Description

Situated on a busy road on the edge of Heilbronn, the new building has been inserted into a disparate neighbourhood in which car dealers and petrol stations stand alongside dilapidated residential buildings. The project aims to maximise the use of the restricted site by significantly reducing the amount of square metres per person without overly limiting the residential qualities.

Joos Keller Architekten have responded with a timber micro-apartment module that has been meticulously designed down to the last square centimetre. Through the intelligent organisation of surfaces and high-quality materials, the micro-apartments offer a high quality of living despite their small size. Some two dozen of these boxes have been stacked to form a residential complex that is designed for short stay occupation, e.g. as a boarding house, but can also be used as student apartments over a longer period of time. In Heilbronn, the apartments are primarily intended for students during work placement or as accommodation for company staff who stay in the city during the week. The concept is transferrable to other user groups and locations.

The L-shaped plan of the building is a product of building regulations that restricted building over the area that is now the forecourt. The complex has 23 residential units spread over three floors, 20 of which are single modules with a floor area of 17.5 m², and 3 of which are double modules with a floor area of 35 m². The gallery walkways in front of the building serve as a buffer zone to the street and to shade the interiors, and can also be used as a communal space, especially in summer as it faces south-west. The timber modular construction is both space efficient and ecological, and the high degree of prefabrication reduced construction time while also making it possible to develop special solutions to make optimal use of the floor plan. A side-effect of the exposed structural timber in the interior is that it is both aesthetically pleasant and good for the room climate. The wood is complemented by robust surface materials such as laminate, linoleum flooring and stainless steel.

An energy concept was developed for the entire complex that aims to maximise the use of renewable energy to keep running costs down. Photovoltaic panels generate electricity, which is stored in a house battery for the residents’ use. The electricity is also used to heat water. All the apartments have underfloor heating and local controlled ventilation with heat recovery. This concept, coupled with the advantageous physical properties of the timber construction, means that the building easily fulfils KFW-55 standard.

The interior of each apartment is divided into living and sleeping areas by a fitted insertion that divides the space. The bathroom can be partitioned off with a sliding door but also receives daylight and is equipped to a high standard. The windows are installed flush with the facade, making the rooms appear larger and creating seating and storage areas along the entire window side. Ample storage space is provided and underfloor heating distributors and WLAN routers, for example, are located in the bench in the living room.

Originally published in Bauwelt 21.2018, pp. 30-33, abridged and edited for Building Types online, translated by Julian Reisenberger

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