In issue 112, ReNew visited John Morgan’s high-rating 9 Star home. John shares the principles that helped him design to such a thermally-efficient standard and shows us his new space heating hothouse.
There were two levels of thinking leading to the design of Galaxy Hill. The first was simply the aim of having a low cost comfortable retirement home. Then it seemed likely that such a home would be a low energy consumption place and that it could make a real contribution to the climate change issue.
This second consideration loomed even larger as it became clear that politicians would be treating the problem as a political rather than an environmental one.
The basics of thermally efficient building design are well known; they have been listed and discussed in books for years. It seems that for some strange reason they are just not generally implemented all together or in full. Perhaps this is due to a tendency to build down to a price rather than up to a standard?
The three principles of thermally efficient building design are GMI.
G: Glazing
Windows are ‘holes in the wall’; glass in the window will generally keep the rain out but heat can pass readily through. We want to keep summer heat out and winter heat in so at Galaxy Hill we have used double glazing. In addition, the windows have internal screens ‘velcro-ed’ across the top to seal against convection and external shutters to add to thermal insulation. We have made sure that the window and door frames actually fit tightly into the wall structure, so there are no ‘leaks’ through mini cracks in the wall.
M: Mass
In particular, thermal mass, where the solid material is there to lock in heat, whether it is also structural or not. Note that the external brick wall on a conventional brick veneer house is non structural. It is essentially just for show. It also allows moisture to seep into the cavity which may be undesirable.
At Galaxy Hill we have built a reverse masonry veneer house. The external wall cladding is in the form of timber laminate with very little mass. Thus it doesn’t retain heat overnight in a hot summer and it keeps moisture out completely!
The internal thermal mass wall stores thermal energy and in the process keeps the temperature stabilised to a narrow, comfortable range.
Find the full article in ReNew 114
This entry was posted on Tuesday, June 28th, 2011 at 11:11 am