Winter is fast approaching and it's nearly time to pull out the winter woollies, stock up the firewood pile and switch your air-conditioning unit from a cool cycle to a warm cycle. It may also be a time when the rising dread of increased electricity bills becomes all too real for many homeowners.

With the cost of electricity continuing to rise in Australia, it makes good financial sense to invest in home improvement projects that will help to make your home more energy efficient. Here are two of the best projects to invest in that will help to keep your electricity bills low this winter and for many more winters to come.

1. Install insulation

New homes in Australia are generally very well insulated and have to meet strict minimum national guidelines for energy efficiency. If your home is more than a decade old, there's a good chance that it's under-insulated or has no insulation at all. Retrofitting insulation is the most effective way of keeping your home warm in winter and reducing your heating costs.

The key to effective insulation is to make sure that it's installed in the right places. The roof is the most obvious place, and insulation there will prevent warm air from escaping as it naturally rises to the ceiling. Walls are the next problem area, and these can be insulated by adding a spray insulation into the wall cavities with minimal mess and damage to the walls.

2. Winter-proof your windows

Glass is one of the best conductors of heat, and this makes windows one of the biggest culprits for heat loss during the winter months. Ideally, replacing your single glass panels with double glazing is the most effective way to make your windows more energy efficient. The air-filled space between the panes creates a powerful buffer that prevents heat transference.

If double glazing is out of your current budget range, then adding an insulating film to the surface of your windows is the next best option. This high-tech film can be applied to both the interior and exterior of your windows to provide you with a dramatic reduction in heat loss.

Although not as effective as double glazing, insulation film will still give you a great improvement for a fraction of the cost. It can also be used in conjunction with double glazing for windows that have an incredibly low heat transference rate.