Design Brief
The clients, who are both medical specialists, wanted their house to be the opposite of the artificial environment in which they work.
They desired a home with a relaxed non-clinical ambience that opened up to the outside and brought the western view in. This meant that external blinds to control the westerly afternoon sun needed to be avoided to keep the view open.
The house had to be thermally comfortable without air-conditioning, but with the indoor air being naturally ventilated and non-toxic.
The design had to allow for enough light during the daytime without the need for artificial lighting.
Wheel chair access to the main level of the house from a rear carport was also required.
Overall the house needed to be energy and water efficient and require little maintenance.
Design Solution
The main floor of the house, comprising the living areas of the house and guest bedroom, is placed level with a rear carport to allow easy wheelchair access and a level backyard on the otherwise steep site.
The house maintains a single storey aspect to the rear (east) with a flat roof to maintain the water views of the rear neighbours.
The living areas open up to the view onto a large sweeping timber boardwalk.
The bedrooms are below this floor and form the podium for the main floor and boardwalk above. The bedrooms open to the view onto individual partially enclosed balconies.
A sheltered undercroft hides the rainwater tanks, solar hot water heat exchanger and clothes lines.
To avoid sun control blinds on the west facing viewing windows and doors, the western facade of the main floor steps back in such a way as to block the afternoon sun, making this the only house in the street not requiring blinds.
During winter, clerestory windows reach for north & east solar access above the northern neighbour.
All habitable rooms have external openings on at least two sides to facilitate cross ventilation within each room, and multiple windows mean the house is flooded with daylight, making artificial lighting during the day redundant.
Material Considerations
The passive solar design, heatbanks, insulation, double uPVC glazing and stack ventilation maintains the thermal comfort of the house with the internal temperature mostly between 20 and 24 degrees without artificial heating or air conditioning.
Stack ventilation is integrated into the design, whereby cool air is naturally drawn into the house from the shaded under-croft of the house through motorised floor vents and exhausted through motorised clerestory openings.
This stack ventilation operates independently from the doors and windows and operates even when the house is locked down for the day, ensuring the house is filled with fresh air when the clients return after work.
To further enhance the indoor air quality, no toxic materials or finishes are used. The non porous porcelain floors throughout the house and hardwood boardwalks require no finish.
Gas boosted solar hot water provides hydronic floor heating and domestic hot water. LED, CFL and energy efficient halogen lighting is used together with energy efficient appliances and fittings to minimise electricity use.
The external face brick walls, untreated hardwood boardwalks, stainless steel balustrades and non porous porcelain floors minimise maintenance.
Consultants & Contractors
Building Designer - Ardea Oosthuizen, Ecobuild Design www.ecobuilddesign.com.au
Photographer - Paramount Studios
Civil Engineer - Northrop
Electrical consultant - Special Lights
Hydraulic consultant - Smart Heat
Builder - Ecobuild
This article was written with the assistance of Building Designers Australia.
