- Posted Tuesday, 19 September 2017
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- In Articles
I anticipate that our future homes will blend architecture
and thermal technologies. This new thinking should respect time proven or
enduring strategies of design used by our forebears. Our home design will
always need its aesthetic appeal but the use of its space will be clever. The
nature of thinking that regards ‘bigger is better’ and ‘cheap is practical’ is
quite small and dull indeed. Tomorrow will demand clever use of space and
engage insightful construction strategies and materials. In hot climates,
architecture will be a blended design that is aesthetic and functional but on a
knowledge platform of thermal barriers and energy buffers.
Today we have the benefits of modern technology to help us
manage and optimise efficiencies. I suspect that today’s evidence will become
tomorrow’s necessity. But there are some simple technologies from the past that
are the cornerstone for energy smart buildings. Ultimately if it’s costing us
significantly more to live today, it will be with an increasing cost that will
endure and prove to be not quite so comfortable in the future.
Our initial step is endeavouring to orientate our building
in a way where the East and West faces have some level of protection against
solar intrusion through the summer months. Glazing offers light, visual
perspective and permits airflow, but at a tenfold cost of diminished thermal
shielding. We like our windows but more than this, we need intelligent use of
glazing. Judicious usage of glass, extended eaves and screening prevents the
transfer of solar heating. Generic floor plans have no solar orientation nor
consider the best view of the relevant external world of your house block. The
common belief is that our house should be square on the block, however you can
stay within your boundary setbacks with clever design and enjoy a beautiful
home that is a pleasure, regardless of the shape of your parcel of land, its
topography and orientation.
Crossflow ventilation is another important consideration.
Design needs to understand the direction of the prevailing breezes and use
windows that optimise this cooling. Casements, louvres and hopper windows rank
highly. Sliding glass windows are cheap, however understand that half the
opening is fixed glass and effective cross flow ventilation is half of the area
of diminished heat shielding. Thermal mass is also a very important
consideration. In the North, for decades we have been using brick and masonry
block.
Once again this material can be cost effective, however used
on the external walls you will pay dearly for the life of the building.
Materials with a high thermal mass absorb solar radiation and convert it to
radiant heat. The blockwork becomes a heatsink that transfers thermal gain
internally at the cost of using more energy to remove it by air conditioning.
In saying this, materials of high thermal mass can work in your favour, such as
the slab and internal walls. The use of lightweight materials externally
supported by the use of effective insulation and light reflective colours will
go a long way in making your home a lot more comfortable to live in. We are
currently running tests on materials for external walls that perform
exceedingly well.
The use of high internal mass softens rapid temperature
change and acts as a buffer. This should be coupled with the use of judicious
thinking about what materials best serve the house’s enduring functionality,
not simply its aesthetics. Initially it adds a modest cost increase, but it is
unequivocally cost effective if you plan to live in the house you build. The
materials are in fact largely the same, but it is about selecting the right
materials that work best for you, rather than accepting that past practices are
sound.
It requires thought more than additional expense to
construct an energy efficient building. As a broad generalisation, I believe
the additional cost expenditure of such construction would be returned within a
ten year period and continue then for the life of the building. This is based
on today’s energy cost and represents the ‘least case scenario’. Innovative and
well considered building design is foundational. I have defined the basic
strategies only, as being more detailed is beyond the scope of this article.
There are other elements that I will develop in later issues. We are aspiring
to develop a building that sits at a comfortable 24 degrees all year round and
utilises the everyday household appliances, lights and hot water with a zero
energy bill.