Architect Ben Walker describes some passive house designs that are heavily internalised, with very limited window and door openings as ‘insulated eskies’.

‘This is a conventional way to achieve “passive” outcomes as the weakest part of the building envelope — usually the windows — become relatively minor elements of the proportion of each wall,’ explains Ben.

His recent project in Turner takes a different approach, achieving a similar energy efficient outcome, by prioritising strategically placed outdoor spaces, framed internally by triple glazed windows.

A challenge for the architect was how to ensure maximum passive solar gain, while balancing the privacy of the house located adjacent to a public park.

In response, the single-storey home has been designed with a U-shaped floor plan with a parent’s zone on the northern side, living spaces on the west side, and children’s zone along the south — all hugging a large central courtyard that draws the eye in.

A second north-facing courtyard adjacent to the street is equipped with operable pivoting privacy screens, to shield the interiors from the street and provide views across the adjacent park in the warmer Canberra months.

‘Although we have very cold winters, we also have fantastic weather and temperatures for a number of months during spring, autumn, and summer and many clients want to have the opportunity to engage with this weather through open internal to external connections,’ says Ben.

A set of north-facing sawtooth roof elements captures further natural light, and can also be opened in summer to assist with ventilation of hot air.

Every element of the house has been designed with sustainability and comfort in mind.

The building utilises a heavily insulated concrete burnished slab, which acts as a passive heat sink by capturing winter sun and re-radiating stored heat during the night.

Walls are made up of a triple layered system that includes a 140mm wide timber frame with high levels of insulation, two air cavities, and double membranes for excellent air tightness.

An internal skin of dry pressed brick also provides good thermal mass and assists in regulating indoor air temperature.

The joinery has been constructed from birch ply — a zero formaldehyde and low VOC product using water based adhesives to remove potential off-gassing.

Additional features include a centralised heat recovery ventilation system (to assist in air balancing, air quality control and condensation management); 35,000 litres of water storage; and a 8.2 kW solar power system.

With an 8-star NatHERS rating, Hackett Gardens House demonstrates that energy efficient homes can still be visually and physically connected to their environment, through appropriately glazed windows.

The design considers long term maintenance requirements, and is adequately flexible to accommodate a changing family over time.

‘In this way there is a multifaceted approach to the delivery of a sustainable project – one that delivers long term benefits rather than just short term tokenistic inclusions,’ says Ben.