A love of nature and the environment has prompted Louise Costa and her family to create and build a passive house in bushland near Rushworth in central Victoria. JOHN LEWIS tells the story.
Seventeen years ago, Shepparton-born landscape architect and artist Louise Costa bought a miner’s cottage on 16 hectares of cleared and grazed land near Rushworth.
A lifelong nature lover, Louise said her friends thought she was crazy buying a property on box ironbark country where the ground was hard, stony and dry.
“They wondered how I could possibly raise a garden in a landscape with no topsoil but I was inspired by the bushland on my doorstep,” she said.
Two sides of the property are flanked by state forest where a large variety of wildflower and shrub species thrive.
“I thought that if I could re-introduce just some of these species back onto my property, I could create a beautiful native garden to live in and I would be encouraging wildlife to return,” Louise said.
“It was the only place I could afford outside Shepparton, but I thought it was priceless and I was desperate to live there. I felt as though I’d finally come home.”
Louise spent more than 10 years digging holes with a crowbar to plant native seeds sourced from a 20km radius of the property. She covered the ground with eucalyptus mulch to stop seeds blowing away.
She created gravel paths and built garden features such as bird baths with recycled materials. To save on water and maintenance, she kept no lawn on her property which she named King Billy Retreat after the last tribal Elder of the Ngoorailum Wurrung who is buried at Murchison cemetery.
The cottage is now surrounded by a garden of carefully selected native plants that blend into the surrounding landscape.
Along the way, Louise met and married Les Pelle and they now have two children.
“This has made life infinitely more exciting and ridiculously busy with less time for gardening and bird-watching,” she said.
“These days I’m likely to rake the paths once a month just for meditation. The plants, birds and animals take care of themselves.”
Three years ago Louise and Les decided to embark on an even bolder sustainable venture by building a new off-grid, all-electric home using the passive house construction method.
“Our miner’s cottage had become too small for the four of us and we wanted something bigger, not to mention more comfortable,” Louise said.
“The miner’s cottage is a glorified caravan — hot in summer and freezing in winter.”
Instead of removing their carefully nurtured vegetation for the build, the couple purchased 24ha of cleared land across the road from their established property.
They decided on the passive house approach after researching a variety of alternative building options including rammed earth, mud-brick and straw bale.
Louise said a passive house required only 10 per cent of the energy used by traditional homes for heating and cooling.
She said the passive house approach involved minimising heat and energy loss by following strict insulation rules in which the entire building is wrapped inside and out in a high-tech, breathable membrane before cladding.
To make sure there are no penetrations of the membrane, all services such as plumbing and electrics are installed in a ‘service cavity’ independent of the membrane.
Ventilation is provided through a system of fans, vents and ducting throughout the building.
Louise said windows were the weakest point in any energy efficient building.
She called windows “gaping holes”, which can be addressed by installing triple-glazed, passive house certified windows.
To reduce their new materials footprint, they opted for low-maintenance, recycled corrugated iron external cladding. They are using reclaimed materials wherever possible — including salvaged windows and ceramic tiles.
The property is about three to four months away from completion, and has so far exceeded passive house standards by passing the ‘blower door’ test, meaning there are practically no air leaks in the entire building.
Louise said she and Les were continually motivated on their environmental journey by their love of nature.
“We are part of nature and feel we are kidding ourselves if we think we can remain healthy and happy while the natural environment declines,” she said.
“In that way, part of our desire to live in a healthy natural environment is completely selfish. We want to thrive, not just survive alongside some suffering ecosystems.
“Our love of nature shapes the way we see the world and gives major importance to creating a healthy environment for the future of our children.”
More information on passive house technology can be found at: passivehouseaustralia.org
THE LOWDOWN FROM LOUISE AND LES
Landscape
Creating habitat and providing reliable, clean water for birds and animals around your home can be the difference between whether they survive an extreme weather event or not.
Lawns are high maintenance and a mono-culture. Reduction or removal of lawns wherever possible creates more space for nature.
Retro-fitting an old building
Upgrade insulation whenever possible and if affordable, replace windows with double glazing.
Use second-hand materials for garden or house projects.
Avoid buying firewood from unlicensed dealers to ensure it has not been stolen from the natural environment. Wherever possible, install an efficient split-system for heating.
New homes
Consider double-glazed windows. Money saved on single-glazed windows will later be spent on heating and cooling.
Consider the practicality of building a passive house.