Greening the renovation saves money
by Geraldine Hinter
Home
renovators looking at extending or making improvements to their
homes should take advantage of some expert "green" tips for
renovating,
to save money now and in the years ahead.
UniSA Associate Professor in Environmental Mathematics, John Boland is an authority on energy efficient housing and how the weather can support a comfortable home environment.
"Adelaide has the perfect climate for indoor and outdoor living, enabling us to take advantage of the natural light, comfortable outside temperatures and the environment around us," Prof Boland said.
He recommends that when moving into a home, people take the time to examine what’s happening in the home and its surrounds, rather than renovating straight away, as temperatures and conditions vary from place to place.
"We need to think about vegetation, ventilation, the operation of the house and orientation of new rooms so that we can take advantage of the climate and any gully or sea breezes in our renovation planning. If we can lower the demand on heating and cooling first, then we can increase the flexibility of supplying the remaining demand," Prof Boland said.
"People who build large homes that take up most of a building block can’t take advantage of ventilation and natural heating as it takes away their flexibility and adds considerably to heating and costs. This growing trend reduces the available space for vegetation that provides natural cooling for homes, unlike pavers, which generate considerable heat around the home. And if you’re not convinced, try walking on the concrete or pavers with bare feet on a hot day," he said.
Prof Boland recommends that garden designs be integrated with house designs, ideally with small houses on big blocks.
"Trees around houses can be placed to help with climate control, providing shade from summer sun, protection from hot summer breezes and wind breaks for cold winter breezes. Evergreen trees on the western side keep houses shaded from the full summer sun, while deciduous trees to the north allow sun to enter in winter to provide warmth," he said.
"Security screens for windows and doors enable cross ventilation of homes, allowing cool air in and hot air to escape. Access to gully or sea breezes enables even greater cross ventilation opportunities without relying on airconditioning.
"Adelaide’s Botanic Hotel is an interesting example of the use of
a cooling tower for ventilation, which is based on the principle
used by the Persians some 2-3000 years ago. Vents in the cellar
allowed air to enter, where it cooled and then flowed through the
hotel and as the air heated and rose, it escaped through a small
tower on the roof. Now, unfortunately this form of ventilation has
been blocked off and the hotel is airconditioned instead,"
he said.
Depending on the orientation of the home, Prof Boland says double-glazing can improve energy efficiency by cutting conduction dramatically. If double glazing is not an option, single glazings can provide some extra protection against conduction. Outside blinds or awnings also stop heat from entering homes through windows, unlike indoor curtains.
Rather than using old forest growth timber like jarrah for floor joists, Prof Boland suggests using plantation pine timbers laminated with glue that has been impregnated with an anti-termite material.
"This allows us to put termite control within the building materials rather than having to use termite sprays," Prof Boland said.
"Building materials like Hebel blocks or aerated concrete panels have insulating properties and some heat storage. By insulating the interior walls of a particular room, houses can be zoned to heat or cool just one room," he said.
"Building reverse brick veneer walls (brick inside and insulated cladding outside) where needed to stop the heat transfer from outside for areas used in the daytime during summer are another good solution for climate control when renovating. In bedrooms one could consider using insulated weatherboard, which enables inside temperatures to drop dramatically for comfortable sleeping."
Prof Boland recommends no more than a gap of 11 degrees between thermostat settings and outside temperatures in summer.
"Getting used to varying temperatures at different times of the year is much healthier than keeping the body at fairly constant temperatures, which can lead to ill health."