Improving efficiency and comfort on a tight budget

Most Victorian homes are uncomfortable to live in unless heated or cooled for most of the year. Older technologies used for heating water, lighting and pool pumps can be really inefficient, meaning that households pay far more than they need to run these appliances.  

There are ways to reduce the amount of energy being used, which leads to lower electricity and gas bills, makes the home more comfortable and can help to manage some medical conditions.

Here are some simple and fast ways to help reduce your energy bills. Check each rating on your Scorecard certificate to understand which changes will have the biggest impact for you. 


  • Keep the thermostat at 20oC or below for your winter heating. Every degree higher can increase heating costs by around 10%.
  • Close off rooms that are not in use.
  • Only run the heater when required. Turn it off overnight and when you leave the house.
  • Seal gaps and cracks around doors and windows or use draught excluders (door snakes).
  • Use curtains or blinds on windows. For best results use drapes (heavy curtains that reach the floor and either side of the window to create an air barrier) along with pelmets. Keep them closed from late afternoon to keep heat inside. Use a wheat bag or other type of heat pack to heat yourself. Ensure you follow the instructions to stay safe.
  • Try putting on a heavy jumper and use blankets while watching TV at night.

Hot water systems

  • Take shorter showers (4 minutes is good).
  • Install a low flow shower head.
  • Leave mixer taps in the cold position after use.
  • Fix any dripping taps, especially hot water taps.
  • Where practical, run your washing machine on a cold wash.


  • Switch the lights off when the room is not in use.
  • Use natural lighting wherever possible.
  • Install more efficient LED (light emitting diodes) or CFL (compact fluorescent light) lamps when new bulbs are needed.

Pools and spas

  • Always use a pool cover when the pool is not in use.
  • Try setting the water heating temperature 1-2oC lower.
  • Consider reducing the pump running time, especially over winter if it does not affect the water quality.


  • On hot days, close the curtains during the day to keep the heat out.
  • Use external shades on north, east and west facing windows to keep the heat out.
  • Use ceiling and pedestal fans before turning on the air conditioning.
  • If it is comfortable for you, then set the thermostat around 24-26oC. Every degree lower can increase running costs by around 10%.
  • Ensure that windows and doors are closed when the air conditioner is on. Note that evaporative coolers work differently to air conditioners and require that air is able to leave the home, eg through open doors or windows.
  • Only cool the rooms that are being used.
  • If its cooler outside, consider opening windows at night or early in the morning to let the cooler air in before a hot day.
  • Try not to use a clothes dryer, particularly in summer. Hanging washing outside will prevent the house from heating up from the clothes dryer.
  • Avoid using the oven on hot days. Try a cold meal or cooking outside on the barbecue.

If you have solar electricity

  • Use your appliances during the day if possible so they use the energy directly from the solar system.
  • Check your solar system is working well by noting the production regularly, for example, monthly. Address any issues as soon as possible.

Handling heatwaves

A home with a low Scorecard hot weather rating is relatively hard to keep cool without using cooling appliances. A high-rated home stays cool when the power goes out. When the power is on, the home uses less electricity, reducing energy bills and producing less strain on the energy system on hot days.  

Why you need to keep cool 

Exposure to excessive heat can cause significant harm, particularly for some higher risk groups. If your home ever gets above 26 degrees inside, you should consider taking action, as there is evidence this can impact on your health. 

Top three ways to heat-proof your home

1.  Protect your windows from heat

Shade north facing windows

Image: Sustainability Victoria

Windows – the glass and the frames – let heat from outside into your home. Shutters or external blinds on windows hit by the sun can make your home more comfortable in hot weather, especially if they keep the sun off the windows all day. Deciduous plants can block summer sunlight on a window and let it through in winter. Low-cost temporary shading, like matchstick blinds hung outside the window, can also work well.  

Curtains and other internal window coverings don’t work as well as external blinds, but do help keep heat out. Your aim is to create a still air space between the covering and the window, trapping the heat. Heavy, lined, floor-length curtains with pelmets, honeycomb blinds or Roman blinds work best, but any thick curtains will help.

