The Greenhouse

2006 - 2007

In 2006 renovations accounted for more than 80 per cent of building activity in Australia. To demonstrate that renovators could make significant improvements to the environmental performance of their home without breaking the budget, Switch your thinking undertook sustainable development retrofits at a typical suburban home; creating the Greenhouse.

The Greenhouse, a typical 1970s double-brick home located in the south-eastern suburb of Maddington, received a number of structural and non-structural modifications designed to increase energy and water efficiency and improve thermal comfort and liveability. Renovations included:

InstallationsBenefitsCost ($)
Windows on the north facing wall of the lounge room Let in winter sun 1 300
Bi-fold doors Let in winter sun 3 828
Shade sail Shade bi-fold doors 1 500
Deciduous vines and landscaping Shade western and northern windows and walls 12000
Clay tiles Increase thermal mass and moderate temperature 1 500
Solar hot water system Energy efficient water heating 3 000
Roof insulation Moderate internal temperature 2 000
Reverse sweep fans Energy efficient cooling and heating    120
Energy efficient gas convection heater Energy efficient heating 1 200
Window tinting Keep out summer heat  
Curtains and pelmets Moderate internal temperature  2 000
Insulation paint Moderate internal temperature    615
Rendering of external walls Reduce heat absorption by the bricks 2 300
Skylight Increase natural light 1 050
Whirly bird Release heat from ceiling cavity  
Cracks covered with draught tape Moderate internal temperature      10
Energy efficient lighting Improved energy efficiency    500
Energy efficient appliances Improved energy efficiency 6 500
Rainwater tank plumbed to the toilet Improved water efficiency 1 900
Grey water system Improved water efficiency. Grey water used for garden irrigation    660
Flow restrictors Improved water efficiency    280
Low flow shower head Improved water efficiency      20
Waterwise garden and irrigation Improved water efficiency 4 290
Re-direction of down pipes to the garden Improved water efficiency    100
Worm farms Waste reduction and soil improvement    100
Composting system Waste reduction and soil improvement      95
Bokashi bucket Waste reduction and soil improvement      89

The Greenhouse was open to the public as a demonstration and education facility for one year before being occupied and monitored for another year to quantify energy, water and waste savings as well as thermal performance.

The results of the occupation phase showed that relatively small investments could yield significant improvements in resource efficiency without sacrificing occupant comfort.

Outcomes

The Greenhouse welcomed 2 500 visitors who learned about sustainable renovations.

  • The Greenhouse saved over five tonnes of greenhouse gas emissions compared to the control house during the occupation phase.
  • The Greenhouse saved $1 250 in utility bills over the one year occupation phase. 
  • Anecdotal evidence from local real estate agents that visited the Greenhouse suggested that the retrofits undertaken had increased the property’s value by $100 000, providing a huge return on investment and demonstrating an additional incentive for home owners to incorporate sustainability into any future renovations.

For more information
Download the special Green House Lift-Off
Download the full Phase 2 (Home Occupancy) Report