The Lodenareal, home to a former textile factory next to the rivers Sill and Inn, was transformed to the largest residential passive house project in whole Europe. In 2006 the city asked for a city renovation plan, with the main focus on social, ecological and economical sustainability. Finally, three clusters have been built, following the passive building guidelines.
Developed by â€˜Neue Heimat Tirol’ (a city and state-owned development company) and designed by â€˜architekturwerkstatt din a4′ with â€˜team k2 architekten’, the new building provides highly energy efficient homes for low-income residents and is certified by the Passivhaus Institut in Darmstadt, Germany. The ambitions were to create user-friendly and affordable building with low heating and maintenance costs. It should be less dependent on energy companies. Finally, it serves as a good example of how to build nowadays given the present situation on climate change and environmental issues.
The main innovative features are the solar thermal collectors and the ground water for preheating and cooling of ventilation air. Furthermore is the whole building built in Passive house style. The real innovation, actually, is the combination of techniques, the efficient use of a brownfield area and the extra attention on the livability of the surrounding area (green spaces).
Type: Residential, retrofit
Size: 482 apartments (354 rental, 128 owner occupies)
- Savings: 680 tons of CO2 per year (using just 20% of the energy compared to a standard building in this region)
- Energy gain thermal solar collectors: 367.500 kWh/yr (350 kWh/m2)
- Energy gain preheating of ventilation air using ground water: ca. 30.000 kWh/yr
- Energy gain cooling ventilation air using ground water: ca. 80.000 kWh/yr
- Rental price: +/- â‚¬ 370,-/ month for 50mÂ² apartment, including heating, sanitary water and parking lot
Initiative: The city of Tyrol
Construction management: development company Neue Heimat Tirol
dinA4 and team k2
- In all buildings the Passivhaus standard is achieved with an energy consumption of 14,5 kWh / mÂ² usable area and year. The heating demand according to the Austrian Energy Pass amounts to 7 kWh / mÂ² usable area and year, which classifies the project “Lodenareal” in the category A++.
- There are solar thermal collectors which have a size of 1.050 mÂ², and are good for 50% of the warm water demand. The production of heat for heating and warm water is for 80% covered by a wood pellets boiler (90-300 kW). Heating is realized through space heating through the floor. For high demand situations, like during the winter, a gas boiler (82-326 kW) is used. There is one central fireplace serving four stations — one for each building. Per station there is a buffer-vessel of 2500 liter. Also the collectors are connected to those vessels.
- The average electricity demand in the houses is about 35 kWh/mÂ².a or 2625 kWh/year for an apartment with the size of 75 mÂ². The 1050mÂ² of solar panels produced about 530 — 550 kWh/mÂ²*a in the second year of evaluation. That means that the solar power covered 26% of the overall demand in the first and 35% in the second year — in spite of the expected value of 20%.
- Ground water is used for preheating (or cooling) of ventilation air
- A heat exchanger with ground water is taking care of the heating/ cooling of the ventilation air. This step of pre-heating in the winter saves astonishing 30.000 kWh every year, and during the summer the passive cooling saves up to 80.000 kWh.
- Cantilevered balconies utilize SchÃ¶ck Isokorb Type K elements to minimize thermal bridging.
- Green: There is a green space around the complex of about 8.200 mÂ² with a park and a playground for children. North of the complex there is a pier for boots. Furthermore, there is a bridge connecting the two sides of the river Sill which houses a cycle path.
- Nature: The estuary of the river Sill will be redirected to realize a fish ladder/ pass to facilitate fish migration in the future.
The total project costs amount to 52 million euro and it is estimated that the extra costs of bringing the performance up from a standard low energy building to the passive house norm is 11 %, of which 7 % are covered by subsidies and the remaining 4 % difference is expected to be neutralized within a short time span by the large energy savings.
The results have great implications for the country’s energy strategy. The results encouraged the city of Tyrol to formulate Tyrol’s energy strategy objectives, as the demand for space heating is around 40 % of the total energy demand in Tyrol. Neue Heimat Tirol is therefore willing to apply this Standard in many other of its building projects.
In 2005, the city of Innsbruck and the local â€˜architektenkammer’ (architecture chamber) held a competition for housing in the Lodenareal (28.000 mÂ²). Social, ecological, economical and sustainable features were important aspects. The underlying reason is the on-going high demand for reasonably priced apartments in Innsbruck.
Management oft he project was one important part which was executed by the local development company Neue Heimat Tirol. Sustainability is one of the three pillars of the company philosophy. Neue Heimat Tirol plays a major role in various projects with a strong relation to energy-efficiency and sustainability. For a long period of time, this company gained experience in building low-energy houses — so for them the step to passive houses was a logical one.
Reaching the Passive house standard was a shared idea and dream. A cooperative of all participating parties was set up, who took part in different excursions and trainings to accumulate the necessary know-how. Right from the beginning the institute for Passive houses in Darmstadt was contacted and involved in the process. The planning of the whole project and the weekly meetings and workshops, have been just two reasons why this project was completed and successful.
To guarantee a fruitful collaboration, meetings with architects, project managers, specialists and others were necessary on a regular basis (weekly) and started already early in the designphase. But those meetings also enhanced the possibility of all participants to widen their knowledge about sustainable techniques en to use that for further projects. Furthermore, there have been trainings in Vienna, Salzburg, Bregenz, Innsbruck, NÃ¼rnberg and Frankfurt and organized visits to companies producing Passivhaus-parts.
- combined use of different sustainable technics and methods (passive house, solar thermal collectors, ventilation with heat recovery, etc.);
- techniques are easily reproducible;
- extra attention on livability surrounding area;
- use of the knowledge of the market through a competition;
- watching further environmental impact (use of the local market; limit truck rides, etc.);
- carrying out gained knowledge — spread the word.
- looking at the financing aspects, the project could be realized thanks to subsidies from Tyrolean residential housing development promotion;
- focus on low-income residents;
- regular meetings/ acceptance of the importance of sustainable design among all of the participants;
- organizing visits and trainings for experts, project managers, developers and designers