2.  Improve your ceiling insulation

It is relatively easy and cheap to get insulation installed if your ceiling space is accessible. This job is best done by a professional installer. Use insulation with a minimum value of R3.5. Cover as much of the ceiling as possible – even a small uninsulated area will let hot air in. If your ceiling is already insulated, you can put more insulation on top.

3.  Seal gaps and cracks

Gaps and cracks let heat into your home from outside. They are often hard to find, but simple and cheap to fix. Air can get in around windows and doors and under skirting boards. Exhaust fans let in a lot of hot air, and in older homes, wall or ceiling vents can be the culprit. Your Scorecard assessor will help you find hidden gaps and suggest the most cost-effective ways to seal them.

If you’re planning renovations, even small ones, it’s a great time to think about how you can make your home more resistant to hot summers.

Insulate your walls

Heat travels through walls, and insulation slows the heat down. Walls are difficult to insulate, so it’s best to do it while you are renovating. If you need to replace the lining or cladding of any walls, install insulation at the same time.  

Incorporate thermal mass

Talk to your Scorecard assessor about renovations, and about how ‘thermal mass’ (bricks, tiles and concrete) in the right place can help keep your house cool. 

Upgrade your windows

Windows let a lot of heat into your home on hot days, particularly if you have no way of shading them from the outside. Glass and frames, particularly metal frames, both conduct heat. Double glazing will not prevent heat entering your house if the sun directly hits the glass. 

Deciding whether to replace windows is a complex matter, with a lot of factors to consider. A Scorecard assessor can help you figure out what kind of window and frame solutions will make the most sense for you.

  • Keep doors closed between the hotter and cooler parts of your home, and spend as much time as possible in the cooler parts. Your Scorecard assessor can help you identify which parts of your house are easiest to keep cool.
  • Keep the sun off windows and west facing walls.
  • Use fans before turning on the air conditioning as fans are cheaper to run.
  • When it’s cooler outside than inside, open windows and doors – this will usually be at night or early in the morning before a hot day. Use an indoor/ outdoor thermometer to check when it is time to open the house.
  • Avoid using the oven and stove on hot days – have a barbecue outside if you can or use the microwave.
  • Clothes dryers can pump a lot of hot air into a room, so dry clothes in the sun. 
  • Halogen lights also generate heat, so switch them off (and replace them with LEDs when you can).
  • Only cool the room you’re in, not the whole house, to keep energy use down.
  • Clean the filters regularly to improve efficiency.
  • If you have ducted cooling, get the ducts cleaned and insulated so they don’t leak cool air.
  • If you’re buying a new cooling device, look for one with lots of stars – it will be more energy efficient and cost less to run.

Your building shell

The building shell consists of the roof, walls and floor of your home, as well as windows and insulation. The materials used to build your home all have different properties. Some allow heat to move through them easily, others help retain heat. How well your home is sealed is another factor that determines how much it costs to heat and cool and how comfortable the house is to live in. 

About your home’s building shell 

There are four parts to look at to improve the building shell. The improvement options on the certificate will highlight the weaker elements of your home. 

  • insulation, which acts to slow the rate of heat transfer through a material or building element, helping to keep the inside of your home warm in winter and cool in summer.  
  • thermal mass, which affects the rate your home heats up and cools down. Materials like concrete and brick have high thermal mass and help to slow down the rate that a room may heat up or cool down. 
  • windows, which have the combined function of letting in light and allowing heat movement in summer and winter. 
  • air leakage, which occurs through any gaps between the inside and outside of your home. These include deliberate openings like wall vents and chimneys, as well as gaps and cracks that develop over time.

Ceilings and roofs 

  • Between 25 and 35 per cent of heat loss or gain occurs through the ceiling. Adding ceiling insulation will make a huge difference to the comfort of the home, helping to keep it warm in winter and cool in summer.
  • If the ceiling space is easy to access you can add or top up insulation so that you have a minimum of R3.5. If the ceiling space isn’t easy to access, consider adding insulation when the roof needs replacing or install an insulated false ceiling below the current one.


