Choosing passive house
RD Rýmařov has designed this passive house with diffusion open structure on the basis of the standard house project Kubis Lumio.
RD Rýmařov, the biggest Czech producer of wood structures, commenced works on this energy passive house with diffusion open structure on 9 November 2009. The building was finished on 18 December of the same year and the investor could happily move in before Christmas. It is based on the standard house project Kubis Lumio and the structure of its parameter and roof components meets all requirements for an energy passive house.
Even the standard version of the house (Kubis Lumio) from RD Rýmařov production brings together modern architecture with the current requirements for a functional interior layout. The upper floor is not restricted by sloping ceilings and therefore offers the same usable floor space as the ground floor. Two aisle roofs with the skylight create an untraditional lighting of the staircase. The investor gains a large living area inside a small house thanks to the modern architectural design of the building.
When we add the remaining attributes typical for houses from the production of RD Rýmařov i.e. speed of construction, affordable and guaranteed price, thirty-year guarantee for the construction system which is even in its standard version already low-energy and characterized by a high sound insulation, variability and possibility of individual adjustments, we have a house that attracts anybody who likes the current trends of individualised living. The investor, Mr. Otakar Jiránek, the director of Country Life (owner of vegetarian food eateries and shops offering organic products) is not an exception. His corporate headquarters, also known as “The Ark in Nenačovice”, was the first house in the Czech Republic which was built to meet the passive house standards.
And it is a new house based on the standard project Kubis Lumio that Mr. Jiránek will move into this Christmas. His new family house will be, not unlike his company headquarters, a pioneering venture once again. It will be a passive family detached house based on a standard house project. This fact is essential, especially at this time when a lot has been said and written about passive houses. As there are not many of them, a plethora of myths and half-truths is associated with passive houses – a situation resembling the state of things around wooden houses several decades ago. And it is RD Rýmařov as the leading producer of wooden houses in the Czech Republic who establishes its leading position once again by showing that passive houses can be constructed as standard projects without excessive demands on the budget and that they are affordable for anyone wishing to live as energetically efficiently as possible.
In what aspects does this passive house differ from the standard version Kubis Lumio? Visible changes in size and internal structure which reflect the individual needs of the investor can be seen at first sight. The ground plan of the house is 13.5 x 8m, so the house grew in length and width when compared with the standard project. By enlarging the built-up area, the total useful space of the house has been extended too. It stretches over two above-ground storeys (there is no basement) each of which accounts for 83.5 m2, i.e. 167 m2 in total.
A less visible but very substantial change to achieve the parameters for passive house standards is the design of structures. For instance, the width of the exterior walls in a standard house is 265mm and the heat transfer coefficient is U = 0.18 W/m2K, whereas the non-standard version features width of 387mm with heat transfer coefficient U = 0.14 W/m2K. The envelope of inner and outer walls is made of FERMACELL fibre-reinforced gypsum panels, the passive house, however, also uses FERMACELL VAPOR vapour insulation gypsum boards which are a part of the open diffusion construction of the house. Another major innovation in the construction of exterior walls is the assembly skin wall with fibreboard insulation.
Exterior wall (U = 0,14 W/m2K) consist of:
- FERMACELL 12,5 mm fibre-reinforced gypsum panel,
- 60 mm assembly skin wall with fibreboard insulation,
- FERMACELL VAPOR 15 mm vapour insulation gypsum board,
- 120 mm supporting frame with fibreboard insulation,
- FERMACELL 12,5 mm fibre - reinforced gypsum board,
- 160 mm fibreboard insulation,
- open diffusion facade system.
Roof structure (U = 0,11 W/m2K) consist of:
- 15 mm plasterboard,
- 60 mm suspended ceiling board with fibreboard insulation,
- vapor insulation,
- 240 x 60 x 24 mm rafters with fibreboard insulation,
- nadkrovní tepelná izolace z dřevovlákna 100 mm,
- kontralatě, provětrávaná mezera,
- střešní latě,
- dřevotřísková deska OSB,
- střešní krytina tizanzinek.
Výhodou použité difúzně otevřené konstrukce pro energeticky pasivní dům je vysoká úroveň prefabrikace, minimální náklady na vytápění a chlazení, použití ekologických materiálů, rychlost a přesnost výstavby a po předání investorovi vysoký komfort bydlení. Dům odpovídá požadavkům programu Zelená úsporám a díky tomu může investor žádat při jeho výstavbě o státní podporu. Použitá konstrukce navíc neobsahuje žádné stavební prvky, které by byly zdrojem formaldehydů (jako např. OSB desky), deskové materiály FERMACELL jsou nehořlavé s třídou reakce na oheň A2. První z měření těsnosti blower door testem (zjištění objemu vzduchu, který uniká netěsnostmi v plášti budovy) přineslo výsledek n50 = 0,45/h, což je výrazně lepší než požadovaná hodnota n50,N = 0,6/h.