6/13/20161 The Link Between Sustainability, Affordability and Residential Design Michael Wohlstadt Michael Wohlstadt One Aspect

6/13/20162 Key Questions Is there the potential to deliver better environmental outcomes through dwelling siting and design for householders and the community?

6/13/20163 ► If yes: -is the difference measurable and worthwhile? -does the development system have a role in ensuring delivery?; -are the mechanisms a planning or building question?; -do the current 2008 South Australian development legislation reforms (Residential Code) capture the opportunity?; -is approach taken in the Code consistent with the South Australian Government’s Strategic Plan?; -what changes could be made to the Draft Residential Development Code?

6/13/20164 ► Gawler Research by Dr Helen Bennetts Modelling of a popular design of project home against a range of orientation positions and shading options on: heating and cooling energy; heating and cooling energy; associated greenhouse gas emissions; and associated greenhouse gas emissions; and the associated economic cost. the associated economic cost. The house design is a popular three bedroom project home with conventional construction: brick veneer, concrete slab- on-ground and concrete tile roof. There are windows in all orientations, although most are to the side elevation with the Living, Meals and Family room. The main living zone (Living, Meals and Family room) has windows in two orientations 75% of the window area to the side elevation and 25% to the rear.

6/13/20165 Assessment of the heating and cooling load and the star rating from the AccuRate simulations with four different options: 1no shading; 1no shading; 2eaves; 2eaves; 33 metre verandahs; and 33 metre verandahs; and 43 metre adjustable shading. 43 metre adjustable shading. Each of these options is simulated with 16 variations (the original design and the mirrored design in 8 orientations).

6/13/20166 Figure 1: Orientation and design variations modelled in the simulations

6/13/20167 Beyond what is already known, ie that some orientations are better than others, the Gawler Research show that: ► different shading solutions are required for different orientations; ► the energy demand for cooling for some orientations can be twice others; ► methods of shading that are responsive to seasonal change are the best; ► good orientation and shading can reduce greenhouse gas emissions by 22%; and ► good orientation and shading can reduce energy costs by 24%.

6/13/20168 The order of difference over the business as usual case has the potential to be significant: ► Gawler’s population will grow by 100% over the next years; ► 6,000 new dwellings; ► Savings are equivalent to 2500 tonnes per annum of greenhouse gas; ► Equivalent to 30,000 trees over 10 years to absorb equivalent amount of CO2; ► Equivalent to around 300 dwellings or 5% of the total of new dwelling stock would be effectively carbon neutral. ► Outcome compares favourably with Productivity Commission Inquiry Report, by 2014 householders will have overlooked cost-effective actions compared to a business as usual model that could reduce energy consumption and greenhouse gas emissions by at least 13%. ► For the proposed new urban area in the Gawler LGA it is a saving of $1.6M per annum or $16.8M over 10 years. The Gawler outcome can be readily transferred to Adelaide’s annual dwelling demand which was 7,00 dwellings over the 4 years to 2004/05 and is projected to grow to 9,000 dwellings based on the State population target, ie 4,200 CO2 tonnes pa, the equivalent of 525 carbon neutral dwellings.

6/13/20169 Window OrientationRecommendation NorthMinimum requirement:  Shading of North windows Design Technique (One Way):  450mm wide eave Desirable:  Location of major living areas with adjustable shading  Adjustable shading for North-East and North-West West, EastMinimum requirement:  Restricted window area  Fixed shading designed to limit solar gains in summer Design Technique (One Way):  450mm wide eave  Adjustable shading Desirable:  No west facing living areas  Fixed shading of at least 1.5m width for all western windows, or additional adjustable outside window vertical screening SouthMinimum requirement:  Fixed or adjustable shading to limit solar gains in summer Design Technique (One Way):  450mm wide eaves Desirable:  Location of major living areas with adjustable shading Advisory: Adjustable shading can take a number of forms: -horizontal shading such as pergola with a deciduous vine, or shade-cloth or similar that can be removed when not required. This form of shading can reduce air temperature beneath the shading and the ground beneath which also reduces heat gains reflected from ground; or -vertically, in the form of blinds or shutters.

6/13/ Comparison of REES with potential from Gawler Research Predicted Greenhouse Reduction per annum CO 2 tonnes improvement over busine s s a s u s u a l Equivalent Number of Carbon Neutral Dwellings pa (a) Economic Benefit per Household pa (b) REES ,00013%20,000 – 40,000$35-$45 Gawler Research Total Metropolitan Dwellings 2008 (approx. 7,000) %375$264 Gawler Research Total Metropolitan Dwellings 2050 (approx. 10,000) %525$264 (a) based on average of 8 tonnes per annum (b) 2008 $’s.

6/13/201611

6/13/ The analysis shows that although site orientation and shading have the potential to: -reduce greenhouse gas emissions by 22% -reduce energy costs by 24% - make a significant contribution to the State’s Strategic Plan and Greenhouse Gas targets; The Draft Residential Code makes no contribution to environmental management. There is scope and a sound environmental basis to amend the Draft Code in the following areas: optimum orientation of private open space and major indoor living areas; and optimum orientation of private open space and major indoor living areas; and shading of major windows. shading of major windows.

6/13/ Key Questions Is there the potential to deliver better environmental outcomes through dwelling siting and design for householders and the community? If yes: -is the difference measurable and worthwhile? -does the development system have a role in ensuring delivery?; -are the mechanisms a planning or building question?; -do the current 2008 South Australian development legislation reforms (Residential Code) capture the opportunity?; -is approach taken in the Code consistent with the South Australian Government’s Strategic Plan?; -what changes could be made to the Draft Residential Development Code?