Filtering light into your home from above gives dark rooms a lift and saves you money, writes Sarah Pickette.

Many households have a room that's too dim during the day. It's easy to flip a light switch when you want to use this space, but investigating ways to capture more natural light could pay dividends in the long run. Lighting usually accounts for about 10 per cent of household energy usage and potentially more if you rely on artificial lighting all day. For an alternative, look to the sky.

Today, most skylights have the same energy-efficiency features, in terms of glazing and thermal transmittance controls, that you'd find in new windows. And by virtue of its positioning, a skylight can admit more than three times as much light as a vertical window of the same size.

Although a skylight may allow some thermal energy to be lost to the roof space, and can add to the heat load in summer, the burden imposed rarely amounts to more than a few per cent of the total energy required for heating and cooling the home. This compares to 20 to 30 per cent for typical windows, according to the Federal Government's Your Home technical manual for environmentally sustainable building.

Architect Marcus O'Reilly has five skylights that extend over the kitchen and dining areas of his Melbourne home. "In the case of my house, the skylights are shaded for most of the day by an upper-storey extension, so they don't get the full blast of the sun. They allow a lot of sunshine in for a short period in the morning and again in the afternoon. It's really pleasant."

However, it is important to think about heat gain and loss when you consider skylights, he says. "Double glazing is essential."

Another option to consider is a tubular daylighting device (TDD). This works by admitting sunlight via a rooftop dome. The light travels via reflective tubing down through the roof space to a diffuser that's set into the ceiling.

"The diffusers look similar to a standard light fitting and you won't have heat loss and gain issues," says Mark Peall, General Manager of Solatube Australia, a provider of daylighting systems. Installing a TDD, says Peall, could cut your interior lighting needs by 80 per cent and save up to 8.6 kilograms of carbon emissions annually.