8.11 Yarra Junction, Victoria

This case study shows how a well designed suburban home can cost effectively minimise its environmental impact whilst simultaneously improving comfort and lifestyle for its occupants.

The innovative wall construction system used yields high level insulation whilst providing thermal mass and reducing noise transmission.

The house also eliminates heating, cooling, water and sewage disposal costs.

This single storey house has been designed to allow for maximum winter sun whilst totally excluding summer sun. It is split into two sections: the main section has three bedrooms and a study while the second section is a self-contained unit with a separate living area. The brief called for the house to be very comfortable and take advantage of the magnificent views. The house was designed with a high emphasis on winter warmth with low running costs as the house is in an area that can get quite cold as it is surrounded by Yarra Valley mountains.

The site is in an urban residential area in the Yarra Valley, Victoria. It is surrounded by mountains that often have snow on them in the winter. It has a gentle slope down to the East. The northern aspect of the block is open with no overshadowing from trees or other houses.

The climate is temperate to cool temperate. The prevailing winds coming from the Southwest in winter and temperatures in the area range from –5º in winter to 40º in summer.

DESIGN SOLUTIONS

The land has northerly aspect to the long side of the block. This allowed the design of the living, lounge, dining and kitchen to have northerly aspect. This amount of solar access enabled the house to be designed so that it did not require any auxiliary heating devices. Great northerly aspect and good passive solar design were combined to maximise winter sun penetration.

High levels of insulated thermal mass in the wall and floor construction absorb this free energy from the sun during the day and re-release it at night. This maintains winter indoor temperatures above 17º with no auxiliary heating. The designer was asked to incorporate two separate living quarters under the one roofline. The only part of the house to be shared was the laundry.

The unit was not to look any different to the rest of the house and was to take advantage of the northerly aspect and views just like the main section of the house and required a separate entry. These client requirements were successfully achieved by locating the unit at the front of the block.

Specially designed shade battens on all windows exclude all summer sun to protect the house from overheating in summer. Well designed cross ventilation paths allow cool breezes to draw heat from thermal mass when night time temperatures are lower, maintaining summer daytime temperatures below 24º. The western side of the house was also designed with minimal windows.