  • Between 15 and 25 per cent of heat loss and 25 to 35 per cent of heat gain occurs through walls. Walls are difficult to insulate, so it’s best to do it while you are renovating and can replace lining or cladding.
  • Most stud walls have a 90 mm stud that allows insulation up to R2.5 to be installed. Alternatively, wall cladding is now available that can be retrofitted internally or externally that includes an insulated layer.


  • Between 10 and 20 per cent of heat loss or gain occurs through floors. Insulation is most effective on floors that have a large space underneath – and these are also often the most accessible. Raised floors are generally timber floors that can be insulated using batts or insulating boards affixed between the joists.
  • Slab on-ground concrete floors can’t be insulated after construction, so insulating the slab is only an option for new homes.
  • Installing insulation should be done in accordance with the Australian Standard (AS3999:2015) and the wiring rules (AS/NZS 3000:2007) to ensure it is done safely and will give the best possible results.

Appropriately installed thermal mass inside your home can make it more comfortable. High thermal mass elements, such as brick, rammed earth, tile and concrete, tend to be slower to change temperature than low thermal mass elements. In winter, thermal mass exposed to the sun or your heater will mean your home remains comfortable for longer. In summer, thermal mass connected to the ground or other cooling sources will mean your home remains comfortable for longer. Thermal mass should be positioned so they are exposed to sun in winter but shaded from sun in summer.

It is very important to understand how to make your windows work to your benefit. While 10 to 20 per cent of heat is lost through windows in winter, the potential for heat gain in summer is much higher at between 25 and 35 per cent. There are many ways to manage windows to make your home more comfortable, including replacement or improvement.  

Windows have three important properties:  

  • insulation
  • letting the sun in (light and heat)
  • ventilation

Even the best performing windows will not insulate your home as well as an average wall. This means that windows can be a major weak spot, letting heat out in winter and heat in during summer. Both the frame and the type of glass effect the performance of windows.

For many homes the best way to improve comfort and save on your energy bills is to deal with gaps, cracks and other points that allow draughts. Between 5 and 25 per cent of heat loss or gain is due to gaps and cracks. Draughts also create airflow over your skin which make you feel colder in winter. 

If your home has fixed ventilation, such as ceiling or wall vents, only remove it after seeking expert advice. Wet areas often need ventilation to avoid mould. You may need to install alternative ventilation such as exhaust fans. 

Target these areas for sealing: 

Exhaust fans

Exhaust fans should have louvres or flaps that close when not in use to reduce unwanted air leakage. If you can’t do this, try to keep doors closed to these rooms. You may even consider draught proofing internal doors if a room is a particular problem. 


Chimneys for open fires can cause large amounts of air leakage. If you want to use your fireplace, you can fit a damper that blocks the chimney when it’s not in use.  

You can block the chimney permanently if you don’t intend to use the fireplace. Often it is good to block the fireplace from the bottom or within the room. If the blockage is visible someone is less likely to try to use the fireplace in future. 

Door and window seals

It is very common that windows and external doors are a source of draughts.  Signs are that windows rattle, dust accumulates around the inside of the inside of the frame or you feel cold air movement in winter.  If you can see light around a door this indicates a big problem. 

There are many window and door seal products available that are suitable for different situations. If you’re looking for a less-permanent solution, you can stop gaps at the bottom of doors with a door snake. 

Gaps can also occur around the outer edges of the frames where they meet the wall. These can be sealed with caulking and painted over. 

Wall vents, ceiling vents and vented skylights

Homes built before the mid-1980s often incorporated wall or ceiling vents. You can seal or remove these vents unless you intend to use a portable un-flued gas heater or an open-flued gas heater in the room. Never use a portable gas heater in a sealed space. 

Vented skylights incorporate a permanent opening, usually covered by flyscreen or mesh. These are generally found in bathrooms and laundries. You can replace the skylight with a new type of sealed roof window or install a sheet of acrylic at the bottom of the shaft that blocks the entire hole. 

A cheaper option is to close the door to the area with the venting. You may even consider draught proofing internal doors if it is a big problem. 


Older style incandescent downlight fittings and gimballed (swivel) halogen fittings allow significant amounts of air leakage.  

