2006 - 2009 Multi-dwelling outcomes

BASIX is the NSW Government's residential sustainability program for all new housing in the State. Under BASIX housing developers are obliged to commit to water and energy-efficient building designs before development approval is granted.

This document summarises the 2006-09 BASIX Multi-Dwelling Outcomes report and presents the sustainability commitments made in NSW for all new residential developments of more than one dwelling between 1 July 2006 and 30 June 2009, including units, townhouse rows and subdivisions.

The impact of BASIX is most evident in the increased use of alternative water sources, particularly water tanks, in most new dwellings, the greatly decreased use of inefficient
electric hot water systems in new homes and high NatHERS Star Ratings reducing the energy required to heat or cool the home.

46,000 new multi-dwelling homes

improved by BASIX

61% of new multi-dwellings use

alternative water

130,000 bottles of water saved

every year in each multi-dwelling

99.8% use gas, solar or heat pump

hot water instead of electric

203,000 tonnes of greenhouse gas

already saved

5.25 average NatHERS star rating

for BASIX multi-dwelling


Since October 2005, all new residential developments of more than one dwelling have had to meet mandatory water and greenhouse gas emission reduction (energy) targets of up to 40 per cent from an average pre-BASIX NSW home.†

BASIX has improved the sustainability of 4,753 new multi-dwelling developments in NSW, comprising over 46,000 individual homes.

Unique sustainability tool for large developments

BASIX has designed separate tools for single and multi-dwelling developers because energy and water consumption patterns vary significantly between these types of developments. The BASIX Multi-Dwelling Tool includes technologies specifically suited to larger residential developments, especially for unit blocks with common areas such as car parks, lifts and shared gardens which can require significant amounts of water and energy.

Over 60% of all BASIX multi-dwelling homes were units in residential flats.

The importance of a specific tool to deal with units is illustrated in the large proportion of unit homes certified by BASIX, reflecting trends in NSW housing development towards denser dwelling types (see following graph).

outcomes multi_1Multi-dwelling homes certified by BASIX during the reporting period 

NSW Green State targets

The NSW 2010 State Plan committed the State to 60 per cent emission reductions by 2050, and saving 145 billion litres of water a year by 2015. New BASIX multi-dwellings are predicted to have already saved around 6.5 billion litres of water and up to 203,000 tonnes of greenhouse gases.

Savings from multi-dwellings are equivalent to the water used in over 2,500 Olympic swimming pools and the annual emissions of over 9,000 cars for five years

The average BASIX multi-dwelling home is predicted to use 78,000 litres less potable water and emit 2 fewer tonnes of greenhouse gases per year than an average pre-BASIX home. This is roughly equivalent to every new multi-dwelling saving 130,000 bottles of water a year and around 50 per cent of an average car’s annual emissions.

BASIX reduces water consumption

Majority of multi-dwellings connected to an alternative water supply

outcomes multi_2Alternative water use in BASIX multi-dwelling homes 

94 per cent of multi-dwellings with alternative water used rainwater tanks - before BASIX was introduced, only around 12 per cent of all NSW dwellings had rainwater tanks.

61% of multi-dwellings now use a tank or recycled water supply rather than mains water for part or all of their toilet, laundry and irrigation needs

Many unit blocks may not connect alternative water directly to individual dwellings, but instead reduce water consumption by connecting tanks or greywater systems to irrigate shared gardens. For units in residential flat buildings, 73 per cent of shared common gardens use an alternative water supply for irrigation.

Water-efficient fixtures and appliances in all homes

Australia’s Water Efficiency Labelling Scheme (WELS) requires clothes washers, dishwashers, taps, toilets and showerheads to be registered and rated according to the amount of water they use. The minimum WELS rating for toilets and taps is now three stars, but around 50 per cent of all new multi-dwelling homes commit beyond these standards to taps rated four stars or higher, and over 40 per cent committed to toilets rated four stars or higher.

BASIX homes reduce water demand with taps, toilets and appliances beyond minimum efficiency standards.

outcomes multi_3BASIX multi-dwellings with taps and toilets rated 4 stars or higher. This graph shows that growth in high performance taps and toilets has steadied, indicating further stringencies may need to be introduced to improve fixture efficiencies further.  

For units in residential flat buildings, committing to water-efficient dishwashers and clothes washers can contribute to meeting BASIX targets. Minimum WELS performance standards on installed appliances have yet to become compulsory in Australia, but 31 per cent of clothes washers and 38 per cent of dishwashers installed to BASIX units had a rating of four stars or higher. The lowest available product for both has a rating of one star.

BASIX reduces greenhouse emissions

Phasing out emission intensive electric hot water systems.

The following graph shows how new BASIX multi-dwellings are phasing out high emission electric storage and instantaneous hot water systems. These systems were used in 67 per cent of existing pre-BASIX homes in NSW, and now feature in only 0.2 per cent of new multi-dwelling homes.

outcomes multi_4Hot water systems in BASIX multi-dwellings 

18% of all BASIX multi-dwelling homes now use solar energy for hot water compared to only 3% of preBASIX homes

Reducing the need for heating and cooling through good building design

BASIX calculates how much energy is required for heating and cooling a dwelling based on the design and construction materials of a new home, such as insulated ceilings and walls or performance glass installed to better retain and deflect heat.

Improving these features can contribute significantly to meeting BASIX energy targets as over 13 per cent of average emissions in pre-BASIX homes were attributable to heating and cooling the home.

Securing the sustainability of shared facilities and common areas

Pre-BASIX data indicated that up to 50 per cent of per capita emissions for a high-rise unit dweller were attributable to common area energy use. The primary contributors were continuous car park ventilation and round-the-clock incandescent or halogen lighting.

The following graph indicates some of the key improvements new developments are making to common areas to improve BASIX scores.

outcomes multi_5Common area efficiency improvements 

Committing units to energy efficient appliances

71% of multi-dwellings commit to an energy rated dishwasher 63%

commit to a rated clothes

51% commit to a rated clothes washer 39% commit to a rated refrigerator