The new homes come off the assembly line

In the factory of construction company Plegt-Vos, two employees have just cleaned a robot. The rock song blares through the factory hall ready to go from Republica on the construction radio, occasionally drowned out by the hammering of the carpenters and the hum of the machines. The robot spans a treadmill like a metal bridge, and a complete facade of a house fits underneath. In the last step of the production process, the robot arm presses brick slips into an adhesive layer on the wooden facade part. The thin sand slabs have the colour, relief and dimensions of a brick. The industrial glue resembles grout, from a distance the wall looks like masonry brick.

Manager Gerard Peelen holds up a brick slip with a grin. “Actually, this is mainly optical, because in the Netherlands we are used to houses being made of brick. The facades we make here insulate – even without the strips – just as well as brick.”

The ‘brick strip robot’ next to Peelen is the end station of the production line in Langeveen in Overijssel. At the front, wooden beams enter, which are screwed to a facade in eleven hours, insulated and provided with glue and stone strips. Behind the factory, rows of finished facades are waiting for transport to construction sites in Amsterdam, Zwijndrecht and Odijk. There they will soon be hung against concrete hulls, like a large construction kit that already contains the doors, frames and windows. Twelve facades roll off the production line every day.

The last robot places up to 12,000 bricks per day. Peelen: “If you use traditional bricklaying at that rate, you need twelve bricklayers. No bricklayer came to see this facade.”

There he immediately touches on the biggest problem that the construction industry is currently facing. While the demand for new homes has not been this great in years, there is a huge shortage of skilled workers. And then the EIB, the economic institute for the construction industry, estimates that another 25,000 construction workers will be needed by 2030 if the cabinet wants to realize the intended 100,000 homes per year.

Due to this lack of personnel, major Dutch house builders invest in factories to make walls and facades. For example, construction group BAM announced in November that it would open a housing factory in Oudkarspel in 2023, where work will mainly be done with wood. VolkerWessels has been working with prefab parts from the factory for several years now. The biggest advantage: more can be built with fewer people.

Faster and more modern

For Plegt-Vos (507 employees, 2021 turnover: 275 million euros), the decision was made to give priority to industrial construction at the beginning of 2020. The production line in Langeveen was still under development when the corona crisis broke out. Even before the first facade was completed, the management was already making plans for a much larger housing factory in Almelo. Over the next five years, a factory complex will be built on ten hectares there, where 7,500 to 10,000 homes will eventually roll off the production line with the help of robots.

The first of five halls is now ready and will be filled with machines this week. Innovation manager Berri de Jonge looks at the production floor, which is still empty. “Slightly more than the surface of a football field,” he estimates. De Jonge supervises the construction of the production line in Almelo. It will be comparable to the one in Langeveen – only much faster and more modern. The robots in Almelo produce at least ten times faster. “We can make facades for four thousand homes in this hall at full power every year.”

Of the 1,250 homes that Plegt-Vos built last year, about half come partly from the factory in Langeveen. If it’s up to director Theo Opdam, that share will go up quickly. “In five years that should be 90 percent of our housing construction. Moreover, we now also work with concrete hulls. When ‘Almelo’ is fully operational, we also want to make those hulls based on wood. Then the houses come out of the factory as a whole.”

Less CO₂-emissions

The housing factory solves more than a personnel problem. Construction companies are also still struggling with high CO₂emissions. Because industrial construction production takes place indoors, this saves a lot of construction waste emissions of CO₂, especially when wooden frames replace heavily polluting concrete. Opdam: “We had the performance of our factory in Langeveen calculated by TNO, which resulted in an emission saving of 35 percent. That will increase to about 80 percent if the factories are running optimally and we start making the hulls from wood.”

Professor of architectural engineering Thijs Asselbergs, affiliated with TU Delft, also points out the price advantage of industrial construction. “You can build more with less manpower. That cuts costs, and that is the holy grail for everyone in politics and construction.”

At the same time, Asselbergs makes reservations about industrial construction. “You are strongly tied to the machines in the factory. A traditional construction worker with his tools can get everything very precisely to size. That is often more difficult in a factory.”

Berri de Jong recognizes that objection. Standard apartment facades can be made with great speed, but it is not possible to work with round shapes, for example. “If it has to be built on very small plots or with certain difficult corners, it becomes too specific and the advantages of industrial building disappear.”

The limitations of machines turn the relationship between builder and architect upside down. Now it is usually the case that the architect makes a design, which then realizes the construction. De Jong: “In industrial construction it is the other way around, where architects have to make a design that is tailored to the capabilities of our machines.”

Boring uniformity

Professor Asselbergs, who is originally an architect, voices another criticism of prefab construction: the risk of uniformity. “You don’t just build blocks of houses, you also create a neighbourhood. During the reconstruction we saw how that could go wrong.” It is important that you bring together different styles, different types of living. “That determines the environment, the appearance and the living pleasure of a neighbourhood.”

Plegt-Vos director Opdam vigorously combats the fear of boring uniformity. “The robot can be set differently per facade type. We can build an enormous number of types and types of houses. We are learning more and more and getting better. The possibilities will only increase in the coming years.”

Yet Asselbergs remains critical. “Preventing uniformity requires more than just using a certain nice stone. To make a neighborhood a pleasant living environment, you need an enormous amount of ‘design power’. Architects and designers play an important role in this. Construction companies must continue to involve the designer, the architect and the ultimate occupant in design and construction.”

Because the machines in the factory make a lot of traditional work superfluous, there also seems to be less room for the craftsman. Does the bricklayer disappear because of the house factory? According to Opdam, things will not go that smoothly. “As long as there are still stone houses and monuments to be rebuilt and renovated, professionals will continue to be needed. I’m convinced of that.”