During 2014 and SEE-Change visited the Chifley Passivhaus’ as part of our Sustainable House ‘over the back fence’ Tours.
So what are the features of these houses?
Harley has built two houses, one behind the other. The house at the rear is accessed from the side as the houses are on a corner, both facing north.
Each is a three bedroom house, the front with a double garage and the rear one with a single car garage. The rear house is the mirror image of the front house apart from the garage.
Both have been built to Passivhaus standard and Harley, the owner, has finally been given certification for his two houses by the international certification body, the Passivhaus Institute in Germany. This means that he has two of only 6 houses certified in Australia to date. This is a demanding certification process and Harley can be duly proud of his achievement.
For more details visit: www.h3space.com.au/chifley-passivhaus
Walls: are Structural Insulation Panels but are covered on the outside with Matrix Scyon cement sheets so are not visible. There is an air gap behind the cement sheets.
Windows: are tilt and turn uPVC from Germany 6/16/6mm double glazing with Argon and low e coating inside (surface 3). Conductivity is 1.3 for frame and 1.1 for the glazing. All seals are compression. Window sizes in bedrooms are smaller than conventional but bring in sufficient light and warmth from the north. Five small windows are on the south and one on the west of the front house, and presumably on the east of the rear house. Front entry and rear laundry doors are both double glazed with the same configuration as the windows.
Insulation: 150mm XPS R3 under the slab, 300mm EPS roof, 90mm polyisocyanurate foam (PIR) R4 in walls.
Thermal Bridging: Slab floats above ground, no contact of any building envelope element with the ground.
Heat Recovery Ventilation System (HRV): This runs continuously bringing in fresh air, which is recovering 95% of the heat from the exhaust air. This keeps the house dry, comfortable and smell free. The inlets are inserted in a bulkhead above the northern windows and the outlets are opposite in the service rooms and kitchen. This enables the main living room door to the hallway and the main bedroom to be closed without interfering with the air flow. Air from the main bedroom is drawn through a small air vent to the walk in robe which then vents to the ensuite where the exhaust is located. (Refer to image below).
Lighting: All lighting is LED downlights in bulkheads or lowered ceilings or LED’s in pendants on power rails giving flexibility to the lighting arrangement. Service area lighting is proximity activated with no obvious switch on delay. (Refer to image below).
Hot Water: A Sanden CO2 hot water system is installed and working. The heat pump compressor noise is lower than any other heat pump I have ever heard; hardly noticeable when conversing next to it. The tank is located in a service cupboard next to the HRV in the Laundry; the heat pump is outside the Laundry door. Moisture from a drain in the heat pump has been allowed to drain onto the concrete. (Refer to image below).
Heating: (if ever required) is a 1.2kW electric element in the HRV outlet duct. Harley calculated from the Passivhaus program (PHPP) that no more than this will ever be needed. (Refer to image below).
Cross Ventilation: Windows are located opposite doors to allow cross breezes to flow through the rooms. Windows in the main bedroom have windows in the ensuite and walk in robe opposite.
Floors: All living and service areas have ceramic floor tiles, not sure about bedrooms.
Rainwater: Drains from the slightly inclined roof to three metal tanks at the rear approximately 2000L each through large guttering. Overflow pipes from the tanks drain to the stormwater outlets. (Refer to image below).
Shading: External see-through screens are to be fitted soon to the northern windows to regulate the heat entering the house because in winter there can sometimes be too much heat entering the house. The eave should overcome direct radiation in summer but the screen will help with diffuse radiation. This problem will lessen when a garden is established.