Sustainable House Day, Nelson, VIC

New Build: Purpose designed and built by owners

Overview
The aim was to build an energy efficient home, self-sufficient in electricity generation, which complemented the rural setting.

The land, ~115 acres, was purchased in 1991. While the property abuts the Lower-Glenelg National Park at the time of purchase it was predominantly open paddocks with almost no trees. The owners have carried out extensive tree plantings of native species to encourage wildlife. While revegetating the property and managing some areas for sheep production the owners lived in a shed which they built in 1996 prior to constructing the main home that was built over an 18-month period and completed in 1997. The 2-bedroom home with open living area and office was architect-designed, with an emphasis on sustainability and energy efficiency, but constructed almost entirely by the owners (including electricity and plumbing) one of whom is a qualified Green Builder. The house is constructed of Mt Gambier stone (low embodied energy and excellent thermal properties), utilises a concrete slab as heat sink/source, and is double glazed.  Orientation and positioning of eaves maximises passive heating.

The house is set on top of a hill surrounded by rolling hills and view s to the ocean. A windy location, the property generates 100% of its own power with two wind turbines and solar panels.  This includes the power necessary to run a filtered in-ground pool. The house garden has been planted with an orchard, herb and vegetable garden. A pond has been established to attract frogs. On the hill above the house are a windmill and a rainwater tank supplying water to the house via gravity.

In 1998 the home won an energy efficiency award from the Glenelg Shire Council.

Water Harvesting
Water is harvested from 2 rainwater tanks. The house is all on rainwater, except the toilet which is on bore water.  The swimming pool is on bore water. All waste water is treated via a septic tank system.

External Walls
Predominantly Mt Gambier stone and brick construction.  RMax insulation in the cavity walls.  

Internal Walls
Mt Gambier stone, low embodied energy and excellent thermal properties

Roof
Zinc alume

Floor
Polished concrete with dark grey pigment and lacquer to act as a heat sink/source.

Window Treatments
All double glazing with blinds and eaves and verandas.

Electricity Generation
Power is generated by two wind turbines (1000 w Bergey and 900 W whispa wind turbines) and several blocks of solar panels (1000W on house, 600 watts on shed).  A diverter which allows excess electricity to be dumped. Three systems are currently used
A 24 volt core system supplies the home and work sheds– 24 Volt DC fridge, freezer, water pump, stereo. Inverter is located in the house.
A 12 Volt system for small appliances such as radios and a weather station.
A 48 Volt system supplies water pump filtration system for pool.
All appliances can be isolated and turned off to prevent them draining power from the inverter, allowing the inverter to stay in standby mode.  If required a diesel generator provides back up power to an 80 amp Battery charger for the 24 volt battery system.

Heating and Cooling
Passive cooling cross ventilation, with a door into patio area to allow cross flow of wind, ceiling fans.
Passive heating with passive solar design and high thermal mass.

Water Heating
Water jacket next to fireplace and also solar collectors – Beasley Roof master and gas booster system (bottled gas).

Appliances
LED and microfluoro lights.
24 DC fridge and freezer.
Transport – electric bike is charged off the 48 Volt system at the pool