While the Hill End Ecohouse is a celebration of light and form, it is also a celebration of the old. Buried in a 19th-Century house on the site was a treasure trove of timber, windows, and doors. Emma Scraggs, senior architect–sustainability for Riddell Architecture, along with architect Davide Gole, saved 95% of the original house and artfully wove it into a sleek new three-story home. When the project was finished, just two small skids of non-reusable materials were discarded.
It’s so easy to bulldoze the old to make way for the new here in America—and evidently it’s also the case in Australia. But it doesn’t have to be that way. Scraggs notes that even with the labor included, dismantling the house and using the materials resulted in about a $55 difference in the price of the house. In other words, it was negligible.
Scraggs adds that the builder, Robert Peagram Builders, has had a long-term commitment to and love of using recycled materials in construction, which helped the process.
“Demolition of old houses to make way for bigger and ‘better’ modern homes has become commonplace,” Scraggs says. “Buildings made of perfectly sound materials are either demolished and sent to landfills, but, more easily with our timber and tin heritage, could be taken off their stumps and relocated or dismantled with elements sold to salvage yards.”
Scraggs emphasizes that the challenges of using recycled materials were far outweighed by the environmental benefits. “We directly used the timber from the old house and the patterned glass louvre blades [made into a leadlight window]. Concrete stumps and slabs were sent to be crushed into aggregate. Windows and doors went to salvage yards.”
While the recycled content of the house is a story in itself, the entire program for the house was demanding. The client desired a house that would be comfortable in both summer and winter and that didn’t rely on air-conditioning. “Natural ventilation is a critical part of thermal comfort in warmer months in subtropical Brisbane,” Scraggs explains. “Because the house is to run off its solar panels and ideally not require extra power from the grid, maximizing natural daylight reduces energy demands for artificial lighting and hence energy demands and the area [and cost] of solar panels.”
The design of the house addresses the subtropical Australian climate with openings maximized to capture cool breezes, sun, and daylight. The house is in two halves, connected by the striking gallery breezeway, which acts as a funnel for fresh air. Large windows provide views of the surrounding river landscape while reducing the need for artificial light. A relaxed lifestyle is encouraged by the open plan layout, and the timber and tin aesthetic conveys a sense of the Queensland character.
The house is fully self sufficient in both water and power and has a monitoring system to measure the use of energy, gas, and water as well as temperature and humidity. This system also provides a carbon footprint for the house. The north-facing roof has 3 kW photovoltaic panels, which generate 15 kWh/day.
The house has recycled polyester bulk insulation and timber frames to reduce heat transfer. Heating is provided by solar gain captured by the light, polished concrete floors, and well-insulated walls. An efficient gas fire provides winter heating to the southern living space, where solar heating is not possible.
A 15,000-gallon rainwater storage system supplies the whole house and garden. House rainwater is pre-filtered, heated by solar panels, and stored in a well-insulated tank. To reduce water waste, a hot water recirculation unit reheats cold water, and graywater is treated and recycled on site.
Recycling is a passion for this team, but what Australians are concerned about, says Scraggs, is the cost of water and energy. “In Brisbane, during the time of design and documentation, we had a long drought and were restricted with our water use. Rainwater tanks were installed in a frenzy, and household water use continues to be low. Graywater diversion to gardens has taken off as we have only been able to irrigate gardens for the last few years with rainwater or wastewater.”
Australian housing is heading toward a greener shade but slowly, says Scraggs. “Many people are interested, but mass construction of housing in new developments still uses new materials, produces large amounts of building waste, and sacrifices passive heating and cooling over aesthetics or maximizing building footprint.”
Australia’s building codes are getting tougher, and a sustainability audit for buildings being sold or rented is required in parts of the country. “It is an exciting time,” Scraggs says. “But I wish the green future of housing could move faster."