Frank and Liv’s House 2015

Frank and Liv’s House

Frank & ‘Liv’s Solar Passive House, 15 Hovington’s Road Lower Longley

Situated at an elevation of approx 360 m on a 5 Ha property looking north, this house is designed to ‘passive solar’ principles and faces north with an insulated polished concrete floor slab to living areas for thermal mass and ‘free’ heat from the sun. Living areas have 2.4 m high north facing windows, framed by substantial Spotted Gum posts and beams, providing maximum winter solar exposure. Shading from summer sun is provided to the glazing by varying roof overhangs. Three bedrooms are also arranged along the north side.

Insulation levels are excellent. Windows and doors are German Unilux triple-glazed units, with Luxaflex Duette blinds to bedrooms for additional temperature regulation. The edge of the floor slab is insulated with 50mm of expanded polystyrene, protected by fibre cement sheet. The underside of the slab is insulated with 50mm XPS generally, and is also insulated from the strip footings with a layer of Hebel blocks.

External walls are timber studs with horizontal battens for R3.0 insulation. The battens reduce thermal bridging and create a space for moisture vapour, from inside the building, to pass out through the vapour permeable wall wrap, condense outside the wall frame, and drain away. All walls are sealed to the slab with polyurethane sealant. The ceiling insulation is R5.0, and internal walls are also insulated.

Externally walls are a mix of painted cement sheet and block-work from floor level to 600 high for bushfire protection. Macrocarpa shiplap board cladding above is orientated vertically, and has been left natural.

LED downlights in the bedrooms allow the ceiling to continue over the light fittings, and the insulation to remain intact. There will also be sealed LED down-lights and extractor fans in the ensuite and bathroom.

While the house will gain most of it’s heat by direct solar gain, back-up heating will be provided by hydronic heating pipes in the slab, with the water heated by a heat-pump unit for additional efficiency (a heat pump can also obtain 60-70% of it’s heat ‘free’ from the air). Domestic hot water will also be supplied via a heat pump hot water unit, with provision for connection to roof mounted evacuated tube solar collectors in the near future.

A standard dual-purpose septic tank and evaporative trenches treat wastewater and sewerage. Roof water is collected in two large Zincalume tanks for domestic use. A third Zincalume tank is to be installed a few metres from the house for bushfire fighting purposes A dam supplies water for the future garden and lawn and watering the orchard and the numerous trees Frank and ‘Liv have planted.

Look and Learn – This house is currently at a lock-up stage, a good time to look at the “bones” of a building and see how it goes together.