Passive House Building Products

Passive EcoWall is a building concept designed by Ecological Building Systems, which provides a complete low-energy, diffusion-open design based on tried and tested Passivhaus principles. The concept features the use of Gutex woodfibre boards, Finsa airtight racking boards, and the Pro Clima suite of airtight and windtight solutions. A number of certified  passive houses and modular buildings have already been constructed in Ireland and the UK utilising the Passive EcoWall concept, which delivers significant reductions in energy use combined with high levels of comfort. The specification may also include natural flexible insulation within the timberframe structure, such as Gutex Thermoflex, Thermafleece sheep’s wool, or Thermo Hemp Combi Jute - an insulation made from a combination of hemp and upcycled jute fibres.

The use of more natural materials with minimum embodied energy ensures a significantly reduced carbon footprint. This also enables the Passive EcoWall system to provides a truly breathable structure..  The addition of Finsa Superpan VapourStop, an innovative internal structural board pre-fitted with a vapour control and air barrier layer, increases efficiency on site and reduces installation costs. This provides a robust, continuous, internal airtight seal for the construction.

As structural elements are sealed more than ever to attain higher levels of airtightness, moisture management is essential. This is particularly important in our damp climate.  Unlike many conventional timber frame wall systems which utilise vapour resistant structural boards, such as plywood or OSB externally, Passive EcoWall incorporates a breathable external insulation layer of Gutex Multitherm woodfibre boards. These provide high levels of thermal and acoustic insulation and are also extremely vapour diffusion open. This allows structural elements to dry out rapidly and thoroughly.  In this way, condensation risk is dramatically reduced. 

Passive EcoWall also offers a high degree of flexibility allowing specifiers to amend either the frame depth or Gutex Multitherm insulation thicknesses to achieve a range of thermal resistances, from the Passivhaus backstop of 0.15W/m²K to 0.10 W/m²K.

Passive EcoWall is a perfect example of how it is possible to combine low energy construction with more sustainable building materials, with lower, or even negative carbon emissions. Utilising building methods such as this will be key to not only reducing operational emissions, but the significant upfront embodied emissions which are emitted from the production of building materials.

Passive Eco Wall build-up

This example of the Passive Eco Wall concept, the components used are as follows (from exterior to interior):

• Open jointed timber cladding (up to 30mm gap) installed horizontally over vertical timber battens
• Pro Clima Solitex Fronta Quattro all-black breather membrane. Overlaps are taped with Pro Clima Invis all-black airtight tape; junctions sealed with Pro Clima Orcon F.
• 100mm Gutex Multitherm carbon-negative natural woodfibre external insulation
• 220mm Gutex Thermoflex carbon-negative flexible woodfibre insulation installed between timber joists
• 12mm Finsa SuperPan VapourStop airtight vapour barrier racking board. Joints are sealed with Pro Clima Tescon Vana airtight tape; Junctions sealed with Pro Clima Profil airtight corner sealing tape.
• 50mm Gutex Thermoflex natural carbon-negative woodfibre internal wall insulation within a 50mm service void
• 15mm plasterboard suitable to building regulations for fire and sound requirements

Alternative insulation options include: Thermo Hemp Combi Jute and Gutex Thermofibre. A natural breathable paint such as Auro is recommended for the internal finish.

Typical U-values of a Passive EcoWall (W/m²K)