Sustainable House Day, Cloverlea, Victoria

Paul & Merrin’s Sustainable House   Why did we have sustainability as a criteria when building?

An eye to the future. We assumed utility prices, and particularly electricity, would rise at a rate much higher than our income. If we invested now, we would reap the benefits later.

 

We were approaching retirement age. Looking at the experience of our elderly relatives, we knew we would need a low maintenance house that was easy to heat in winter and cool in summer.

  What are the main design features of the house that make it energy efficient?

Kept the house small – big enough for our everyday living needs, but no bigger. This also kept it affordable.

 

All living and sleeping areas face north; utility areas face south. Minimized windows on western side.

 

Wide eaves prevent sun from hitting glass in summer, but allow it to warm the rooms in winter. Slate floor in living area captures warmth from sun.

 

Masonry inside all external walls (low quality bricks) provide thermal mass to absorb the sun’s energy (similar to the effect of a double brick house). ‘Smoothes’ the effect of high and low temperatures. Helps the house stay cooler in summer and warmer in winter. Sometimes referred to as an ‘inside-out’ house.

 

Tromb wall provides some heating for study and spare bedroom in winter.

  What are the sources of water and power?

Water supplied by rainwater tanks.

 

Grid interactive solar system provides electricity. System consists of 18 x SX80 photovoltaic panels (purchased in 2002 at cost of $1500 per panel) and 3 x BP3165 panels (added in 2007 at cost of $1600 per panel) connected to a Sunnyboy SB2500 inverter (cost $3800). 

 

System generates approx 2000 kWh of energy per year, and we use slightly less than that, so our normal electricity bill consists of the supply charge only.  

 

Hot water is supplied by a solar hot water system supplemented, particularly in winter, by a water jacket attached to our wood cooking stove. We have an electric booster on the hot water system for those hot, cloudy days, but we rarely need to use it (twice in 5 years).

 

Wood for the cooking stove and heater comes from our own woodlot, from which we harvest and replenish a small section every year.

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