Eco house – Margi and Charlie Madden

1. Orientation of the main living areas towards the north, to allow the sun in in winter, and not in summer.
2. Double glazing to trap the sun’s warmth in winter, and reduce heat gain or loss.
3. Thermal mass to store the heat from the sun in winter, and “coolth” in summer
4. Insulation to reduce unwanted heat loss or heat gain
5. Ventilation

Orientation – the most important aspect of a new build

If the house is due north and the eaves are right the sun doesn’t come into the house in summer except on the east and west sides

Sun’s movement across the sky in winter

As the sun is lower, it comes in the northern windows and warms the floor

Winter sun reaching into the house and warming the floor

 North side of house showing summer sun not coming into the house at all

 Other cities at different latitudes have different angles

 Passive solar heating

1. Windows trap the sun’s heat which passes through glass and warms the room. The room’s heat doesn’t pass out again through glass.
2. Great in winter, not in summer, so most windows face north, and only a minimum to east and west, which get morning and afternoon sun

Windows should be shaded in summer

1. Deciduous trees
2. Pergola with deciduous vines
3. Wide verandahs or eaves, outside blinds

Windows should be insulated in winter

1. Double glazing
2. Curtains on inside

Thermal mass

Brick, concrete, stone and earth take a long time to heat up, and cool down.
They collect and store the sun’s energy in winter and store “coolness” in summer

1. Dark tiles better than carpet or wood
2. Internal brick or stone walls
3. Our house is often 10 degrees cooler than outside (sometimes 14 degrees) on a hot day, and 8-10 degrees warmer on a cold day.

The sandstone wall has thermal mass ie it stores heat in winter and ‘coolness’ in summer. The cement slab also does this. Notice the sun streaming in on a winter day, right across the floor.

Moderately dark tiles chosen to absorb more of the sun’s heat on a winter day.

Easily felt with bare feet

 Insulation and R value – higher is better

-Solid materials transfer heat at a greater rate (have a lower R value) than materials that have air trapped inside them.
-Straw bale walls have an R value of between 8 and 10.

1. Timber framed insulated walls are around R1.5,
2. insulated brick veneer R2,
3. uninsulated brick veneer R0.5,
4. mud brick less than R1.0,
5. rammed earth less than R1.0
6. Pink batts – 2.5 to 6 depending on thickness

Straw bales in the walls held down with tape 

Cement lime render – 3 layers
No paint – just the natural sand colour

 What about fire?

Strawbales once erected and rendered are highly fire resistant.

Setting fire to a completed strawbale wall is like burning a telephone book, as no air can get in.

Testing of rendered straw bale wall by CSIRO

The wooden frame was designed to fit the straw bales neatly between them.

The roof faces north to get the most sun on the solar panels

 Ventilation

 Water

Energy 

Heating and cooling

-Underfloor heating

1. not needed much
2. Heat the lower half of the room not the ceiling
3. warmth at a lower overall temperature
4. 15 percent more efficient than conventional radiators

-Ceiling fans – wonderfully effective
-Reverse cycle air conditioning – not needed much, eg only at end of a hot day
-Ugg boots and jumpers when needed

 Composting toilet

Retrofitting – not everyone can do a new house

1. First stop drafts – the most cost effective change. Door and window seals can make a cold house much better – you don’t have to freeze in winter
2. Turn off standby power – TVs, microwaves, washing machines, phone chargers could be costing you $100 a year – get a special switch that’s easy to reach.
3. Insulate ceiling
4. Change to LEDs or compact fluoro lights
5. Plant deciduous trees and vines to shade the house, eg Boston Ivy

 One 4 person household in Melbourne made these changes and are saving hundreds of dollars per year

1. LED and CFL lighting and fittings: $350 spent, saving $100-$120 a year.
2. Draught sealing: $150 spent for a yearly saving of about $100 in heating and cooling costs.
3. Removable shading: $100 spent to make shades, saving annually $100-$200 in heating and cooling costs.
4. Insulation: $200 spent on missing insulation, for an estimated saving of $30-$40 a year.
5. Powerboards with switches: $80 spent with savings of over $200 a year on standby power not used.
6. Re-usable batteries and chargers: $250 spent for a saving of at least $60 a year.

 Why aren’t we doing it?

- The problem is in our mind. The technology is all there, now.
- Its just a matter of actually doing it.
- Even if you don’t think climate change is caused by humans, we still have a responsibility to the environment and to each other, to reduce pollution and improve energy efficiency
- We can all make our houses more comfortable to live in, warmer in winter, cooler in summer and cheaper to run
- The time is past for excuses like

1. I’m too old, I’m too poor
2. It won’t affect me
3. I’m too busy
4. What difference will one person make?