Office building in Passive House standard

Photo: © Benthem Crouwel Architects Passive House Office in Etrium, Cologne

The tenant of the “Etrium” in Cologne, the international company Econcern headquartered in the Netherlands, has been involved since 1984 with the aim of realizing “a sustainable energy supply for everyone”. In Cologne, a suitable office building now should be built, which reflects the company’s vision of architecture and energetic idea. There should be an innovative office in Passive House standard is established, which is also architecturally sophisticated. The three-storey building covers an area of 3751 m² and can accommodate a total of 150 employees.

Right at the beginning of the planning team was composed of builders, architects and experts involved Econcern. In this way it was considering the beginning of the implementation planning energy building concept are included. Additional challenge for all parties involved in the project was the short project time. Following the granting of planning permission in December 2007, the employees were already receiving the new office building in October 2008.

Photo: © Benthem Crouwel Architects Passive House Office in Etrium, Cologne

The first major Passive House office building in NRW the Etrium needs about 80% less energy for heating and consumes 70% less primary energy than a conventional office building of the same order of magnitude. The lower primary energy consumption has a significant influence on energy costs. These lie at about 20,000 euros per year, this corresponds to about 0.50 euros per month / sqm. Compared with a standard office of the same order of 1.60 € / m² per month gives a monthly energy cost savings of € 1.10 / m². With rising energy prices, this difference is even greater. The Etrium was honored earlier this year by the German Sustainable Building Council () with the “Gold Seal for Sustainable Building”.

Photo: © Benthem Crouwel Architects Passive House Office in Etrium, Cologne

The distribution of air in the floors is disposed below the ceiling air channels possible. The connection points for the assignment of the relevant premises are located on the right and / or left of the air ducts in the concrete ceiling. The distribution of air in the space takes place via a pipe system with fins arranged behind diffusers. The volume flow for heating or cooling the building is adapted to the weather conditions ie hot summers and cold winters, an increased volume per office space is provided. In the transition phase and at moderate temperatures, a reduction occurs. Out of the office and meeting rooms comes through overcurrent elements or air duct ventilation zones on the cluster to the atrium to pass.

Photo: © Benthem Crouwel Architects Passive House Office in Etrium, Cologne

The glazed atrium forms a central part of the center of the passive energy building concept. It fulfills an important function as an exhaust zone, which makes an elaborate ducting unnecessary. Here, a heat recovery rate of up to 95% is achieved. For energy-efficient heating of the building with its 12 individually controllable climate zones, a ground water heat pump (48 kW) is used.

In summer, the groundwater is used for cooling the fresh air. To reduce the solar gain windows facade manner are shadowed by external shading. In the night a cooling of the charged throughout the day massive storage mass is (concrete) that function as heat storage, a up to four air changes.

Client: Friedrich Wassermann GmbH, Cologne

Architect: Benthem Crouwel Architects, Aachen

Renters: Econcern GmbH, Cologne

Energy concept: Ecofys Germany GmbH, Cologne

Build time: 9 months

Inauguration: 8 December 2008

Cost: 6.5 million euro

Area of ??the building: 3751 square meters

Energy consumption: 116 kWh of primary energy consumption, heating energy consumption 11 kWh per square meter

Ground water heat pump: 48 kW

PV system: 32 kWp. Production of 30,000 kWh / a)

Facts and figures

GOLD certification with the seal of approval in the DGNB (German Sustainable Building Council)
Meet the Passive House criteria according to PHPP
Enclosed space: 12480m ³
Gross floor area: 4970 m²
Area: 3752 m² (150 jobs)
Heating demand m² / a: <10 kWh / m²
Primary energy consumption m² / a: 116 kWh (including heating, cooling, electricity, hot water)
Photovoltaic system: 32.4 kW = 30,000 kWh / a
Solar thermal system to heat water
Rainwater cistern for rainwater harvesting for toilet flushing etc.
five times less heating and 70% less primary energy than a conventional office building
Heating energy consumption is less than 10 kWh / m² a, ie, the building can be heated with an energy equivalent of 1 liter of heating oil per square meter