Future architecture: Lifted off: mini prefabricated house for the city roof

Living space and building ground are becoming scarcer in large cities. Architects and urban planners are already working on the urban living concepts of the future. Such as the "Cabin Spacey". These lightweight prefabricated houses in XS format are placed on the roofs of existing buildings. "Das Haus" spoke to architect Simon Becker, one of the two founders, about the architectural boom.

We know from metropolises such as New York or Hong Kong: If there is a shortage of floor space, you have to build upwards. But with existing building stock, it is often complicated or simply impossible. Nevertheless, the trend to use house roofs is prevailing in large cities, for example for urban gardening projects.

A completely new approach: The two architects Simon Becker and Andreas Rauch are working flat out on the "Cabin Spacey" project, which could create 50, 000 new apartments in Berlin alone - on roofs in the city center. With their 25 square meters, these small space-like cabins should cover all living needs. In spring Becker and Rauch plan to set up the mobile mini-house on a Berlin roof for the first time.

The house: How did you come up with the idea of ​​packing small cabins on apartment roofs?

Simon Becker: We want to help make cities more liveable and enable a generation of urban living space with the highest quality of life. At some point we asked ourselves the question: 'Why has nobody built roofs yet?' As architects, we naturally also have the artistic ambition to attract attention.

The house: How can you imagine your cabin?

Becker: Inside there is a supply module in which all important areas such as the bathroom, kitchenette and bed are housed in one block. The outer shell is building block two, which can theoretically be made in different sizes.

The house: how exactly does the supply module look like?

Becker: Via a gallery above the bathroom, the residents get into a comfortable double bed. If you don't want to sleep on the loft bed, open the reveal in the gable window. In this way, even four people could sleep in the house. The kitchen line runs backwards from the bathroom side wall. Behind it there are chairs and a table - both can disappear on request.

The house: And how does the house on the roof get warm?

Becker: We have provided solar panels on the roof and an electric underfloor heating.

The house: Your cabin is made of wood. That's why you're talking about sustainability: what exactly do you mean by that?

Becker: We rely on wood as a high-tech building material and want to build ecologically, dynamically and flexibly. In the cities, building contractors are still pulling houses up too quickly and far too cheaply because of the housing shortage. We want to oppose this trend with a cabin that is a real shelter for our health - for example with regard to the particulate matter pollution in the centers.

Simon Becker is one of the two founders of "Cabin Spacey" -

Photo: Cabin Spacey

The house: Why wood as a building material? Doesn't that regulate yourself too much as an entrepreneur?

Becker: Wood is a light and highly efficient building material and therefore perfect. Concrete and stone are theoretically possible, but are usually too heavy for city roofs. And with other lightweight designs, you can quickly move towards hazardous waste, so they are out of the question for us.

The house: Is the "Cabin Spacey" only intended for roofs or possibly as an allotment house

Becker: We can also imagine the mini-house on the lake, on the mountain or in a vacant lot. Ultimately, however, we want to use niches - roofs are our greatest resource.

The house: can several cabins on one roof?

Becker: Sure, owners often think about adding one floor to their house. This often fails because of the statics. This is exactly where we come in because the Cabin Spacey is lightweight compared to a real extension.

The house: What does the ideal resident of your cabin look like?

Becker: A young urban couple, both work and use the offers of the big city. In short: young urban professionals.

The house: Would families also be conceivable as residents?

Becker: You could possibly place two or three cabins on a roof and connect them together. Then that would also be a suitable family home.

The house: Where can interested parties turn - how quickly can they get their Cabin Spacey?

Becker: If an interested party comes in, we get started - the production, which is currently still running on demand, takes about six to eight weeks. That means we don't have the houses on the shelves. Often, however, the plot is the problem. In the future we will offer interested parties the entire package of house and building site, i.e. the suitable roof.

Small, smart, practical - and all made of wood so that the residents feel comfortable

Photo: Cabin Spacey

The house: Is it a prototype or can other variants be selected?

Becker: We have developed a standardized product, theoretically two to three levels are conceivable. We distance ourselves from individual solutions, however, because this creates high additional costs. Instead, we focus on the smallest possible unit in order to be able to occupy as many niches as possible.

The house: How much does the Cabin Spacey cost?

Becker: The prototype costs 100, 000 euros, and we sell 50, 000 to 100, 000 euros depending on the quality of the execution.

The house: What options do I have as a building owner?

Becker: Wall structures made of solid wood, for example, are expensive;

The house: the cabin is still not cheap, is it?

Becker: It is important to us to deliver good quality at the best possible price. We definitely don't want to be a low-cost provider.

One surface, two floor plans: one shows the ground floor with a bathroom, the other the sleeping area on the bathroom cabin. Please click on the image to enlarge it!

Photo: Cabin Spacey

The house: How do you differentiate yourself from the competition - for example the Tiny House University, a community of people interested in architecture and design who has created a rolling mini-house for the city center

Becker: We are a member of the Tiny House University ourselves and consider our colleagues as cooperation partners. Our USP is a combination of roof area and tiny house, whereby tiny means cute. We tend to coined the term minimal house in combination with ecology. And thus prove a relatively fresh topic. There are hardly any products like ours for cities.

The house: What are the structural requirements so that the Cabin Spacey can land on a house roof?

Becker: Our professionals have to check this in individual cases. The biggest hurdle is the stairway to the roof - the residents must be able to reach their house.

The house: Do you also offer solutions so that you can even get up on the roof?

Becker: First of all, we want to concentrate on roofs that already have an exit. There is plenty of that in Berlin. But in general, of course, we want to offer solutions, otherwise the hurdles for the builders are too high.

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The house: Is it so easy to build a roof?

Becker: The building regulations are not entirely without. On the one hand, the density of the buildings plays a role, but also fire protection, insulation and fall protection. You also have to protect the roof from damage, so prepare the roof accordingly for the cabin. Our technology layer - as we called it - has to clarify access, flooring, static removal, technical connections and fall protection.

The house: How is the cabin up there at an airy height? With the crane? Or do individual parts arrive?

Becker: Both are generally conceivable. However, our prototype is actually manufactured in the factory, transported on a low loader and then placed on the roof by crane. Depending on the size of the street and budget, this can be two small cranes or one large mobile crane. But that is also more expensive.

The house: When do you build your first house?

Becker: It will be ready in spring. We are currently working with a Berlin housing association to clarify the exact location and are in talks with the city planning office and building authorities.

The house: will you try out the Cabin Spacey yourself?

Becker: Of course! I live in Friedrichshain in a new apartment on the 7th floor just below the roofs of Berlin. So I really want to go to the roof and try it out there. We also want to further optimize our product.

50, 000 roofs in Berlin alone could be equipped with the "Cabin Spacey"

Photo: Cabin Spacey