Architecture that makes good use of the sun's energy and incorporates other sustainable features is being celebrated.

More than 30 years after Solar House Day was first held in the ACT, the Australian Institute of Architects returns to a midwinter event to recognise, celebrate and demonstrate the work of local architects and their climate-appropriate energy-efficient housing for the Canberra region.

Solar House Day will feature architects' contributions to the development of energy-efficient passive solar and sustainable house design that responds to its climatic environment.

The Solar House Day lecture will be held at the Shine Dome on Wednesday, July 23, from 5pm. The Solar House Day bus tours will be held on Sunday, July 27 and August 3.

The public is welcome to attend the lecture and tours. To book, please email act@architecture.com.au or phone 02 6208 2100.

These houses, and others to be featured, will be included on the Solar House Day bus tours.

The Beehive, Bungendore
Eric Martin & Associates
Photographer: Eric Martin

A heritage-listed inn, built in 1859, was in remarkable original condition but had the kitchen in the backyard and separated from the house. The building has thick walls and faces the street which meant it was cool in summer but gained no benefit from the sun and was cool in winter. A new kitchen was proposed to provide northern orientation to some living spaces, design for passive solar and to incorporate many energy efficient details, including double glazing. Th edge of the slab was insulated and extra insulation was put in the walls and ceiling.

A specially designed “hot box” was also built to benefit from winter sun and heat the house 45000 litres of stormwater was retained for all domestic and some garden use, grey water was recycled for irrigation of gardens, and a carefully designed sun shade was put on the north face for passive energy.

A living space was opened to a sheltered courtyard and to the garden, the existing east veranda with wisteria provides sheltered winter sun and summer shade and the house was made accessible via ramps.

Price Place, Downer
Green House Architects
Photographer: Robbie Gibson

The conundrum of whether to keep and improve the existing house, or to demolish and start again is a reoccurring theme for an architect working in inner suburbs of Canberra. Does the embodied energy in construction materials outweigh the benefit of building a new highly efficient house? Will the new house be around long enough for this saving in running energy to be realised?

The answer is never the same and each situation has to be judged on merit.  A lot of housing built cheaply 50 odd years ago had little regard for orientation, insulation and quality.  A common wishlist is to insulate walls, double glaze windows, renovate the kitchen, open up the living area  and add a room or two. Sometimes a minor but significant change can be revolutionary and a renovation would definitely be in order. Other times the house needs extensive rearrangement and reorientation and is in such poor condition that by the time the house is stripped back ready to be renovated there is nothing left but a timber frame on some dodgy footings. If it comes to this, it may be time to start again from scratch.

If knocking down is the way to go, the next step is to do it in such a way that as much of the existing material is recycled rather than downcycled or tipped. Doing this isn’t as easy as it sounds. House dismantlers are far and few between and the ones out there are quite busy and hard to pin down.

The story of this rebuild in Downer is an interesting one. it features dismantling the existing house, reusing materials in the new one, and the owners deciding to downsize from their two existing houses and move into a new house that shared communal space but still offered independence.

The house itself was designed from the inside out with a priority given to the internal spaces. The nondescript entrance doesn’t give anything away from the street and the simple functional exterior is already beginning to be softened by the owners’ passion for gardening. It is not until the house opens up on the inside that you realise you are in something a bit out of the ordinary.

The passive solar house is super efficient to run. With no air conditioner, it stays below 26 degrees during the afternoon of a 40 degree heat wave. With 14 solar panels on the roof it produces more than two and a half times the energy it uses. Plus, more than a thousand lineal metres of timber were remilled from the existing house to make the joinery throughout. It speaks of care and consideration and provides a reminder of the old house which had been a home to the owner since the 1970s.