Retrofit at Mount Ommaney

The House
The original two storey brick veneer federation style house was constructed in 1987, and owned by John and Rosemarie Cole. He is an executive in the EPA and has a personal as well as a professional interest in sustainable housing. The house’s original floorplan did not address the rear of the property. The verandahs that were built as part of the original house, provide shading to the internal areas, however they did not provide a sufficient area for the family to gather in. The rear of the house was closed off and was subject to large heat loads from the western sun. Internally the room at the rear of the house required air-conditioning to be used during summer, due to this heat load.. The pool is located to the north eastern side of the house and the tennis court to the rear of the site, each area was independent and unconnected, thus reducing the overall amenity of the site and the livability of the different areas.

The Solution
The solution was to integrate the house and site and provide connectivity with the living areas and the landscape. The existing door and window were removed and replaced with a large bi-fold opening. This transformed the internal flow of the house, leading the residents out to the backyard and connecting with the swimming pool area. It also allowed the swimming pool to act as a passive cooling device, encouraging the cooler air into the back rooms of the house. Screening devices were also installed around the pool areas to provide privacy from neighbors.

A large patio area was constructed between the house and the tennis court. The roof of this space was lifted above the height of the existing roof, to encourage air flow through the area. The roof structure was softened with layers of battens and a mix of colorbond and polycarbonate roofing, providing layers of light and shade.

This allows airflow and natural light, while providing a cool shaded area to the rear of the house. The location of the battens and polycarbonate, have been designed to allow lower winter sun to penetrate into the space, while blocking the higher summer sun. The polycarbonate allows natural diffuse light to penetrate the South Western corner of the patio, the area under this has been given over to a garden bed. Stainless Steel Wires have been provided to create a trellis for vegetation to grow over, providing a natural air filter. The garden is drip fed from an irrigation system supplied by the water tanks, reducing reliance on Council water mains.

The structure of the patio consists of recycled hardwood timber and laminated ‘Hyne’ beams. The timber feature battens which have been used are a manufactured product called ‘Modwood’, made out of sawdust and recycled milk bottles. The battens have an integral color through out them, this means they look like natural timber, however they do not have to be painted and will not warp and splinter over time, thus giving the feel and effect of timber but minimising the long term maintenance and the reliance on our limited natural timber resources.

During the alternations 3 tanks, which can hold a total of 20,000L of water, were also installed. These tanks will top up the pool, water the tennis court and irrigate the garden.. The lights installed to the new extension are a mix of low energy compact fluorescents and traditional halogen.

The Result
The original house and external landscaping were not united and acted as three separate unconnected areas. The idea was to link these areas into a harmonious whole, creating an openness and flow throughout the house. The patio provides a strong central anchor point, intertwining the internal living areas of the house with the external ‘play areas’, the tennis court and the swimming pool. It provides an outdoor living space, that is cooling in summer while still allowing the winter sun and natural light to penetrate the house.

The al fresco extension is a great example in sustainable design and the client has given permission for the project to be used as a case study for the EPA’s Climate Smart Living program segments of which will be featured in the media in up-coming months.

Stage 2 will involve looking at the internal plumbing and fittings to save more water. Then assessing the light fittings to see where energy savings can be made.

Stage 3 will modify the passive elements of the home to flood extra natural light in. Then include permaculture and edible gardens outside, all fed by excess recycled water.

Clients Comments:-
“It looks great, we are making a difference to the environment, and the workmanship is excellent. The water tanks help us to be self-sufficient with water and we feel the future is protected in a small way. It is the cleanest building site I have ever seen. The guys are nice people, always on time, hard working and courteous. We signed the contract and the work started the following week, we can’t wait for it to be finished. It looks great and the passive cooling effects achieved by the design are easily felt in the air flows through the house, eliminating the need for air-conditioning in the main living areas”.

Builder: Sustainable Landscaping
Design: Sustainable Design
Architect : Sascha Christensen