Timber Frame approach to both Passive House and NZEB.

Timber Frame approach to both Passive House and NZEB.

“The timber frame makes a big difference in performance… It was a lot easier to ensure airtightness early whereas the house is practically finished by the time you are able to test airtightness on a cavity wall-built house.” Mark Stephens, Architect.

With modern house design, we see a lot more design features and large openings which work quiet easily into timber frame as opposed to concrete traditional building methods, which uses a lot of structural steels and more detailing to avoid thermal bridging. With timber frame construction, these issues are eliminated with the use of timber lintels, glulam beams and encapsulated steel structural elements and steel connections using thermal plates. We use blown cellulose in our walls and roof area which fills the voids and spaces between timber frame wall panels.

The architects design included a geothermal heat pump with mechanical ventilation with heat recovery. The timber frame components work well along side mechanical and electrical systems with access for ventilation ducting, service voids for electrical and plumbing – all of which can be designed and planned at the early project stage saving time and money.

The airtightness is also an area that is designed into the structure early on so that air leakage and air infiltration is avoided which can damage the structure.

Long life Structures have over 60 homes build to these high standards, achieving passive house airtightness standards before the nearly zero energy building (NZEB) standards came into effect. These standards now apply to all new buildings occupied after the 31st December 2020. We strive to be innovative and stay ahead of the trend when it comes to building highly efficient thermal envelopes, we are thermal envelope specialists.

If you are interested in reading more of the article on this beautiful home in Mayo, designed by Mark Stephens Architects, you can view it on passive house plus magazine. https://passivehouseplus.ie which now has an online version of the magazine for anyone interested in keeping up to date with these fantastic homes.

Our Wall Specification used in this build:

100 mm rendered concrete blockwork externally with a 50 mm unventilated cavity to pro clima Fronta WA membrane to 9 mm plywood sheathing fixed to 220 x 44 mm structural studs. The walls are filled with cellulose insulation, blown in on site by specialist contractor. This fill all voids and cavities within the timber stud wall. Intello airtightness membrane internally with a 50 mm service cavity insulated with 50mm sheep wool insulation. A 15 mm Gyproc Plasterboard is installed by others internally to the service battens.

U-value: 0.164 W/m2K (accounts for studs & battens)

The Roof Specification for this project in Ballina:

Alkor fully bonded PVC with seams, with Novaplex coated steel soffit and fascia, followed beneath by 18 mm plywood sheathing, 38 mm ventilated cavity, pro clima Solitex Plus membrane to 300 mm timber I-joists fully filled with cellulose insulation, Intello airtightness membrane, 50 mm uninsulated service cavity, 15 mm Gyproc Plasterboard.

U-value: 0.136 W/m2K

Materials:

With our fabric first build system we use green materials for our walls and roofs. Wood for the timber frame is FSC and PEFC certified, sourced from environmentally responsible forests. Walls and roofs and densely packed blown cellulose insulation. We provide sheeps wool insulation to be installed at a convenient stage of the builder/client.