How Much Insulation Do I Need With A Heated Floor?

The Building code of Australia sets out minimum insulation requirements for any new home. However, you might choose to install more insulation because it will reduce the running costs of your heating system.

The easiest places to start with additional insulation are walls and ceilings. If your home has a ceiling cavity, it’s easy to add a bit of extra insulation in there.

Walls are a little more problematic, as many houses are constructed with 90mm thick walls, which don’t have much space for extra insulation. Increasing the thickness of the walls is often expensive due to the extra cost of building materials required.

Your windows are usually the biggest source of heat loss, especially in new homes with large areas of glass. If you have big windows, then consider double- or triple-glazing for your windows. Also consider thermally broken windows frames as ordinary frames can lose a lot of heat.

If you’re heating your slab, it’s a good idea to include some extra insulation there too. Many houses are built with 100mm polystyrene underneath – with a heated slab it’s a good idea to double this thickness, or use a higher density and better insulating foam product.

It’s also a good idea to insulate the edge of the slab, rather than leaving it exposed to outside (you don’t want to be spending money heating your front yard!) How easy this is to do in practice will depend on how your house is designed and built. Talk to your architect or builder about how they’re constructing the slab and how they intend to insulate it. If necessary, we can provide assistance and advice on this matter.

Also think about thermal drapes rather than standard blinds. Most of your heating costs will be incurred at night, so closing the curtains may be an appropriate option. However, if you’ve got a fantastic night time view that you want to be able to see, then it’s a good idea to improve the insulation quality of your windows so that your view doesn’t cost you extra money while your heat is escaping through the glass.

If you’re building soon and you’re not sure what sort of insulation you should be installing, get in touch and we’ll be happy to help answer your questions.