at that time,” he said. “He took what he had learned in Scotland and knew that the English market was a growing market.
“The equipment is still very functional, but the market has changed a little bit and there is definitely a push to more of a closed panel product.”
RISE OF THE ROBOTS
DTS partnered with Sweden-based timber frame technology specialist Randek on the project, developing new techniques and innovations in the process.
One of the new features in the factory is three robot production cells with eight Kuka robots in total.
“Why did we choose robotics?” said Mr Allan.
“We know the market will change. Previously, the machinery here was designed as very bespoke, aimed at doing specific things, but the beauty of robots is they are very easy to reprogramme and repurpose.”
For instance, robots can be fitted with a variety of tools – from nailing guns, to routing heads and also suction cups for lifting.
“It helps us to be future-proofed. We’re trying to give ourselves as much flexibility as to what comes in the future.
“The automotive world is miles away from the timber frame world but there are things you can learn.
“It seems like a leap of faith, but the automotive world has been doing this for the last 40 years. There is no-one else doing what we’re doing with robotics in timber frame.”
With one eye on the future, DTS has designed in some blank workstations in factory areas for future potential add-on operations.
Mr O’Reilly toured a number of factories across Europe and the US in preparation for the investment.
“There was nothing that we had seen that ticked all the boxes, so we worked with Randek to adjust our equipment to suit our needs.
“I would say our production line is now world class, there is nothing like it, either across the US or in Europe.”
Technology relationships were also maintained with machining specialists Hundegger and Weinig, while extraction equipment supplier Indusvent added a system to the production line to efficiently extract the sawdust.
Considering the new production line is 130m long, the extraction installation required ingenuity by Indusvent, who worked with Randek on outlet sizes and booster fans to optimise the system.
Another important supplier is Millennium Control Systems, whose expertise with PLCs assists DTS to extract and understand data on the production line to optimise operations.
A further ambition of the investment was to save production time by moving away from manual measuring teams working with drawings and tape measures to automatic laser projection.
“The mantra of ‘measure twice cut once’ rings in everyone’s ears,” said Mr Allan.
“But every time someone looks at a drawing and picks up measuring tape that is lost production time,” he added.
“As part of this investment, we have invested in laser projection technology, which means you don’t need to get a measuring tape out and you don’t need to look at a drawing.”
Green laser lines are projected onto a work table and staff place timber along the lines.
“This is all in an attempt to de-risk the manufacturing process,” added Mr O’Reilly.
“The equipment will only make lines as according to files transferred to the factory floor. It removes the human factor where someone has misinterpreted a drawing and misread a tape measure.”
This technology is routinely used in roof truss production, though not for timber frame panels.
FULLY FINISHED FLOOR CASSETTES
Another big improvement at Witney was in floor cassette production.
“We produced floor cassettes previously, with an automated production line at Witney. But the product has changed and demand in the market has moved to a fully finished floor cassette, as the lack of site trades have made it more difficult for builders.”
Challenges that needed overcoming to meet BBS and NHBC requirements included the correct detailing of how glue was inserted into the tongue and grooves of the chipboard flooring panels.
An integrated technology solution was developed to lay boards onto the floor framing and for efficient T&G gluing.
This is where DTS’s astute recruitment and inspiration from the automotive industry helped.
When the Honda factory in Swindon closed, several automotive engineers were recruited, bringing fresh ideas and solutions to the Witney timber frame operation.
One of these was the decision to buy a 3D printer to solve the T&G board gluing issue. A twin chamber nozzle was designed and printed to provide an effective solution and ensure NHBC certification for the fully finished floor cassette system, giving customers confidence of optimum performance.
“We have moved advanced timber frame manufacturing away from the image of some guys with a bunch of nails and a hammer,” added Mr Allan.
“Automation, repeatability, technology transfer, production monitoring such as thermal imaging and vibration analysis – this is the direction of travel.”
DTS is also working with timber/board raw material suppliers to supply bespoke sizes to the factory in order to reduce the number of machining and processing activities and reduce forklift movements.
LOOKING FORWARD
Currently, the DTS operation across Witney and Aberdeen now has a capacity of about 9,000 houses per year.
“We have this hub and spoke strategy, which allows us to add capacity very quickly if we need to,” said Mr Allan. “We could easily produce 12,000 without breaking sweat [by increasing shift patterns].”
Mr Allan said DTS will produce about 5,000 houses in 2024, a reduction of 20-25% on normal levels due to the current market situation. And he estimated DTS’ share of the UK timber frame home market to be approximately 14-15%.
“There are two directions of travel in timber frame manufacturing, either volume, volume, volume, or there’s value,” said Mr Allan.
“We’ve covered the best of both worlds in that we’ve added volume but we’re also adding value by industrialising the Sigma II system.”
DTS’ full timber frame panel product range starts with Alpha as a standard open frame system, then Delta, which includes insulation, before the top-of-the-range Sigma II product. The Omega fire-rated variant product utilises Fermacell class zero boards.
Elsewhere, photovoltaic (PV) solar cells have been installed on the factory roof and will produce just under one megawatt of electricity, covering the factory’s own energy needs and an excess of green energy that is exported back into the national grid for other local businesses and homes to use. This significantly reduces the site’s environmental footprint and, combined with new electric vehicle charging points for staff and visitors, supports DTS’ sustainability goals.
“The installation of this new machinery in a working factory is unusual for the industry and the process required a phenomenal amount of logistical planning over a period of a couple of years,” concluded Mr O’Reilly.
“We’re all really proud of the results. We’re creating the capacity and technical capabilities customers require to continue building more advanced and energy-efficient homes and buildings – and future proofing our own business in the process.
“We’re also excited about what this means for our colleagues, as it is revolutionising the operations process. Now a less physically demanding role, we can hire a wider variety of people to work on site, helping to plug the current skills gap in construction. These efficiencies also provide an opportunity to increase production, creating more positions in time, and allowing us to redeploy people to more value-added roles.”
Mr Allan said DTS would continue to look forward and innovate.
“We have created the scope to add more capacity and capabilities to the factory over time without the need for a large-scale overhaul like this one, and we have created a platform for more R&D.
“This is a significant investment but one that will set us and our customers up for continued success in reducing carbon for years to come.”
For DTS’s main technology partner Randek, prefabrication isn’t just about constructing buildings; it’s about co-creating solutions with its customers, refining their processes, and integrating its technology to drive efficiency and automation.
“This synergy not only makes housing more affordable but also paves the way for a sustainable future,” said Ola Lindh, Randek chief executive officer.
