Darmstadt Technical University's project, Cubity, is student accommodation with a difference. It only costs €250 a month to rent and produces more energy than it uses, making it very eco-friendly.
But this saving comes with one significant downside: the rooms are only 7.2 square metres in size, almost two square metres smaller than the legal minimum for a child's bedroom in Germany.
Built in Frankfurt's Niederrad district in the south-west, the Cubity building is a 16m-by-16m cube with an outer wall of glass, inside of which are individual cubes for each of the 12 inhabitants. Each personal cube is 7.2 square metres and has a bed, a desk and an ensuite bathroom.
In the cramped rooms, everything possible is done to save space. Drawers and wardrobes are hidden in the beds and the desk slides back into the wall.
The university is trying to prove with this project, which is sponsored by prefab house company Holding AG, that one can build homes in a space saving and innovative way.
The bedroom cubes are stacked to create two storeys and are grouped around a communal eating area called the "Marketplace". There is also a roomy kitchen and another communal area for reading and watching TV.
Living and sleeping in the cube, however, takes some getting used to, “in seven square metres you quickly reach your limits” law student Kai Julian Kemmler explains.
Inside Cubity. Photo: DPA
One of the main appeals of the project is that the building is the first student home worldwide to conform to the "plus-energy standard".
This means that the building produces more energy than it consumes, feeding energy back into the national grid. Cubity does this with photovoltaic panels on the roof which produce electricity for the whole house.
Architecture students from the university designed the house and were rather inventive with its systems. The house is heated and cooled using pipes which go through the floor and ceiling. Depending on the time of year, either hot or cold water is pumped through the pipes to either heat or cool down the building.
The innovative new systems don't always work as they are supposed to, however, as the cubes get very hot in summer and the cooling system can take some time to get going. Elisa Stamm, who supervises the project's scientific side for the university, admits the flaws but says "it can't be perfect from the beginning".
As in every student house, some housemates are cleaner than others, which can cause arguments. Additionally, the cubes aren't very sound-proof, so the inhabitants introduced a rule against cooking or putting the washing machine on after 11 pm.
Another issue that has arisen since the project's beginning is that none of the initial inhabitants could choose who they were living with as student services offered places on a first-come-first-served basis. But in the future, housemates will be able to interview and choose their own applicants.
Despite the project's flaws, none of the original housemates have thus far chosen to leave, even Kemmler, who criticises Cubity, has no intention of leaving as the "€250 rents are unbeatable".
What's more, finding student housing can be a long process - last year, when Kemmler was looking for a "normal" home in Frankfurt with student services, he was 800th in line.