Heat will always be lost from a warm area to a cold area, and in a house without cavity wall insulation around a third of the heat created inside can be lost through the external walls.
The vast majority of houses constructed after 1924 have external walls consisting of two layers of brick or block work with a gap, or cavity between them. However, it was not until the 1970’s that cavity wall insulation became widespread and not until the early 1980’s that improved insulation qualities demanded by Building Regulations effectively made it compulsory.
Installing free cavity wall insulation will help reduce your heating bills
The material used in cavity wall insulation fills the gap between the outer and inner skin of the external walls and this helps to reduce heat loss and save energy. By installing cavity wall insulation in a house without any, householders can save over £275 per year in energy bills. (According to the Energy Saving Trust).
Are cavity walls better than solid walls?
A home built with cavity walls will generally be better insulated and suffer less from condensation than one built with solid walls.
Properties constructed with solid walls will still normally have two layers of brick or block but will have little or no cavity between the two skins of brickwork.
Most homes in the United Kingdom have exterior walls with a cavity between two skins of brick work or block work and cavity wall insulation fills that gap, which helps to keep in the warmth, saving energy and reducing your energy bills.
Free cavity wall insulation can also help to reduce condensation inside your home if this is a problem on your external walls. In general terms, the need for cavity wall insulation will probably apply to your home if:
• The property was built after 1924 but before 1983
• The external walls have a cavity more than 40 mm wide and it is not currently filled
• The brick work or block work is in good condition
• The walls are not exposed to driving rain
A registered installer can carry out a boroscope inspection to determine whether your home already has cavity wall insulation. This involves drilling a small hole in the external wall and using a camera to check if the cavity is empty or filled.