Eco-friendly house in Sunnybank Hills
This recently completed 300 square meter residence has given Neylan Architecture the opportunity to fully apply smart subtropical design principles along with innovative environmentally sustainable design strategies, thanks to the client’s commitment to a greener and healthier environment. The house is located in a typical suburban area where Architect-designed homes are not common and where buildings generally relay on traditional construction methods with little regard for environmental and energy efficiency issues.
The spatial layout achieves a distinctive relationship to the site by orienting and opening the two-storey house into a north-easterly direction towards a existing parkland. Living and bedroom areas face shaded verandahs, pergolas and decks ensuring a pleasant transition from indoor to outdoor spaces, along with exposure to breezes in summer, sunlight in winter and great views.
An open plan with a reduced building depth, integrated to double height racking ceilings, encourages cross ventilation and efficient air movement. Additionally, elevated south-oriented clerestory retractable louvers provide ample ventilation while allowing heat and humidity relief , along with shaded southern illumination.
Adequate insulation, fenestration and shading complete the temperature control strategy ensuring the house has no need for air-conditioning or ceiling fans, relying solely on natural ventilation.
Notwithstanding programmatic, maintenance and financial constraints, materials with reduced resource depletion impact, low inherent pollution and low embodied energy have been selected where possible. In addition to the use of sustainable plantation timber for structural framing, Australian recycled hardwood flooring is used throughout the house.
For exterior decking and screen battening, an innovative wood composite product made from a blend of recycled wood and plastic was selected. In addition to being a very eco-friendly product and unlike conventional timbers, wood composites do not bend, break or splinter and require no sanding, sealing or painting for lasting protection providing a very low maintenance product. Low V.O.C. adhesives and natural oil sealers were used throughout the building. Zero V.O.C. water-borne paints with low odour and no dangerous chemicals were used in both interiors and exteriors.
The building makes full use of its north facing skillion roofs to utilize solar power. An array of 23 roof-mounted photovoltaic panels with an output of approximately 6000 kW hrs per year are used to generate electricity, while an electric boosted dual-panel solar system provides hot water, significantly reducing both the house’s carbon footprint, and in the long term, the occupant’s gas and electricity bills.
A comprehensive and integrated water management strategy includes provision for rainwater harvesting and grey water recycling. The idea is for both systems to complement each other: while filtered rainwater will be used as the primary supply for drinking, kitchen and bathrooms (hand basins and showers), treated recycled grey water will be used for toilet flushing, gardening, laundry (cold water) and irrigation.
Rainwater collection is maximized by using the skillion roofs to channel water to two 5,000 litres tanks located at the lower garage level. Rainwater is then filtered through a 3-stage process involving cartridge pre-filtration and UV sterilization, ensuring water is safe for human consumption.
On the other hand, the grey water recycling plant has the capacity to process up to some 1200 litres of grey water a day. This unit treats water from hand basins, showers and the washing machine, and then recycles it for the abovementioned uses, representing a substantial saving of potable water of around 100 litres of drinking water per person a day or an annual saving per person of 47,000 litres.
Unfortunately as this technology is new to Queensland and to the Brisbane area in particular, gaps in Council legislation prevented the grey water recycling plant from being properly assessed and approved, and therefore could not be installed upon completion of the building. As a result, provisions had to me made on site for later retrofitting the system once statutory and compliance issues are addressed.
To complete the energy saving and water management strategy, 4-Star WELS rated plumbing fittings and compact fluorescent energy saving lamps, along with 4 and 5 –Star Energy Rating appliances, are in use throughout the house.
Overall, the eco-friendly Sunnybank Hills residence is the product of a coordinated ESD effort which starting with the client, and integrating all architectural, engineering and building processes, renders and innovative building that dares to make a statement in a difficult suburban context where environmental awareness is in its early days.