You can replace these with high-efficiency, sealed LED fittings that reduce air leakage, as well as energy use. 

Floorboard gaps

Older floorboards may develop gaps between them and allow air leakage. Floorboards tend to shrink, expand and bend when walked on, causing fillers to fall out. This is a difficult issue to solve. The simplest approach might be to install carpet or rugs. 

If the under-floor space allows it, you can insulate the floor from below with a product that provides an air seal like foil or insulating boards. 

Skirting board gaps

Air leakage can occur in gaps between the skirting and the floor, especially in older homes. On a raised timber floor, there is likely to be significant leakage. 

These gaps can be addressed by using a flexible caulking material, or you can use a foam noodle or filler on large gaps.

Heating and cooling


Central and space heating

Centrally heated homes generally have most of the home heated, for instance by gas ducted heating. Space heated homes often have only one or two rooms heated using an appliance like a wall furnace. Space heating usually costs less to run than central heating, but comfort levels in unheated rooms can be lower. 

Reverse-cycle space heating

As well as providing cooling in summer, reverse-cycle air conditioners can be very effective and efficient space heaters. 

Most reverse cycle space heaters have a star rating. When purchasing, look for an appliance with 4 stars or more. Using multiple reverse-cycle systems can actually be more efficient than installing central heating as there are no ducts through which heat can be lost. 

See for a list of models and their ratings.

Gas space heating

Gas space heaters can be very effective and efficient heaters. These can be in the form of floor-mounted console heaters, wall furnaces, gas faux fires and other designs. 

These heaters have a star rating. When purchasing, look for an appliance with 5 stars or more. Again, installing multiple systems may be more efficient than central heating. 

See the Australian Gas Association list of current models and their energy rating:

Ducted heating

Many houses have a large reverse-cycle air conditioner or gas heater to provide heating to the whole of the house. These produce hot air in a central module, which is pumped along ducts to either floor or ceiling vents. However, ducted heaters lose heat from the ducts while the warm air is on its way to where you want it. If your system allows it, zoning your house is an effective way of heating the areas that are used more frequently like the living areas, while closing the ducts to the bedrooms until required. 

If you’re looking for a gas system, choose appliances with a rating of 5 or 6 stars. 

Some electric ducted reverse cycle systems have star ratings. Choose the highest star rating possible. 

Ductwork should be regularly checked by a tradesperson to ensure there are no leaks. If you have an older system, the ducting is unlikely to be insulated. Consider upgrading the ducting along with the heater. 

Hydronic heating

Hydronic heating systems that circulate hot water or coolant through radiator panels or the floor can be very cheap to run if an efficient hot water system is used to heat the water. For efficient use of hydronic heating, all radiator room panels should have their own thermostat controls, so you can choose which rooms to heat. 

Ensure that water circulation pipes are well insulated and that there is insulation behind the radiator panels. This could be in-wall insulation or a reflective surface behind the panel. This is particularly important for external walls.


Reverse-cycle air conditioners (single room)

Reverse-cycle air conditioners are efficient coolers – with the added bonus they can also be used as a heater in winter. 

When purchasing, look for an appliance with 4 stars or more. See for a list of models and ratings.  

Reverse-cycle ducted air conditioner

Large air conditioning modules can be installed centrally to provide ducted cooling. They have the same disadvantage as ducted heating, in that you will lose cooled air from the ducts, and your system may not easily allow zoning to occur within the house. 

Evaporative cooling

Evaporative coolers provide cooling using the evaporation of water rather than a refrigeration process. These can be single room units or a central system. 

They can use much less energy than typical air conditioners, but they do use water. They are also less effective in humid weather and require windows or doors to be left open to allow air flow. 

Evaporative systems don’t fall under the star rating system for appliances but are generally very efficient to run.

Hot water

Hot water systems often use a significant amount of energy and can make up a large proportion of electricity or gas bills. 

The number of people living in your home, the location of the hot water system, whether or not you have a solar electricity system, the availability of natural gas and how you use hot water in your home all impact on the cost of water heating.

