BVN’s Project Zero is a model for the delivery of minimal energy use in residential development to the broader market.

The scheme is underpinned by a commitment to re-use. An existing hardwood framed and clad dwelling was relocated and adjusted for the new circumstance, and the additive parts were constructed from recycled materials where possible.

Such an ambitious sustainability agenda required a huge commitment to research to ensure that the original intent could follow through into the construction. Finding the most suitable materials, systems and suppliers throughout construction was a task that BVN, their client and the environmental engineer engaged with in great detail.

A timber structure that is only screened above two metres acts as a formal device to identify changes in level and to unify a number of disparate elements. Providing a degree of spatial enclosure and privacy to a flat landscaped area this structure also acts as a major organising device reinforcing the overall plan.

A glass screened swimming pool takes up one corner of the landscaped space, beneath which is what is considered to be probably the Australia's largest domestic rain water tank that will be used for flushing and gardening purposes.

The design of the house minimises the need to artificially heat or cool the building. Folding screen doors completely open the house to the garden and this together with high level windows enables breezes to be drawn through the living spaces. These windows also project southern natural light down into the living space. The extensive use of shade structures and screens provide privacy and also act as trellises for climbing plants to provide seasonal shading. The screens allow winter sun into the living space to heat the thermal mass of the brick floor, making the house comfortable through Brisbane's mild winter.

The smart building management system coupled with the PV cells and battery bank means the house had a net energy surplus of 16 per cent in the first year. A 250KL subfloor rain water tank easily accommodates water needs for landscaping and non-potable uses. The net water consumption has been less than 25L per person per day.

KEY INITIATIVES

• Underpinning the approach was the desire to re-use existing building stock (many examples of which are built of now rare eucalypt timber) located on an underutilised site
• The existing post-war house was relocated to the rear of the site to improve solar orientation and to form part of a composition of new and old buildings and spaces surrounding a central garden
• A new western living wing includes on-site water recycling, smart energy systems and incorporates passive design strategies like thermal mass and considered shading and ventilation systems to minimise heating / cooling requirements
• Reclaimed and recycled building materials were used extensively in construction
• The landscaping includes a productive garden, compost/worm farm and extensive native planting