What does one do with a 50-year-old red brick residence in Far North Queensland that comes complete with a two-star energy efficiency rating? Many things, energy experts say.
While the highest available rating for energy efficiency is 10 on the Nationwide House Energy Rating Scheme (NatHERS), the average Australian house still carries a rating of 2.2 stars and elevates to 4.9 stars after renovation. Renovating in just the right way could slice heating and cooling expenses by up to 50 percent.
A good number of Australians are renovating their properties during the pandemic and in accordance with the extension of the Home Builder Grants Scheme, with CSIRO building experts insisting that it is an ideal opportunity to elevate home energy ratings.
Adam Fletcher and Kim Seccafien of Cairns opted to treat their Queensland home to an affordable retrofit that elevated their energy rating to about eight stars.
The pair’s power bill has descended from several thousand dollars a year to about $800 and they rarely need air-conditioning.
Fletcher, an environmental scientist, stated that the objective was to achieve affordable energy efficiency.
They retrofitted the ceiling with insulation and renovated the walls. They favored the use of ceiling fans, attaining sound ventilation and the energy consumption of a one-person household.
Architect and Griffith University adjunct research fellow Belinda Allwood urged the pair to be creative in their renovations.
She opened the house via a breezeway, permitting them to access their backyard and relocated the bathroom and toilets to an “outhouse style” wet area, creating additional living room.
To renovate for sustainability, Allwood said that one must start by examining a home’s existing conditions for climate capability, then figuring out what is needed to residents to live in comfort—and for less than half the cost of constructing a new residence.
She stated that the home at Edge Hill in Cairns was completed in dual stages. The preliminary budget was $160,000, which covered two-thirds of the work; the total project cost was $200,000.
Allwood counted the home’s structure and red brick aesthetic among its advantages.
Also present on the site was a large yard with planted trees, but the home itself was overheated and not well oriented, with weak natural ventilation and shading.
The home’s original building fabric remained, while the home was ventilated and connected to the sizable back yard. Materials like timber and brick were recycled on-site, insulation was added and openings were created to facilitate cross-ventilation.
This process produced a comfortable, better functioning home—one that came complete with a micro-climate.
Building efficiency experts representing the CSIRO have established an Australian Housing Data website, which demonstrates that the average standing house was rated 2.2 stars for energy efficiency—but post renovation, the rating shot up to 4.9 stars.
CSIRO started an education campaign to align with the continuation of government grants for renovations, including those instituted during COVID lockdowns.
CSIRO research leader Anthony Wright stated their data demonstrated that sound renovations could represent a 30 to 50 per cent reduction in heating and cooling expenses.
Wright offered renovation recommendations on behalf of the CSIRO.
They include sealing up gaps and cracks in the interest of improved ceiling insulation, applying external shading on windows suffering from excessive summer heat gain, updating household appliances, and considering more costly options such as double glazing or underfloor insulation or retrofitting wall insulation.
When it comes to modern renovations, energy efficiency leads to increased comfort for a home’s occupant, and enhanced energy efficiency for the world.
CSIRO scientist and former architect Michael Ambrose stated that the average two-star rating for many of Australia’s older homes was not acceptable by global standards. He said that data now was bring collected from each new home constructed in Australia.
In the wake of renovations completed, people receive a new energy rating certificate, and their home’s new data is collected and analysed.
Almost 800,000 houses are represented in the database, with their renovations recorded—their insulation levels, ventilation, etc; thus providing a sound understanding of what the building industry is doing to attain needed energy efficiency savings.
Australia has established a Trajectory for Low Energy Buildings, establishing a goal for “zero carbon-ready” buildings after 2028.