Good insulation means a significant reduction in the rate of heat loss in your house via ceilings, walls, floors, windows and doors.

This reduced rate of heat loss makes the house easier and cheaper to heat properly. This means the house will be healthier and more comfortable to live in.

Heat is lost from the inside of the house in two main ways:

• Air infiltration – hot air escapes from the house through cracks, gaps, holes, and open chimneys. This is replaced by cold air.

• Conductivity – hot air escapes directly through the elements of the house such as walls, ceilings, floors, windows and doors.

If your house is draughty, any insulation you install won’t be able to do its job properly.

It’s important to minimise the amount of air leakage from your house at the same time as you improve the insulation.

Heat always finds the easiest path out of a house. If you insulate one part of your house, the ceiling for example, you reduce the rate at which heat is lost through the ceiling.

But the rate at which it escapes through other parts of the house increases. To get best results you need to increase the insulation for all of the outside building elements of your house.

The following is the sensible order in which to install insulation:

• Insulate your ceiling first. Heat rises. In an uninsulated house the majority of heat is lost through the ceiling

• Next, insulate under your floor. If the floor is cold, you feel cold.

• Walls and windows are both relatively difficult and expensive to insulate in an existing house. These are jobs normally left for when individual rooms or a whole house is being renovated. If you need to remove wall lining in your house, you can install wall insulation. 

• Insulate, too, when replacing windows.