Foil Insulation: What you need to know

Foil insulation was once the most common material used for underfloor insulation in New Zealand. The performance of underfloor foil is dependent on how well it is installed. The air gap between the floor and the foil needs to be well sealed which is very difficult to achieve. Any air movement between the floor and the foil will reduce the foil's effectiveness, as will dust settling on the foil over time, which reduces its reflectivity. Foil insulation can also be damaged easily, e.g. by wind or cats. (Source: EECA).


Ban on the installation and/or repair of foil insulation

Damaged foil will need to be replaced with bulk insulation as you are not allowed to repair foil insulation in residential buildings. Under section 26 of the Building Act 2004, a ban has been placed on installing foil insulation into residential buildings with existing electrical installation (retrofitting foil insulation), and the repair of foil insulation that has been damaged in any way. The ban is due to safety concerns about electrocution due to a number of factors, including the conductivity of the foil and the chance of staples puncturing live wires. Anyone who breaches this ban may be liable to a fine of up to $200,000.


Replacing foil insulation

Replacing, repairing and removing foil insulation can be very dangerous – there is a serious risk of electrocution if the foils or staples at any point come into contact with live electric wires under the house. Our staff are trained in safe foil removal, and can accurately test under your house for live electricity using a volt meter. If necessary, we will ask you to turn the power off in your home during the foil removal/bulk insulation installation process.


More information

For more information, please see the following links:



Community Energy Action


(0800 438 9276)

+64 3 374 7222


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