In the last 1980s, after designing and analysing
and promoting solar housing for about 12 years at the time, we decided to
be involved in a solar movie that was put together by a TV station to explain what solar
design was in the housing sector. We had developed the solar energy information
centre that was developed to educate and make people aware of the benefits of using solar
energy. And the TV host David Grant approached us to showcase four houses. Those designs
were from a basic design affordable house, up to a luxury design in Dalkeith, which is
a fairly prominent wealthy area in Perth. It showed
that the concept of solar design was truly egalitarian, there was no discrimination
against the rich. No, seriously, it showed that it could be done on an affordable basis
for everybody. Everyone could save energy, everyone could contribute to the reduction
of carbon pollution. Solar design, how to harness that marvellous
resource the sun, and the wind for that matter, to make life at home a little
easier, particularly if you’re planning or
building a new home. The one thing that does come out in the study of four houses
that’s most important is that a light house need not necessarily be a hot house. We
are going to meet the architect of the four properties in fact, Garry Baverstock. But
first let’s call on the four owners to give us their opinions on what it’s like to live
in a house with a solar design influence. Our first house is a small project home in
Bayswater, built as much as a demonstration model as a residence for its
single occupant. It’s naturally comfortable as opposed to
artificial comfort we get in our offices and other places and it maintains
for my comfort, a very even temperature throughout the year no matter
what the extreme temperature is outside. Now to Stoneville in the hills behind Mundaring,
where a retired professional couple have made a total study of solar design.
Well it’s a house that if you work it well, it responds well. If you’re not interested
in making it work, well it won’t do as well
as it could do. You have to close it when its
very hot outside and not leave the windows and doors open, and then it keeps you
very pleasantly cool. Our third house is at Kingsley. A family home
on a block deliberately purchased for its northerly aspect.
Every morning of the year it’s never necessary to turn on a light unless you get up
particularly early but the normal waking time the house is already light and bright as
soon as you get up. The fourth home in our study is at Dalkeith,
The largest of the four and perhaps the most difficult to design.
It’s excellent, and in summer it’s very much cooler. We don’t get any sun in the
house in summer because the solar pergolas are very efficient and they’re angled correctly.
And in winter it allows the sun to come right into the house and warm it up. Of course the
tiled floor acts as a heat bank and it’s always a pleasant temperature to walk on even
in the middle of winter. Now to the architect Garry Baverstock who
explains the underlying aims of solar design. Passive solar houses in temperate
climates can save between 60 to 90 percent of energy bills, and maintain comfort between
18 to 28 degrees all year round. So you’re living in luxury and you’re not having to
pay for it. You’re simply using the weather and the air temperatures to your advantage.
I think once that message gets clearly through then we will see some significant changes
in subdivision design and were going to see some substantial changes in people’s thinking
about how they put their designs together. In a moment we will show just how these four
homes were designed for solar sense, but first we need to understand what happens in the
W.A. sky. Dr Bill Parker in the solar information centre in South Perth explains with the help
of a model. What I’m going to do now is show you the
winter sun pattern. It rises to the north of
east, about 30 degrees north of east and only comes up in the sky to a fairly low
angle and that’s about it. So that’s why we put the windows on the north, to capture
that sun. Summer’s a completely different picture. This is a midsummer day. The sun
is rising to the south of east by quite a long way, and before even 10 o’clock we’ve
had a lot of heat on that side, hence the reason for minimising the windows. But the
dramatic thing is that the sun appears to sit up there in the sky for a substantial
part of the day. And likewise minimising the windows on the west, same thing again. The five major points are put simply, getting
the orientation right so that you’ve got the house that way around on the block, with
the north there. You’ve got the windows right, minimise the windows on the
east and the west, most of the windows on the north. You’re using solid materials
for construction to store winter heat, primarily. You’re providing adequate
ventilation by the placement of the house with regard to the breeze and bringing
the breeze right through, passively. And really the other essential is to minimise
heat flow by insulation for both summer and winter. The houses were all designed by the one architect,
Grary Baverstock. But Bayswater and Stoneville for example vary considerably in size. The basic principles are exactly the same.
Similar glass areas on the north, the same orientation, the same rules of orientation,
the same rules of shading and getting the winter sun in the north from the
windows on the north. But there is one small difference – the collection area is
actually partially on the roof of this house, and we’re able to reduce the glass
area on the north wall and put it to the middle of the house to help heat the south
rooms. The size of the house as it increases means
that you get a greater depth in the north-south direction and you tend to find
that if you don’t do anything about it you end up with a dark spot in the middle of the
house. And usually with modern plans these days, open plans and central kitchens,
it’s a good idea to make that the brightest part of the house not the darkest.
And it also gives you the freedom as you get a bigger house, if you’ve got views
say on the south side of the house, as in this case, you can put some of the living
areas on the south side and allow the winter sun to come through the roof and strike
the floor on the south side of the house.
With bigger plans you get dark spots in the middle of the house and that’s where
skylights, clerestory windows properly designed to shade in the summer and
expose the sun in winter, gets the winter sun back into the middle of the house and
makes it light and bright and airy, whereas it’s usually the darkest in most plans.
So that would be a fundamental difference between the simple plan which is small, and
a more architectural design which is a lot larger usually. The large home in Dalkeith had that controlled
light source in the centre but another flooding the entry hall to the south.
Well that works very well, it allows light to enter the house all the time, there are
no dark holes in the house. But the sun doesn’t
penetrate in the summer because there is an overhang which is sufficient to block the
sun. All four property owners vouch for increased
efficiency in following solar design principles.
Well the electricity bills are minimal, really very tiny compared with the previous
bills that we were paying. We use very little electricity, we use gas, about one
cylinder per six months for cooking only, so it’s cheap.