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Passive House Che

Wyróżniony Przypadek April 2016
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The architectural concept was to design a simple sustainable house having two storeys and integrating this house into a special location: a mature forest in the heart of Suceava.


The building has been developed discreetly around an inner courtyard as well as thoroughly incorporated into its natural surroundings. This natural setting creates a dialogue between the large glazed surfaces and the interior and exterior of the house.


The main element of the design is the fully glazed central part which surrounds the staircase, halls and recreation area. This glass core enriches the perception of space for those inside. Each room of the house, either moving or static enjoys a privileged relationship with nature.


The house was designed and built to achieve the passive house standard climate conditions in northern Romania (Suceava) and is undergoing certification. Energy demand for heating and hot water is an estimated maximum 14 kWh/m2.year (according to PHPP calculations).


The building features a daylight factor of four times higher than the current requirements due to the generous glass surfaces which allow for a high percentage of natural light inside and at the same time, maximize passive solar gains.


The iconic shape of the roof scales up the solar contribution which is used for heating. The working efficiency of solar panels integrated into the roofing has been a decisive objective towards aesthetic adaptation to the environment.


The exterior cladding is made of wooden slats which have been thermo-treated so as to conserve the physicochemical properties best adapted to the northern climate. The decision to use timber cladding was based on the idea of using a material made of organic properties that recover the area of ​​green space displaced by the construction of the house.


The minimal heating needs are covered by a ground-water heat pump. The photovoltaic panels installed on the roof provide the needed electricity which is vital for household consumption. The domestic hot water (DHW) heating is provided by solar collectors and a tank.



Project highlights


Energy concept with innovative passive design

Despite the harsh northern Romanian climate, large window openings were not an impediment in the energy concept. The effective solution was to combine the large glazed areas with a good orientation adapted to each season:

Natural cross ventilation and mechanical ventilation through earth tubes for passive cooling.
Natural daylighting is four times the average for a home of this size due to the placement (orientation) and size of the glazed areas. By incorporating natural daylight into the design of the home, the passive solar energy gain also increases.


Use of sustainable materials

Recycled insulation materials (perlite screed, wood and cellulose fiber), eco-friendly materials (indoor lawn, gravel on roof, timber cladding façade and innovative materials (engineered thermo-treated wood, low carbon concrete, high performance, aluminum framed windows)


Integrated landscape

The vertical natural cedar slats on the facade blend the structure into the surrounding woodland. The staggered volumes increase the shadow effects, which allow for further blending in - as does the reflection of the foliage on the glazed area.

All the trees on the ground were conserved around the physical parameters of the actual construction site as well as maintaining a green area in the inner space/courtyard of the house.

The green area (lawn) in an opened and transparent atrium replaces the vegetation which was removed by the building footprint and doubles the landscape integration factor therefore making the transition from indoor to outdoor very subtle.





Izvoarele cetatii 55, 720032 Suceava (Romania)



Project team


Project management and main contractor:  SC SIBELIUS SRL

Architecture design:  TECTO Arhitectura

Consultants:  ARHCONS PROJECT - ing. Nicu Curcudel (structure) and Bavaria Eco System - ing. Kurt Theiss (energy concept and systems)

Purveyors:  Binderholz (wood structure), Econtech Theiss (heating system)



Time schedule


Construction:  2009-2014

Delivery and inauguration:  2015



Building use


Type of building:  2-storey residential single family dwelling

Plot Area:  1.285 m2

Constructed Area:  250 m2

Usable Floor Area:  190 m2

Treated Floor Area (conditioned):  140 m2



The main floor contains the common area and an open riser stairwell within the central double volume courtyard. This leads to the master suite, a library, a second bedroom and bathroom as well as incorporating a special concept - a net lounge - in the inner courtyard.


Construction costs


Global construction cost:  400,000 €

Cost/m2:  2,105 €/m2



Envelope performance


Intelligent vapor control barriers have also been installed in order to provide effective protection against structural damage due to moisture condensation. These barriers were added as protection on each enclosure.


Envelope (wall and roof):  U-value = 0,11 W/m2.K



Basement floor / Floor:  U-value = 0,12 W/m2.K


Windows:  U-value = 0,63 W/m2.K



Doors:  U-value = 0,10 W/m2.K



Air Tightness Value:  0,40

Building Compactness Coefficient:  0,32

Indicator:  n50 (I4) m3/H.m2 n50 (Vol/H) Q4



Energy consumption


Annual heating demand:  14,00 kwh PE/m2.year

Primary energy need:  89,00 kWh PE/m2.year

Primary energy need for standard building:  111,00 kWh PE/m2.year

Calculation method:  PHPP V7.1 (


Energy systems


Heating and DHW system:  Biomass boiler and electric underfloor heating

Cooling system:  Geothermal (cooling earth tubes)

Ventilation system:  Natural ventilation / Mechanical with heat recovery


Renewable systems:  Geothermal and Biomass (solar PV on process)



Awards and recognitions


Nominated in the category Residential Architecture – Individual Housing and awarded in the Saint-Gobain Prize:  Innovation at Bucharest Architecture Annual Awards - 2015 Edition XIII:



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