Officer Woods Architects is the winner of the Multi Density Residential award for its development of 58 Stevens Street.

The clients were landscape contractors with a sincere environmental consciousness who wanted a development that could be divided to yield more than four dwellings should the local density code change in the future. The brief also called for sustainable building practices, materials and finishes, minimal ongoing maintenance or costs and a long life cycle.

The judges said: "Making an intelligent use rammed recycled rubble as mass, the onsite recycling and adaptive reuse of materials represents genuine innovation. It’s an effort well beyond the norm.

"The use of eTool assessment is to be commended; the solar orientation is excellent; and the project cost is impressive. "

The dwellings have been designed to facilitate multiple modes of occupation over time with only minor modifications required for reconfiguration for a home office, granny flat or additional bedrooms.

Recycling was a key aspect of the construction process as a model was piloted by Earthcare Recycling with waste sorting and separation conducted on site in mini bins which allowed 80 per cent of the building waste to be recycled and diverted from landfill.

Another innovation used by the architects was the low embodied energy mass walls which are made of rammed recycled building rubble (most of it from the demolished bungalow previously on the site) and are located on the southern boundaries to provide thermal storage as well as retaining, acoustic and fire separation.

INITIATIVES

  • Mandatory energy efficiency requirements of the local council, state residential design codes and BCA were met and surpassed.
  • Each house has a 2Kw PV array for solar power generation and low energy fixtures and lighting. Rainwater is harvested from all roofs and collected in four 3000l tanks which are plumbed to all WCs and washing machines for reuse. Each house is double plumbed for grey water recycling. All fittings are 4 star or greater WELS rated water efficient. Water-wise gardens have been planted with extensive endemic coastal native species.
  • In all standard configurations, garages have been prepared with finished slabs, linings and pre-wiring for easy conversion to home offices or commercial shopfronts, encouraging blended live work arrangements. A central nib wall has been serviced with gas, water, power and plumbing, so that each house may be easily and affordably divided in the future to accommodate an additional bedroom or completely separate self contained dwelling with its own entry.
  • Eco blend concrete for footings and slabs, Low E glazing, local timber veneer on E zero particleboard and natural stone for cabinetwork, natural Albany wool wall and ceiling insulation, Aircell roof insulation, Livos timber sealer, Agar first base concrete sealer, 4 star or greater WELS rated fittings and fixtures, LED lighting throughout.
  • The houses are built on reclaimed rather than clean fill.
  • An eco-blend concrete was used for all ground floor slabs. Additionally, jarrah floorboards from the demolished original cottage are reused in the upper floor bedrooms and studies.
  • All existing mature trees and a large portion of limestone rubble on site have been retained and/or relocated.
  • Engineers at the Perth-based eTool carried out a life cycle assessment (LCA). eTool found that the development is close to carbon neutral, representing a reduction of about nine tonnes of CO2e per annum per dwelling.