Stephanie McDonald reports on a home in the Snowy Mountains whose uniquely shaped roof helps the home deal with high wind loads.
The design brief for the Snowy Mountains House was for a low cost, low maintenance and environmentally conscious building that was also fire resistant. It needed to accommodate an extended family for holiday get togethers and had to be autonomous due to its regional location. Importantly, it also needed to make the most of the extensive views over the Snowy Mountains.
The home is located in a lakeside village around 20 kms from Jindabyne, NSW, and 45 km from Kosciuszko National Park, with the area experiencing extreme temperatures and strong winds.
James Stockwell, director at James Stockwell Architect, positioned the building along the east/west axis for thermal gain and natural light. The siting also directs the narrow façade to the west over a protective rocky knoll and is located in a wind shadow to reduce the wind chill factor and improve the micro climate.
Stockwell also designed a uniquely shaped roof for the building to resist the high winds the home would regularly endure — he designed the roof as a curved, continuous form to enable wind to flow smoothly over its surface.
“Leaning the façade back opened the building up to the sky and mirrored the leaning of the Snowy gum trees, communicating an acknowledgement of the exposed location,” Stockwell says.
“The shape in turn enabled snow to be released and water to be collected. It served as a perfect structural diagram for the dual hold down/hold up roles, transferring loads efficiently to the concrete plinth.”
The curved roof also allows unobtrusive views around and over the building, with the building blending into the environment instead of appearing as an ominous structure in a bush setting.
Bluescope Steel galvanised steel Custom Orb roofing was used for the external roofing. Internally, Mini Orb in a cream colour was used for the ceiling to mirror the inside of an egg, “creating a nurturing and cosy interior”. The internal space is also tied down to buttress fins of galvanised steel and windows are cut out of the form like pieces of a cake and angled to views of the Snowy Mountains and Thredbo River valleys.
“The material is a traditional Australian lining material,” Stockwell says. “It is also good for acoustics as it refracts the sound waves over its undulating surface. It combined well with the plywood wall lining also chosen to achieve a warm, protective quality internally in contrast to the shield-like exterior.”
There was also a geometric relationship between the angle of the fin walls in the plan and the leaning angle of the ellipse. “These needed to be identical in order for the cut edge (barge) of the roof to run in a smooth, perfect rectangle into the fin walls, which you see in the photos of the front of the building,” Stockwell says.
Designing a curved roof was not without its challenges. Stockwell says he encountered challenges in designing a curved room and making efficient room widths internally while also making the tangent of the roof vault meet the inclined walls at exactly the right height for openings.
“The eave was detailed to achieve a seamless transition from the concrete base and side walls to the gutter and roof. Internally, the efficiency of this joint achieved paths for services, the lighting pelmet and flush window opening detail,” Stockwell says.
No protective treatment for the steel was necessary to any of the exterior of the building. This means no maintenance costs and fulfils the client’s brief for a low maintenance holiday home.
The house also incorporates an efficient hydronic wood burning fireplace (Famar Brevetti) that heats water pipes in the floor and hot water, and a 1 kW solar power grid connected system, which makes the home autonomous. Two 13,500 litre tanks collect water for domestic and fire fighting purposes, while waste is treated in a transpiration trench system.
Snowy Mountains House received a Highly Commended in the 2009 BPN Sustainability Awards Single Dwelling (New) category.
