Around half of the energy used in an average Canberra home is for heating and cooling. By effectively insulating and draught-proofing your home you can reduce the amount of warmth escaping in winter and the amount of heat entering in summer. This will make your home more comfortable, reduce your heating and cooling bills and help to reduce greenhouse gas emissions.
- Good insulation in your roof, walls and floor will keep your home cooler in summer and warmer in winter, and could save you up to $100 every year. Start with the roof first as you can lose up to 40% of the heat in your home through the roof; 20% through walls and up to 15% through the floor.
- The higher the R-value (Thermal Resistance) of insulation the more it slows heat flow and the better it insulates. R5 is recommended for the ceiling; R2 in the walls and under suspended floors or around slab edges.
- There are two types of insulation products (bulk and reflective) that work in different ways. Seek advice from an insulation retailer to help you choose the right type of insulation product for your situation.
- When building or renovating, install high R-value wall insulation.
- Double glazing can reduce heat losses through windows by 40 to 60 per cent.
Tips for installation
- Ensure that anyone who installs loose-fill or batt-type insulation does not compromise the fire safety of recessed lights. See this Insulation Warning and Foil Insulation information provided by the ACT Planning and Land Authority.
- Have your wiring inspected by a licensed electrician to ensure it can be safely covered by insulation and ask about the mandatory clearances around light fittings and transformers.
- Make sure your insulation installer is trained to meet relevant Australian Standards and that they certify your installation meets relevant Australian Standards.
- Gaps in insulation can significantly reduce the effectiveness of insulation. However safety clearances must be left around exhaust fans, hot flues, recessed light fittings, transformers, etc.
- Batt type insulation, when expanded to its natural thickness, should fit snugly between ceiling joists and be kept clear of recessed light fittings.
- Reflective foil requires a still air gap of at least 25mm between it and the associated surface.
- Loose-fill or blow-in insulation should be sprayed with a sealant to reduce disturbance from breezes in the ceiling cavity. It should also be kept clear of recessed light fittings and exhaust fans.
Make good use of window treatments
Lined curtains and properly fitted blinds with box pelmets can seal in the warmth in winter and keep the heat out in summer. In winter, open them during the day and close them at night to cut your heating bill by up to 10%. In summer, close curtains, blinds, windows and doors during the day and open them in the evening when temperatures fall to let evening breezes cool your home naturally.
- Maximise heat control with close-fitting lined curtains and blinds.
- Ensure your curtains go all the way to the floor and wrap to the wall on either side of your window.
- Line your curtains with ‘blockout’ backing to prevent radiant loss (and reduce summer gain).
- Use tightly woven materials, trapping air in as many layers as possible.
- Install box pelmets to reduce the air circulation around your windows.
- When selecting blinds, consider those with built-in air cavities and ensure they fit snugly to the window frame.
Seal cracks and gaps
Cracks and gaps in houses can account for 10% to 15% of heat loss.
- The smoke from an incense stick held near your doors and windows on a windy night can quickly show up any gaps that need filling.
- Installing draught excluders under doors, foam strips around windows and sealing around skirting boards and architraves are often the most cost effective ways to improve how warm your home feels.
- Fit draught seals to the base of doors and weather strips to door jambs.
- Seal up any unnecessary permanent vents (often found in the walls and ceilings of old homes) unless you are using unflued gas heaters.
- Fit covers on exhaust fans which vent straight into the roof. These open when the fan is in use but stop draughts at other times.
- Your Home Technical Manual Insulation Installation.