Hot water system types 

There is a range of hot water system types in the market, with the main ones being gas, electric, solar, heat pump and wood fuel systems. These are explained below. 

The Scorecard certificate may suggest upgrading to a high efficiency electric heat pump, gas or solar system as these are the most efficient systems available. 

Gas systems

Gas hot water systems can be a good option, especially if you have mains gas. Instantaneous, or continuous flow, gas hot water systems heat only the water that you require as they don’t have a storage tank. Some models let you control the delivery temperature, and these can be different in different parts of the house, which provides safety advantages. 

These systems can be a good choice if you have variable hot water use as you will always have enough hot water. Instantaneous systems often require large gas pipes, which can increase the cost of installation. 

Gas storage hot water heaters store hot water in a tank. Storage systems can be inefficient because of the energy lost through the walls of the tank. You may find you run out of hot water if the system is undersized or are heating too much water if it is oversized. 

Gas hot water systems have a star rating. Try to choose a system with 5 or more stars if you are upgrading. 

A list of current models with star ratings is available from the Australian Gas Association:  

Electric systems

Electric hot water storage systems can be very costly to run, due to a combination of the energy required to heat the water and the energy lost during storage. Also, systems under 250 litres must run on peak rates. This applies to most flats and smaller homes and can be very expensive to run. Larger units over 250 litres usually to run on off-peak electricity and heat up overnight, which is generally cheaper. 

Electric instantaneous systems are generally more efficient than electric storage heaters, and modern models have better temperature control than older models. These units usually require dedicated wiring due to the high currents involved, so may be more costly to install. 

If you have a solar PV system you can offset some the energy that electric hot water systems use, making electric systems cheaper to run. 

There is no star rating system for electric water heaters. 

Solar hot water systems

Solar hot water systems are an efficient way to heat water. Depending upon the time of year, most of your water can be heated free by energy from the sun. 

Solar hot water systems use solar collectors, either flat panels or glass tubes, to heat the water. The hot water is then stored in a tank, which may be on the roof or on the ground. 

Solar hot water systems will usually need boosting from another energy source on cloudy days and cold nights. Boosting can be from gas, electricity, or sometimes wood fuel. You can even retrofit a solar system to some existing hot water systems. 

There is no star rating system for solar water heaters. 

Heat pump systems

The are some very efficient heat pump systems on the market. Heat pump systems have a storage tank and use a similar principle to your refrigerator. Instead of pumping heat out of the fridge to keep it cool, they pump heat into the water. They use electricity far more efficiently than a traditional electric water heater. 

Consider changing to a heat pump if you have a photovoltaic (PV) solar system or intend to install solar in future. You can offset some the energy used by the heat pump with the solar system. 

There is no star rating system for heat pump water heaters. Place the heat pump unit away from windows as some models can be noisy. 

Wood fuel systems

Wood fuel systems are occasionally used to heat water, often as part of heating the home. These are more often found in rural areas where wood fuel is plentiful and mains gas is not available. 

The performance of wood fuelled systems can be highly variable. The type and quality of fuel, the age and maintenance of the system all impact on efficiency. Wood fuel must also be cut and stored appropriately. It is very important to manage air quality impacts by operating the system efficiently as smoke can be unhealthy and inconvenient for you and your neighbours. 

For further information see:

Download our fact sheet: hot water improvements (.PDF, 245.0 KB)


The most common forms of lighting found in homes are light-emitting diodes (LEDs), fluorescent lamps and halogen lamps.

Incandescent (tungsten filament) lamps were the most common form of lighting for decades but have been phased out over recent years to be replaced by more efficient types of globes.

These can either be recessed into the ceiling (downlights), ceiling-mounted (pendant or track lights) or wall-mounted lights (sconces or track lights).

Light Emitting Diode (LED)

LEDs are highly efficient lamps with a very long life.

LEDs come in many forms and can replace existing lamps in general-purpose lighting fixtures (for example, bayonet or Edison screw) or downlight fittings.

LEDs also come in many colours of light. Unless you want party lights, you will probably want to install “warm white” lamps that are similar to the colour of the older style incandescent lights. If you need more clarity for fine work or definition of objects, you may wish to use “cool white” coloured lamps.


