Demonstration building of the eco²building system: First passive house prefabricated wood building system for commercial and industrial buildings
Starting point / motivation
Commercial buildings emit considerably more CO2 for heating and cooling than residential buildings. The majority of commercial buildings are constructed under the premise of minimum building investments. Expressed constructively and technically, they would be built with a primary structure of steel or concrete clad with for example 8 cm sandwich elements. The roof would be designed with corrugated sheet metal with approx. 6 to 10 cm of thermal insulation on top. In most cases, glazing with a U-value of 1.5 to 2.5 (double-glazing or overhead light glazing) would be used. Expressed as an energy characteristic value, commercial buildings are between 200-300 kWh/m2 and year. Hence, the building standard with regard to the energy efficiency of today's commercial buildings can be compared to the standard of residential buildings around 1960. Energy-saving construction for commercial buildings is still in a pioneer phase.
Contents and goals
The goal was to develop a wooden hall construction system and to demonstrate that it has very low heating and cooling energy demand (comparable to the passive house standard for residential buildings) and simultaneously could be offered in the market as economical and competitive. During the course of the HOLIWOOD project, which was funded by the European Commission using funds from the 6th research framework programme, the project partners developed the eco²building construction system and demonstrated fulfilment of the predefined requirements (energy efficiency, flexibility, sustainability, cost-efficiency, constructional quality, etc.) through technical testing of the main components and simulation of the indoor climate and building physics factors. Hence, the objectives of the project were:
- construction of the first eco²building demonstration project in Europe
- evaluation of the building within the framework of a technical, economical, and ecological assessment incl. monitoring of the indoor climate performance
- optimisation with regard to planning and implementation processes
- dissemination of the project results and preparation for the market launch
- establishment of a product for commercial and industrial buildings that is market ready with 500 to 20,000 m2 of usable space in the commercial building sector.
Methods of treatment
The consortium wanted to use the project at hand to demonstrate that low-priced buildings can have both high architectural quality as well as a very good indoor climate with the associated quality for the workplaces - with minimum running costs. This was to be achieved through:
- a flexible construction system with a high degree of prefabrication and the cheaper prices for labour and material associated with it
- good thermal insulation and air-tight construction for low heating and cooling costs and draught-free workplaces
- high-quality windows for solar yields and good use of daylight with low heat losses
- comfort ventilation for sufficient fresh air and reliable removal of pollutants
- integrated planning and implementation
- overcoming the tendering practice through establishing long-term cooperative ventures and supplier relationships.
The individual aspects and components were known in the field of energy-saving construction. However, in the field of commercial construction, there is still no comparable offer anywhere in Europe. The eco²building construction system is the first prefabricated wood building system in a passive house quality for commercial buildings in Europe.
Expected results / conclusions
The new administration building of "Eine Welt Handel AG" was built in Niklasdorf (Leoben region in Styria). The building was built in an east-west direction at the construction site (Address: Depotstr. 2, 8712 Niklasdorf) between the federal road and railway line. The customer enters the building through a spacious exhibition area on the ground floor. From there, stairs take him to the event and office area in the upper floor. Truck ramps and a direct rail connection to the ÖBB are available for goods receiving and shipping in the warehouse and order picking area.
The pilot project has almost CO2-neutral biomass heating. The ventilation system with heat recovery in the office and multi-purpose areas guarantees a constant supply of fresh air. The roof of the building was equipped for later installation of approx. 200 m2 of PV modules.
The large 2,850 m2 building with an investment of approx. 2.75 million EUR has the following trendsetting characteristics:
- Heat requirement: 15 kWh/[m².a]
- Heating load: 12 W/m²
- Primary energy demand: 64 kWh/[m².a] for hot water, heating, cooling, auxiliary current, office applications and lighting
- Air-tightness, n50-value: 0.30 1/h
- U-value, outside wall: 0.197 W/[m².K]
- U-value, roof: 0.178 W/[m².K]
- U-value, windows (office): 0.9 W/[m².K]
- Costs for hot water and heating: < 2,000 EUR/a
The values that were calculated with PHPP and confirmed with dynamic building simulation are checked through two-year monitoring.
The sustainability of the building from an ecological, economical and social perspective has been assessed with top ratings by an external office by means of life-cycle assessment, life-cycle cost calculation, TQB-certificate (pdf) and klima:aktiv house criteria.