Fire spread from lower roofs

The distinct risks around fire presented by medium density developments have been highlighted as an important area of focus for the programme. A first piece of work in this space looked at risk of fire spread in medium density housing projects where there are different roof heights in the same building.
Lead organisation
BRANZ Limited
Focus area
Resilience
Start date
Status
Complete
Last updated 23 Apr 2026
Share

About this programme

The distinct risks around fire presented by medium density developments have been highlighted as an important area of focus for the programme. A first piece of work in this space looked at risk of fire spread in medium density housing projects where there are different roof heights in the same building. This is a common design element of medium density housing. The challenge is around the risk of fire spreading from the lower roof onto the higher wall above it. At present these higher walls must be protected to prevent the spread of fire, which is both onerous and expensive. This project identified more efficient, lower-cost ways of preventing fire spreading from lower roofs which allow greater architectural freedom while meeting Building Code requirements.