This is a new build at Narara Ecovillage on the Central Coast of NSW. Completed in November 2018, the house is the culmination of decades of thinking and learning about sustainable home building.
It is essentially a lightweight timber framed house built on a steep block, designed to rest lightly on the slope. Orientated to the north, it has excellent winter solar gain, while being well shaded from the summer sun. With appropriate insulation in the ceiling, walls and under floor, the house is well sealed (scoring 3.4 on a blower door test) with heat exchange ventilation. Thermal mass is provided by a combination of a small concrete slab and internal brick wall, and 90 sqm of phase change material in the ceilings.
Apart from producing a comfortable, sustainable house for ourselves, we hoped to show that high quality, low energy housing can be built on any block, with currently available building materials, at a reasonable price. It doesn’t need to be ‘special’, or ‘cutting edge’ to be beautiful, joyful and inspiring.
Sustainable features of this home include:
- Plantation H2 treated radiata pine framing timbers, termite proof, renewable, sustainable and grown here in Australia, it requires less energy to manufacture than the majority of other building materials.
- James Hardie Scyon Stria cladding – made from cement composite materials- low in embodied energy and VOC’s and is durable; resistant to fire, moisture, rotting & termites. recyclable.
- 20mm timber cavity battens in combination with the Enviroseal Proctorwrap vapour permeable (Class 4) membrane
- BioPCM M51 Q24 phase change material to reduce peak diurnal cooling & heating loads, aiding in temperature stability. When used as part of an Active System it acts as an efficient thermal storage battery. BioPCM is used as a lightweight alternative to concrete for thermal mass in a lightweight building. This provides similar levels of thermal performance but reduced weight decreases structural requirements. It also greatly reduces the buildings’ embodied energy; concrete is responsible for 8% of global CO2 emissions.
- Sandstone blocks for retaining & landscaping – locally sourced and supplied, sandstone has one of the lowest carbon footprints compared to other building materials. No chemicals are used in its production or processing
- uPVC windows & doors provide excellent thermal insulation substantially reducing energy transfer.
- Viridian Lightbridge double glazing
- Foam filling around the windows reduces air leakage, improving thermal performance and indoor air quality.
- Low voc internal paint products.
- Use of Birch Plywood throughout the joinery and feature entry ceiling – FSC Certified product, minimal processing, fully recyclable as opposed to traditional laminates which contain plastics often used in cabinetry making