This home at 8 Aquarius Crt, Portland Vic is designed by Energised Homes as a fully self-reliant project. The goal of this project is to raise awareness and interest in self-reliant & carbon zero housing.
Energy Rating The house is ultra-efficient with an 8.1 Star house energy rating. This means it uses only 65MJ/m2 of energy to heat and cool per year, which compares to an average 2 Star which uses 493MJ/M2/yr.
In real world performance the house's 8 Star heat pump needs to be used only on cold nights that follow heavily overcast days. During Winter this equates to approximately 25% of nights, and on these occasions uses about 15 cents of heating. This means the house heats and cools itself for approximately $10-$20 per year from electrical energy which is indirectly provided by the house's solar photovoltaic system.
Water Harvesting Systems The entire house roof is connected to 9,900 litres of rainwater tanks which are located both above and below ground. That rainwater is used for the enitre house. Kitchen; Bathrooms; Laundry; Toilets; and veggie garden.
A grey water system filters all waste water from the Bathrooms and Laundry. That water is used for watering perennial food trees and non-edible plants during dry periods.
External Walls The house has 100mm Unitex cladding over a pine frame with R2.5 insulation. The walls are very tightly sealed with joint sealer around all windows, doors, arcs and skirting. All Sisilation is taped together and to window & door frames.
Recycled bricks have been used for the garage walls.
Internal Walls Similar to external walls the internal walls are fully insulated pine frames with 10mm plaster and very low VOC paints. The internal walls are also tightly sealed, with gap filler fitted where possible.
Roof A light coloured flat roof is used, with Air-Cell sarking used in combination with R5 insulation, which gives the house roof a rating of almost R7.
Floors Ground floors are perimeter-insulated polished concrete, and upstairs floors formaldehyde-free timber flooring covered with either pure wool carpet or rubber floor tiles.
A duct runs through the concrete slab to supply the fridge with cold air from the shaded south courtyard of the house, allowing it to operate between 600 - 1,000 w/h per day.
Solar or Wind Power Generation A 1.4KW grid connected solar array provides energy to the house to power all of the house’s needs.
It is estimated that the house will initially save at least $1,600 per year (compared to average household energy use) plus approximately $800 per year through the Victorian Feed-in Tariff.
Heating and Cooling The 8 Star rating ensures that the house requires very little artificial heating and no artificial cooling. Any heating that is required is provided with a small high efficiency heat pump, and its energy use is indirectly provided by the house’s solar array.
Water Heating Three panel flat plate solar heating with electric boost. The extra panel helps to ensure that the electric boost is required in winter only.
Recycled and/or Sustainable Materials The house is built from sustainable materials wherever possible. Choices are also made for internal air quality by using only products with low toxic content.
Special Garden Features The garden is in development, and will be productive (veggies, fruit, chooks, etc) and/or local native habitat using Permaculture principles. NO lawns is the goal.
Going Forward The major goal of this house is to build a house that is able to be self-reliant, well designed, and cheap enough for the majority of new house purchasers, and to inspire other builders to construct similar houses.
The site is located in a typical new housing estate among typical new houses. This is to show that self-reliant carbon zero houses can sit comfortably in the settings that most Australians are familiar and comfortable with.