Sustainability case study: Dalkeith House

Dalkeith is an old suburb of Perth, surrounded on three sides by the Swan River and home to some of the city’s finest old mansions. This residence shares a street with hundred-year-old bungalows and questionable modern-day interpretations of past and international styles of architecture. Our project challenges this context and the contemporary desire to exhibit power and status through architecture. Mostly concealed behind an existing street wall, the project quietly addresses the street while unfolding a controlled sequence of spaces that engage with a hidden garden.

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The scheme uses every part of the property, dismissing the idea of a front and back garden.

Image: Peter Bennetts

We explored the relationship between house and garden by adopting a set of elements developed in a past desert community centre project – a platform, pavilions and parasols. We also introduced a new element – parasites. These four interact to configure the site flexibly, using every part of the property and dismissing the traditional notion of a front and back garden. Site organization is the beginning of a collection of low-tech, cost-effective environmental devices that are bound by the architectural intent, generally concealed from view and denying the contemporary and popular image of a sustainable house.

Perth is the third windiest city in the world and the pavilions are articulated to allow wind to penetrate deep into the house. The wind is cooled by shallow ponds adjacent to the low-level windows, while hot air is drawn out the top of them. The articulated form increases the roof area and potential for water catchment; all roof water is stored in a sub-surface concrete tank under the front garden and supplies both the pool and the house. Water is heated by a solar hot water system with back-up gas instantaneous heater and sun-heated pipes mounted on the roof. Water consumption is minimized through low-flow fittings and the entire house is set up with grey water recycling.

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A double-height outdoor room mediates the temperature of both the upper and lower levels, with automatic blinds shading the house.

Image: Peter Bennetts

A double-height outdoor room has been created, which mediates the temperature of both the lower and upper levels. Automatic blinds temper sun penetration. The blinds double as a projection screen, transforming the outdoor living room into a theatre under the stars. Roof-mounted photovoltaic cells provide power, while consumption is minimized with compact and T5 fluorescent light fittings and low-energy fixtures. The PV cells, parasol roof and hot-water system shade the roof to reduce heat build-up. Winter heating is provided by the direct-sun thermal heat gain of the concrete platform, supplemented with ethanol fireplaces and sub-surface, in-floor heating.

The house is constructed from plantation pine and the cantilevers from plantation plywood. Use of steel and other high-embodied-energy materials has been minimized. The house is clad in a composite, fire-rated panel with sheet steel exterior and an acid-free recyclable core, providing superior thermal performance and minimal material waste. Materials are mostly screw-fixed rather than nailed to increase the capacity for future reuse.

Read a discussion on sustainable site strategies here.