Interview

The first printed home has a bath by Bette

Beckum in Münsterland is now home to Germany's first single-family house built using the 3D concrete printing process. The visionary project features a Bette bath and two Bette shower trays. Architect Alexander Hoffmann and plumber Tobias Leifhelm tell how 3D technology is also changing the planning and construction process in the bathroom.

Alexander Hoffmann from the architectural firm Mense - Korte
Tobias Leifhelm from the installation company Leifhelm & Pelkmann

Mr Hoffmann, Mr Leifhelm, now that you have realised Germany's first printed residential building: Is 3D printing the construction method of the future?

Alexander Hoffmann: 3D printing will certainly help shape the future, because we can use it to solve problems that the construction industry is facing: The industry is no longer finding young talent. 3D printing opens up new perspectives: The bricklayer 2.0 no longer stands on the construction site with a trowel, but with a laptop. That is of course incredibly exciting - especially for the younger generations.
 
Tobias Leifhelm: We need skilled people in the trades. We have to try to change the job description in people's minds. A 3D printing project like this shows: Hey, there's also something innovative, fast and forward-looking.

How does 3D printing work exactly? How does the house come out of the printer?

Alexander Hoffmann: It's not witchcraft. It's best to imagine a printer like the ones you use at home, only with x, y and z axes. In Beckum it was exciting for us to see what it's like to print outside in the fresh air when the sun is shining, the wind is blowing or it's raining. Before we had only printed in a hall. That's why we first built a tent around the printer. In the future, I'll just put the printer on the building site and then create my floor plan layer by layer.

How big is a printer like this?

Alexander Hoffmann: In Beckum we had a printable span of 12 and a half metres, a height of 15 metres and a length of 7 and a half metres.  and a half metres, 15 metres high and 7 and a half metres long. 

And the printer nozzle then sprays the concrete like a cream sprayer.

Alexander Hoffmann: Exactly. It works like decorating a cream cake. The special concrete-cement mixture comes out of the nozzle layer by layer.

And how long does it take to print a whole house?

Alexander Hoffmann: We needed a total of 100 printing hours. Sometimes we printed ten centimetres a day and then had to check again whether everything was working properly. In the future, the printer will be in operation 24/7, then we can print a complete floor in 3 to 4 days. 

In comparison: how long would it take to build a house using conventional construction methods?

Alexander Hoffmann: The special feature of this house is that it has rounded corners everywhere. rounded corners everywhere. Such features are very demanding to implement in conventional construction and cost a lot of time. With 3D printing, we save about 50 per cent of the time. 

What are other advantages?

Alexander Hoffmann: The design freedom for the architect and the client is great, of course. Then there are the short construction times. The material savings. I need less manpower on the construction site, two to three people are enough. And the fact that we can implement the ancillary trades at an early stage and thus achieve a high planning quality. We can also reduce a lot of waste.
 
Tobias Leifhelm: It's really great that you can be so creative. That we can find individual solutions that are also economically justifiable.

How does the construction process change in the bathroom?

Tobias Leifhelm: The bathroom is a very demanding space. Many trades are involved there. If everyone is on board from the beginning, you also achieve good results. That's exactly what the 3D printing process requires, i.e. that you coordinate all technical and design-related issues with everyone involved at an early stage so that everything fits and works in the end. The result is then also much better. 

Why did you choose Bette?

Tobias Leifhelm: Bette is simply very convincing in terms of the quality of its products, is creative, flexible and reliable, simply a dynamic family business. From the support, the communication, the technical support - everything is just right. They came to the project and explained again how the mounting frame is set and how the sealing works. The big challenge was that the curvature of the wall had to fit the bath. The frame to hold the bath was also printed and the bath was put in there. And we were all really relieved when it all actually fitted. Because neither the bathtub nor the house could have been changed afterwards. With Bette, you could tell that they put their heart and soul into it right from the start. You need that kind of support, otherwise you can't realise such an ambitious project.
 
Alexander Hoffmann: With a project like this, it is extremely important to have motivated people involved. We are doing research and innovation here, you have to get everyone around the table and think about how to solve a problem. I sweated blood and water over the bath. We had previously received a 3D file from Bette with the exact curvature of the bath, and we fed this data into our planning tool. But the fact that the bathtub really did fit perfectly in the end was of course simply super.

What did you learn from this project?

Alexander Hoffmann: The high degree of digitalisation guarantees a final, well thought-out building. That's just great.
 
Tobias Leifhelm: That such buildings are a lot of fun to implement, as long as you have the right team.

When will you build the next 3D house?

Alexander Hoffmann: We have many things in the pipeline. We are currently printing Tiny Houses in southern Germany.
 
Tobias Leifhelm: We have a great desire for further projects and are excited about everything that is still to come.