CONSTRUCTION METHOD

The building was designed as a simple timber hybrid structure. The underground car park, half of which is underground, forms a reinforced concrete 'table' on which a four-storey timber structure stands. This consists of soundproofed, stacked room modules made of cross-laminated timber. The stairwells are on the outside, maximising living space and creating a compact and cost-effective design.

Due to the requirements for sustainable construction and high energy quality of the building, as well as the general objective of using as many renewable raw materials as possible, the architects proposed that the building be constructed and finished mainly in wood.

The building was planned as a simple geometry with recurring identical components, consistently superimposed load-bearing structures and shafts. Serial and standardised construction, as well as a high degree of industrial prefabrication in timber construction, ensure economical construction and short construction times. The apartments and communal areas are delivered to the site as prefabricated modules with integrated sanitary facilities, raw installations, windows, doors and finished surfaces. Only the facade elements and prefabricated installations are assembled on site.

ACCESS AND UNDERGROUND PARKING

The property is accessed from the south via Hugo-Hesse-Strasse. Two paths lead from the street to the external staircases. The underground car park is accessed via a gently sloping ramp (6% incline), which provides some of the required parking spaces. In addition to car parking, the underground car park also provides ample space for bicycles.

COMMON AREAS

In addition to the apartments, the ground floor will include communal areas: a lounge with a kitchen and a laundry/drying room with a café. In front of the rooms and next to the staircases, there are terraces as communication zones, facing the existing green space. Inside the building, a small green courtyard is planned as an introverted meeting place and show garden. The communal areas can be opened up through thermally insulated garage doors, creating a large continuous area in the summer.

TREES AND SEALING

The new compact, punctiform structure maximises the preservation of the valuable tree population and minimises surface sealing. In addition to preserving the existing trees, a green roof and intensive courtyard planting will offset the use of space and improve the microclimate. The underground car park, which is only half underground, reduces costly excavation to a minimum.

HEAT AND HOT WATER

An air-to-water heat pump is the preferred energy source. A solar thermal system can also be included in addition to the photovoltaic system. Due to the geographical location of the building, solar energy can also be used in spring and autumn. A combination of photovoltaic and solar thermal energy is also possible through the use of PVT modules.

Heat pump radiators will be used to heat the living areas. A home station will be installed in each unit to provide hot water. This is a special small transfer unit consisting of a heat exchanger for heating domestic hot water. There are several advantages to using such home stations: Firstly, the meters for measuring energy and water consumption are already present in these stations. In addition, the user-specific generation of the required hot water demand per residential unit means that there are no heat and circulation losses in the pipe network, as only one cold water pipe needs to be installed in each unit.

VENTILATION CONCEPT

A flat ventilation system is installed in the apartments. An appropriate amount of outside air is introduced into the rooms through the window rebate ventilators and transported through the roof via the exhaust air element in the bathroom. This provides ventilation according to need and prevents biophysical changes to the building fabric. The energy still present in the exhaust air is recovered in the area of the roof fan and fed back into the energy cycle of the heating system.

As an alternative, controlled ventilation can be decentralised by means of an individual room ventilator with heat recovery integrated in the windows.

SANITATION AND RAINWATER DRAINAGE

Retention areas are provided to retain rainwater in the event of heavy rainfall. For example, the roof areas are designed with extensive green roofs and the courtyard areas with intensive greening. Other retention options include the installation of retention cisterns and rainwater storage systems. Rainwater will also be used as service water for toilet flushing and irrigation of landscaped areas.

BUILDING ENVELOPE

The proposed timber construction meets high insulation standards and the highly optimised building envelope ensures very good thermal insulation in winter. The principle of a ventilated façade combined with external solar shading provides very good thermal insulation in summer. Extensive green roofs, combined with green roof photovoltaic systems, improve the thermal insulation of the roof in summer.