Passive wood house in Ljubljana

Ljubljana, Slovenia's capital on the River Ljubljanica with a population of just 290,000, is considered the green capital of Europe, with mountains and sea almost on its doorstep and the Slovenian Alps just an hour's drive away. The single-storey wooden house designed by BIRO GASPERIC architects blends harmoniously into the wooded surroundings of the small village of Trzin, ten kilometres north of the city. The passive house's low energy consumption is achieved using sustainable wood fibre insulation materials from Gutex.

Construction table
Project	Passive house near Ljubljana
Client	private
Planning	BIRO GASPERIC architects, Ljubljana
Version	Bauta, Cerklje na Gorenjskem
Gutex products	GutexThermowall, Gutex Thermoinstal, Gutex Multiplex-top
Photos	Miran Kambič

This house, with 218 square metres of living space, impresses with its unusual facade of vertically-mounted larch battens turned through 90 degrees. Its timber frame, fully vegetated roof and energy consumption of just 14.7 kWh/(m2a) make it a particularly sustainable building. To achieve passive house standards, the exterior walls, interior rooms and roof were insulated with environmentally-friendly wood fibre from Gutex.

External insulation

Behind the suspended larch facade, a homogeneous 80 mm thick wood fibre insulation board insulates the external wall with Gutex Thermowall. With a nominal thermal conductivity λD value of 0.040 W/mK (German reference λB value of 0.042 W/mK), the wood fibre insulation board provides optimum thermal protection in summer and winter. At the same time, it ensures a pleasant, moisture-regulating indoor climate and high levels of sound insulation.

Interior insulation

Internal insulation is provided by Gutex Thermoinstal 50 millimetres, mounted on wooden frames with an intermediate layer of wood wool insulation and covered with an ecological clay-based plaster. Gutex Thermoinstal makes it possible to create installation plans for cables and pipes, reducing thermal bridges compared with the insulation normally used in lath constructions. The wood-fibre insulation panel is laid over the entire surface, without any gaps, on the inside of the timber-frame construction. Service ducts can then be milled into the wood-fibre insulation panel.

Roof insulation

The roof is covered with a layer of hard-wearing sedum vegetation, beneath which is a drainage layer with water reservoir and bituminous waterproofing. Gutex Multiplex-top wood-fibre panels were used as a ventilated, water-conducting second layer, laid on rafters with between-rafter insulation made of flexible wood-fibre insulation materials. With Gutex Multiplex-top, a rainproof sub-roof can be created - from a roof pitch of 15° - thanks to the special tongue-and-groove profile of the panels. There is no need to overlap or glue the normal panel joints.

"natureplus" certification

Gutex wood-fibre insulation panels provide optimum thermal protection all year round in the various areas of application, ensure a pleasant, moisture-regulating indoor climate and guarantee effective sound insulation. All the wood-fibre insulation materials used in this project are also recyclable and harmless from the point of view of construction biology, as confirmed by the "natureplus" certification.

The façade is made up of larch battens mounted vertically and rotated through 90 degrees, while the exterior walls are insulated with 80-mm thick Gutex Thermowall wood fibre panels.

In living rooms, Gutex Thermoinstal wood fibre panels ensure a pleasant room climate thanks to their open diffusion properties.

To achieve the passive house standard, the exterior walls, interior rooms and roof of the timber frame have been insulated with environmentally-friendly wood fibre from Gutex. The wood fibre panels used are recyclable and harmless from the point of view of construction biology, as confirmed by the "natureplus" certification.

Thanks to their high dimensional accuracy, the large-format wood-fibre insulation boards could be installed quickly and accurately, and were simply cut on site using a standard insulation saw.

With Gutex Multiplex-top, rain-resistant wood-fibre insulation can be produced from a roof pitch of 15° thanks to the tongue-and-groove profile and low installation height. There is no need to cover or glue the board joints.