Master Builders is always keen to feature real projects to showcase the excellence of our members’ work, and to showcase this good work as part of our annual and very popular Green Living and sustainability events. This year, we are pleased to welcome the Director of Croft Wootton Construction Pty Ltd, Nick Wootton, a Master Builder Accredited Green Living Builder to the list of presenters. As a keynote speaker at this year’s Green Living Conference on 26^th August, Nick will be talking about his experience delivering a sustainable build at the coastal town of Somers, located on the Mornington Peninsula.

Nick has 35 years in the building industry, the last 20 of which have been focussed on energy efficient houses. Arriving in Australia 11 years ago from the UK, Nick was surprised at the differences in building practice commonplace at that time. Having been heavily involved with Swedish-made energy saving homes back in the UK, he was used to installing features such as underfloor heating, sealing on windows and prefab framing. This was not the case in Australia.

Since that time, however, Australia has narrowed the gap significantly with the introduction, for example, of the 5-star to 6-star rating regulations.

The build in Somers began with a chance meeting four years ago with a prospective client determined to build a home that would be completely off the grid. She was insistent that the build would not include any mechanical features such as fans, heaters or installation of any cooling devices. Details had already been drawn up of what the client believed to be the design for a 9.1star-rated passive house. Even though Nick recognised how special this project was, he also recognised that, technically, it wasn’t yet a certifiedpassive house. Many of the elements were present, but testing might still reveal opportunities to do more.

Nick began the effort to incorporate passive house elements in November 2015 and is expecting a July/August 2016 completion. The three-bedroom house with open plan kitchen/living/dining area has a concrete wall running through the middle to add to its thermal mass. The owner was quite specific about not using Australian hardwood, but once it was demonstrated that Cypress pine did meet the requirements under the Sustainable Forests (Timber) Act 2004 (Vic), she was happy to see it used for the deck and pergola support. Recycled timber was used for the doorsteps.

The stud walls are 140mm thick, bigger than the standard 90mm studs. This gives extra strength to the structure and also allows for two layers of insulation batts in the wall. This not only improves their R rating, but the overlap of joins yields improved air-tightness. R3 batts are installed in the walls and R2.5 cross overlapped with R3.5 batts in the ceiling. Extra attention went into making sure the batts were installed correctly, without being compressed. Nick applied a breathable membrane to the outer wall and a vapour-proof membrane to the internal wall, just under the plasterboard layer.

The owner’s request to install a waffle pod slab presented a challenge, as it wasn’t rated to tolerate the weight of the concrete wall. However, after consultation with the engineer and building surveyor, the solution was to design a hybrid waffle pod slab with concrete beams and piles. This ensured that the concrete mass of the internal wall was correctly and safely supported.

Airlocks were positioned in both the east and west of the house to prevent both heat loss and gain as people entered and exited the dwelling. Areas of potential air infiltration were sealed. The house is now so well insulated that there is now an essential need to provide necessary ventilation. The next challenge for Nick and his client is to solve this problem without resorting to mechanics.

Other features of this woodland retreat include slab-edge insulation around the building, external Hebel power walls, a 6,000-litre water tank, a light-coloured surf mist corrugated roof with air cell insulation, heat pump solar hot water and, towards the end of the build, installation of solar panels and batteries.

 This is the owner’s first sustainable home and Nick is delighted to see her evident satisfaction with the progress so far. With Nick’s obvious passion about building responsibly it is heartening to meet more builders and clients willing to move towards a greener future.

Come along and hear Nick and other speakers at this year’s Green Living Conference on 26^th August.

By Sarah Ford, Sustainability Project Officer

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