Fluorescent lamps are also very efficient and have only recently been surpassed by LEDs.

Fluorescents can take the form of tubes, circles or more compact forms that can be used in general purpose fittings.

Compact fluorescent lamps (CFLs) can be used as replacements in general-purpose lighting fixtures, although size constraints can limit the style and brightness of CFL you can use.


Incandescent globes are now rarely found in general fixtures, but are more common in specialised fixtures such as chandeliers or outdoor floodlights.

Incandescent lamps are inefficient, typically using 6 or more times the energy of an LED and can generally be replaced with LEDs or CFLs.


Halogen lamps are most often found in recessed downlights or track lighting, but there are also versions available to use in general light fixtures.

Halogens typically use 6 or more times the energy of an LED and generate a large amount of heat both in the room (and in the roof cavity with recessed lights)

Colour temperatures

“Cool white”, “warm white” and “daylight” are variations of colour. The colour is measured in degrees Kelvin (shown by the letter K). All LED and CFL lamps have their colour written on the packaging so you can check before purchasing.

Here are the typical ranges for each colour temperature:

  • Warm white – 2000K to 3000K
  • Cool white – 3100K to 4500K
  • Daylight – 4600K to 6500K

Recessed light fittings

Most older style recessed downlights bring a few different issues to the energy efficiency performance of the house.

If they contain halogen lamps (MR16 model code), they will be using a lot of energy.

Halogen lamps also generate a lot of heat which contributes to over-heating the room on hot summer days. For the same reason, insulation must be kept well clear of the part of the light fitting that protrudes into the roof. This means that the ceiling insulation in rooms with many recessed fittings is likely to perform poorly. Even small gaps in insulation can lead to a large drop off in efficiency.

Gimballed downlight fittings (those that have an adjustable centre piece) and the larger style of recessed light common from the 1970s and 1980s often have significant gaps to allow heat from the lamp to escape. These gaps also allow air leakage from the room below in winter and from the roof cavity into the room in summer.

Track lighting

Older styles of track lighting (downlights) may still contain halogen lamps (GU10 model code) which use a lot of energy. Track lighting does not have the same problems as recessed downlights in terms of gaps around the lamp or in insulation because they are attached to the underside of the ceiling.

Improving lighting performance

Replace ceiling- and wall-mounted lamps with LED lamps. These are widely available through supermarkets, hardware and lighting stores. They will give you an instant reduction in energy consumption.

When replacing recessed fittings there are four options:

  • Replace the lamp in the existing fitting. Note that when replacing low-voltage halogen lamps (known as MR16 or 12-volt lamps) with LEDs, there may be incompatibilities between your existing transformer and the LED lamps. This can lead to poor performance or flickering. This option will not solve the issue of gaps in insulation or air leakage through the fitting.
  • Replace the transformer and the lamp. This will not solve the issue of gaps in insulation or air leakage through the fitting.
  • Replace the whole fitting with a sealed LED unit. New fittings have ratings that either allow insulation to be placed against the sides (CA90 rated) or over the top of the fitting (IC4 rated).
  • Replace recessed fittings with non-recessed fittings such as track lighting, pendant lighting, ceiling-mounted or wall-mounted lighting.

Consult your electrician for advice on the requirements for fittings and insulation.

Other considerations for lighting use

Ways to cut lighting power bills:

  • Turn lights off in rooms when not in use.
  • Use task lighting (reading lamps) and turn off the main lights in the room.
  • If night lights are required for small children or in stairwells, ensure low wattage sensor lamps are used, rather than leaving a room light on.
  • Light coloured surfaces reflect more light so if repainting is required, choose a lighter colour for ceilings and walls.
  • If you are renovating, consider placing new lighting circuits that allow you to choose which lights you have on in a room. The more flexibility you have to turn some lights off, the lower your energy costs will be.
  • Check to see if there are any government funded schemes that will change your light bulbs to more efficient ones.

Download our fact sheet: lighting improvements (PDF, 264.0 KB)

Page last updated: 13/10/20