Modular houses: building according to the Lego principle

Creating more affordable living space quickly: serial modular construction could help here. But it is not a panacea – the problem of the lack of space remains.

The modules come from the factory. They are ready-made rooms with sockets, tiles and bathtubs that only have to be plugged into one another on the construction site like Lego blocks. kwb, Kommunale Wohnungsbau GmbH Rheingau-Taunus, has already built a total of 91 residential units in this way, the first in 2019 in Idstein, Hesse.

Four months to move in

Managing Director Ditmar Joest was particularly impressed by the fast construction time. The building in Idstein was built by kwb in the middle of an existing residential complex. Less construction noise, less dirt – this is also much more pleasant for the people who live right next to the construction site. “There was no negative response from the residents at all, they found it rather exciting how quickly living space can be created,” says Joest.

The first apartment building in Idstein was built within eight weeks and was ready for occupancy after four months. With conventional construction, this would have taken 12 to 14 months. Housing industry associations therefore see serial modular construction as an opportunity to create living space faster and more efficiently. And the new federal government also wants to promote the issue in order to achieve its goal of 400,000 new apartments per year.

Axelexpanding, board member at the VdW Südwest association, welcomes this. For him, the advantages of modular construction clearly outweigh the disadvantages. If you build with ready-made building blocks from the factory, you can calculate costs better. And it takes less time to plan. “Housing companies can basically choose houses from the catalogue,” says Thousand Pounds.

So far no cost savings

However, modular apartment buildings are still a niche. Their market share in Germany is negligible – according to VdW Südwest it is just four percent. Why is that? “I think it has to do with the fact that when you hear the word module in Germany, you quickly think of prefabricated buildings – and they don’t have a good image,” saysexpanding pound. Wrongly so, because modular houses in Germany have to meet the same quality criteria as conventional buildings. When the building is standing, you can’t tell the difference visually either.

So far, however, it has not been possible to save money and thus rent out apartments more cheaply with prefabricated apartment buildings from the factory. The demand from the few providers is still too low for that. This could only change when many modules are mass-produced. And there are also problems that the entire industry is struggling with – for example, a lack of building land and lengthy approval procedures from the authorities.

Long lead times of construction projects

For Ralph Henger, real estate economist at the German Economic Institute in Cologne, the lack of building land is the crucial bottleneck. They are scarce, especially in large cities, where the demand for living space is particularly high. For Henger, the announcement by Federal Building Minister Klara Geywitz from the SPD that she would push ahead with modular housing construction in order to speed up construction distracts from the central problem and should therefore not be hung up too high.​

Kwb managing director Joest would like to build more, faster and cheaper. But he also lacks the imagination as to how to do this given the existing requirements. It is not unusual for a construction project to have a lead time of ten years. “I’ve also never seen a building authority say: We’ll do without this or that so that it goes even faster.”

From Joest’s point of view, modular construction is not a panacea because it does not work for every project. But precisely where space is tight and areas are being densified, building according to the modular principle is the solution for him – if only to reduce the annoyance for the surrounding residents.