How to renovate and add in a better sustainable way?

Renovations and additions can improve the liveability and sustainability of your home.

Most local governments have planning policies that allow minor internal and external changes that don’t alter structure or services to be made without council approval, but it is always best to check first. Alterations to services (plumbing, drainage, gas and electrical) do require approval and inspection by the relevant authority but may not require planning or building approval.

These are the subjects that will improve you’re sustainability house:

  • Improving Thermal comfort
  • Improving Energy and Efficiency
  • Improving Water efficiency
  • Improving Indoor Air Quality
  • Improving Space and Amenity


Improve Thermal Comfort

  • Replace windows or glazing with high performance units appropriate for the climate or consider retrofitting double glazing to serviceable timber windows that you plan to keep.
  • Improve air seals as you refit sashes.
  • Use polycarbonate films with magnetic attachments to emulate double glazing during winter.
  • Relocate or reduce the size of east and west facing windows and install adjustable shading devices.
  • Remove trees or plantings that are blocking solar access to north facing glass.
  • Install heavy drapes that touch the floor and walls at each side and fix sealed pelmets on top.


Pelmets and heavy drapes

Install shading that can be adjusted for the time of year.  Pelmets and heavy drapes prevent heat loss.


Thermal mass

  • Remove carpet or other insulated coverings on slabs and replace with tiles or polished concrete finishes to expose thermal mass, in locations where exposed thermal mass is desirable.
  • Install thermal mass in rooms that have little or none and are exposed to passive heating or cooling, e.g. dark coloured, sealed water containers.

Polished concrete floors

top floor with large windows

Polished concrete floors soak up Water containers make excellent thermal mass.

the heat of sunlight.

Ventilation, air movement and draughts

  • Improve cross ventilation by:
    • Retrofitting fully openable, breeze catching windows and doors
    • Creating new openings in non-loadbearing walls and above doors
    • Moving doors to improve breeze paths
    • Designing landscaping planting, outbuildings or fences to direct breezes through the home
    • Removing planting that blocks breeze access, unless needed as a windbreak.
  • Install ceiling fans.
  • Install fans that ventilate your roof space in summer and can be sealed in winter.
  • Install doors in hallways and stairwells to control winter draughts and air movement and create heating and cooling zones.
  • Draught seal the whole building.
allow cross ventilation

Allow cross ventilation by prevailing breeze

whole house fan

Whole of house fans should be positioned centrally


  • Replace halogen down lights with low energy models, seal openings and replace insulation over them.
  • Add insulation to accessible floor, wall and roof sections.
  • If crawl spaces are adequate, simply install underfloor insulation in sheet or roll form with additional bulk insulation on top in cooler climates
  • In colder climates, or where slab heating is used, insulate slab edges, without creating termite access.
  • Consider placing a foam insulation layer up to 900mm wide under paths or paving around the home to prevent heat loss from the ground surface and maintain higher earth-coupled temperatures under the slab.
  • For cavity brick walls seek advice from insulation specialists about insulation solutions that do not breach the waterproofing integrity of the cavity.
  • Where timber framed walls are being reclad, fit new insulation under the new external cladding and create an air gap adjacent to an inward facing reflective insulation layer using spacer battens.
  • Install roof insulation when roofing is being replaced. Fit bulk insulation at ceiling level and downward facing reflective foil under roofing.


Improving energy efficiency

  • Consider installing an active solar heating system, particularly if your home has no solar access to north facing glass (see Heating and cooling).
  • Upgrade your heating and cooling system with one that:
    • Has the highest energy star rating you can afford.
    • Only heats or cools rooms that are in use.
    • Can be expanded to include future additions.
  • Install a solar or energy efficient hot water service.
  • Improve natural daylighting by removing or pruning plants that obstruct light and adding skylights or daylight tubes.
  • Replace low efficiency lighting with LED or other efficient lighting.
  • Install smart metering and control systems when rewiring
  • Choose the highest energy star rating when replacing appliances

highest energy star ratingRoof photovoltaic panels

Improving water efficiency

  • Retrofit the highest star rated toilets, showers and taps available.
  • Install flow restrictors on taps that deliver too much water, e.g. hand basins, sinks.
  • Install rainwater tanks.
  • Reduce lawn areas and convert parts of your garden to mulched, low water planting beds to save work and improve privacy and air quality.
  • Restore biodiversity by planting local native plants, which also reduce your water consumption because they are adapted to your climate’s rainfall regime.
  • Consider reusing grey water for your garden but have a soil expert explain the implications for your soil type and plants, and check which systems are approved by your council.

backyard retreat


Improving indoor air quality

  • Ensure high levels of controllable natural ventilation or fans in rooms that are difficult to ventilate.
  • Consider heat recovery ventilation systems in cooler climates (see Sealing your home).
  • Neutralise out-gassing paints and finishes already in the home with specialised sealants (see appendix The healthy home).
  • Use only low/no emission paints and E0 (zero formaldehyde emissions) or super E0 manufactured timber and joinery. Focus on the largest surface areas first: walls, ceilings and especially floor coverings.
  • Ventilate wet areas to the outside to reduce mould and mildew.
  • Check that existing exhaust fans are vented externally – not just into the roof space.
  • Ensure subfloor spaces are dry, well drained and ventilated to eliminate mould growth.
  • Use house plants to absorb VOCs (volatile organic compounds) and other toxins.
  • Avoid floor coverings and furnishings that harbour dust mites or allergens.
  • Consider a ducted vacuum system to remove toxins and allergens from the home to an externally mounted receptor.

Improving space and amenity (to reduce need for new construction)

  • Build or improve outdoor living spaces close to kitchen and indoor living areas and consider summer shade, insect proofing and winter sun.
  • Install additional, purpose built storage.
  • Consider relocating the laundry to a cupboard off a living area or circulation space to improve the connection to outdoors or access to future additions.
  • Experiment with more space-efficient furniture layouts to make room for additional functions and storage.
  • To renovate your kitchen (if the final position is fixed in your staged concept plan):
    • Choose durable, non-dating finishes.
    • Ensure the refrigerator is well ventilated and not next to the oven or other heat source.
    • Choose low or no VOC materials with E0 or better finishes.
    • Consider traffic flow and safety.
    • Choose energy and water efficient appliances
    • Include effective facilities for composting and recycling.
  • To renovate your bathroom (if it is to be retained in its current position):
    • Choose toilets, showers and taps with the highest WELS star rating.
    • Consider a two or three way design to eliminate the need for additional bathrooms (a vanity and mirror can sometimes be located in a waste space or relocated cupboard to allow simultaneous showering and tooth brushing).

renovated bathroom

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