20/01/2012

Skanska finished one of the first blocks of passive houses in Prague

Skanska Reality, one of the most important drivers of passive and low-energy housing in the Czech Republic, finished at the end of the last year one of the first residential buildings in Prague, which meets the requirements of the Zelená úsporám program on passive apartment block. The object is a house E in the project Milíčovský Háj - south, 1st stage, located in Prague 11- Háje. There are 14 aparments in size from 1 + kk to 4 + kk in the house.
Milíčovský háj – south, passive house E.
There are recently only the last 4 free apartments of the size 2 + kk available for anyone interested in new energy-efficient housing. Savings in heating costs of these flats are significant and can reach up to about 65% of the heating costs in a standart apartment. "To test the passive construction of residential house, we decided at the first stage of shell construction of low-energy housing project Milíčovský Háj - south, 1st stage, "said Naděžda Ptáčková, Director of Sales and Marketing in Skanska Reality. To collaborate on building developement were also invited experts from the CTU - e. g. Ing. Jiří Novák, Ph.D., who was participating in the research program supported by Skanska - CIDEAS (Center for Integrated Design of Progressive Building Structures). He was involved in a set of airtightness measures and carried out the airtightness measurements in various stages of building construction.
"The final measurement of air leakage, the Blower Door test, turned out very well. The implementation of passive house standard in the apartment building, cost about CZK 100 000 more than the realization of low-energy apartment standard in villa houses in the same project, "added Ptáčková. As in other low-energy villas project, in the passive house E are installed high-quality wooden windows and every apartment larger than 2+kk has its own ventilation unit with heat recovery connected to the central air supply and exhaust and underfloor air distribution. Additional heating to the required temperature is instead of the convenient radiators provided with the convectors mounted in the floor or on the wall. Relatively large glazed areas on the facade are complemented by an electrically controlled horizontal blinds, protecting dwellings from excessive overheating during the summer.	Airtightness measurement in praxis
The main adjustments to achieve an overall improvement of energy from low-energy parameters to passive standard, consisted mainly of the material changes in thebuilding insulation - insted of expanded polystyrene were used new generation Kooltherm boards. In addition, the developer made minor adjustments in some critical details of the building - such as fillers were thoroughly sealed around all windows, openings, penetrations, expansion joints etc. The building is prepared for the roof installation of photovoltaic panels, to reaches the evaluation A in building energy performance. The values of specific heat demand, achieved due to mentioned modifications, are comparing to the low energy houses in the project almost by 2/3 lower; the consumption of primary energy reached 63% of low-energy house. Comparison of the passive residential building and the house without the use of environmental friendly technologies shows even better results - specific heat demand is almost 1/5 of the needs of a standard residential house, primary energy consumption is only 47% of a standard apartment building consumption. Beside the Skanska Reality the passive houses in Prague also produces the JRD company, which plans to finish a villa house project Pod Altánem (Prague - Strašnice) in April, with 6 apartments. There is already only one apartment remaining free for sale.
Main source: Skanska Reality press release