Rating tool helps to clear the air

The Green Building Council of Australia (GBCA) has released the Green Star — Multi Unit Residential v1 environmental-rating tool.

According to the Chief Executive of the GBCA Romilly Madew, the Green Star tool will enable building owners and developers to minimise the environmental impacts of their developments and receive recognition for more environmentally sustainable design.

The announcement comes in the wake of the Council of Australian Governments’ move towards increasing the energy-efficiency requirements of the Australian Building Code and moving to a minimum six star energy-efficiency rating for all new Australian homes.

“Residential buildings in Australia are responsible for 13% of the nation’s greenhouse gas emissions, and Australia’s level of emissions per home is one of the highest in the world. The new Green Star — Multi Unit Residential v1 rating tool will help to reduce our emissions and support new stringent energy-efficiency requirements in the Building Code of Australia,” Madew said.

The tool is applicable to new multi-unit residential facilities and extensions to, and major refurbishments of, existing multi-unit residential facilities of two units or more, provided they meet Green Star eligibility criteria.

The tool has undergone a rigorous assessment period, after a pilot phase, and refinements to the calculators and credits have already received positive feedback from industry, according to Madew.

The new rating tool has many credits in common with the other Green Star tools but also includes a number of credits specific to the multi-unit residential sector. These sector-specific credits address a number of issues that are particular to multi-unit residential buildings such as energy and water efficiency of appliances, control of lights and air conditioning in unoccupied spaces, universal design and the provision of communal facilities.

The rating tool also includes a customised energy calculator. While the Green Star — Office suite of rating tools incorporates energy modelling consistent with the NABERS Energy tool, an equivalent modelling protocol did not exist for the multi-unit residential sector.

The Energy ‘Conditional Requirement’ in the rating tool is to be a uniform 10% above the minimum thermal performance requirements established by regulation in each state. This approach acknowledges the current regulated minimums across the country. It also allows state jurisdictions to amend their regulations and adjust their benchmarks, with the Green Star benchmark changing accordingly. This approach uses existing documentation and energy modelling in all jurisdictions other than the Northern Territory, where there are no current minimum thermal-performance requirements.

“The tool will also provide state and local governments with a framework for planning guidelines and development incentives,” Madew said.

“While the Green Building Council of Australia does not advocate Green Star as a mandatory regulation tool, it does encourage Green Star as a support mechanism for incentives, and the GBCA is currently in discussion with a number of authorities on how to apply the Green Star — Multi Unit Residential v1 rating tool to the allocation of bonus floor areas, fast assessment of development applications and cash incentives for green developments.

“We are confident that the Green Star — Multi Unit Residential v1 tool will deliver a single third-party certification that the residential market can understand and trust, and that property developers can use to demonstrate their development’s green credentials."

The rating tool is available for download from the GBCA website, as well as for independent third-party accredited assessment.