BRANZ Guideline January 2012 retrofitting of insulation to external walls requires a building consen

Issue 35 – February 2012

Before fitting any insulation material into exterior walls, a building consent must be obtained before the work is started.

Schedule 1 of the Building Act, which lists the work that does not require a building consent, says in clause (jg) that: 'Insulation may be fitted to walls of an existing building except:

a) external walls

b) internal walls that are fire separation walls'.

Fitting of insulation to existing external walls may have implications for weathertightness, structural bracing, and wiring condition. Insulation fitted to an existing fire-rated wall may adversely affect fire safety properties.


Published in building.