Having grown up in the northern beaches and spent 15 years in the original house, obliteration of the modest suburban brick home was not desirable to the clients. But neither was the home’s collection of chopped up rooms which were dysfunctional, dark and cold. We approached the project with the ideas of modernism – functional yet beautiful, modest yet spacious. These principles were translated into relevant contemporary solutions – incorporating the adjacent bushland reserve, addressing environmental sustainability through passive solar design, and meeting the client’s goal to be as green as possible.
Budget was also an important consideration. Through careful design choices, intelligent space planning and a rigorous process the build cost about 30% less than a typical architect-designed home. Integrating passive solar design also means the house is affordable to run year-round.
Prior to engaging Marra + Yeh the clients had discussed plans for a renovation with a draftsman, but were left feeling the potential of their home would not be realised. The house sat on a sloping block and faced an adjoining reserve with mature gum trees. However, neither the slope nor the reserve outlook had been incorporated. Passive solar design was desired by the clients to improve comfort and could only be achieved by reorienting the house and turning the slope into an opportunity.
The primary consideration was to make a small house so as to reduce resource use and site disturbance. At 180 sqm for a family of five it is roughly 30% smaller than the average Australian house. Sustainable materials like timber from certified and local sources were chosen for its ease of construction and aesthetic appearance. The building is predominantly lightweight but thermal mass was incorporated both in the slab and the south wall. Cross ventilation is achieved for all the living areas with openings that can be left open at night to flush the building. The roof form was driven specifically by the need to accommodate solar panels that would have sufficient north exposure with minimal overshadowing. The roof form also achieves passive solar design by incorporating north-facing windows.
The outdoor areas function as specific microclimates, the new courtyard being warm and protected from winds in winter while the south deck is cool and shaded in summer.
Passive solar design principles have resulted in higher energy efficiency. In particular, electricity consumption has been reduced by 30% throughout the year despite a 35% increase to the area of the house. The house has been put to the test during 45-degree days and the spaces remain comfortable without air conditioning.
This solar passive house includes plenty of storage, big volumes as well as small ones, and spaces that flow from one area to the next and then outwards to the treetops and the sky. The result is a home of small footprint but generous proportions, high environmental performance and where every room has an outlook to the tree canopy.