Sustainable House Day, Malvern, Victoria

  This late 1800s weatherboard home has been retrofitted with sustainable features such as solar power and rainwater harvesting. The home has ceiling, wall and underfloor insulation and double glazing to maximise heat retention in winter and minimise heat gain in summer.  

Renovation of existing weatherboard home

Sustainable Elements featured in this home

Water Harvesting Systems Collect water from all downpipes using a sump pump located at the stormwater outlet. In this way all rainwater on the roof is captured and there is no need for additional pipework at the downpipes. A 3000 litre slimline tank is used to service the toilets and laundry.  

Garden Features Drought tolerant native plants are used to minimise water needs and attract native fauna. No potable water is used on the garden; in the summer a bucket is used to collect water in the shower to feed small plants.  

External Walls   The walls are clad in weatherboard with sarking immediately behind the boards to act as a moisture barrier and reduce reflective heat gain.   Foam has been injected into the wall cavities to provide insulation equivalent to R3. This method of wall cavity insulation eliminated the need to remove weatherboards or plasterboard and, by expanding in situ, minimises the likelihood of gaps in the insulation.    

Roof Light coloured Colourbond, Two layers of bulk insulation gives an equivalent of R7 to retain winter heat.  sisalation reflective foil has been installed below the rafters to reflect summer heat away from the building.  

Floor Aircell ‘permifloor’ fitted where possible to provide winter insulation of R1.9.

Window Treatments Paarhammer double glazing with low-emissivity glass giving U2.2 and solar heat gain coefficient of around 0.2 (minimizing summer heat gain). Wood frames minimize conductive heat losses and high levels of sealing minimize air infiltration. One window uses ClearComfort film over the existing single pane window.

Solar or Wind Power Generation 1 kW on-grid Kaneka amorphous silicon (thin film) solar system with SunnyBoy inverter provides around twice the homes power needs on sunny summer days and around a third on typical winter days.

Heating & Cooling Heating is provided by a gas hydronic heating system, with a thermostat set to around 19° (lower at night). Heatcharm wood heater used as an alternative heat source. Split system air conditioning is installed, but used only for short periods on extremely hot days. The house will typically have an internal temperature below 30° even on 40° days.

Water Heating Instantaneous gas system.

Appliances The owners have thought carefully about the selection of electrical appliances and lighting. Efficient appliances have been selected wherever possible. Halogen downlights have been replaced with compact fluorescents (CFL) and LED alternatives used for remaining spotlights.

Transport Close to public transport and services (such as shops and medical facilities). Most facilities within 10 minute walking distance or short bike ride. Small car used infrequently for longer trips, or where loads need to be carried.