Description

Controlling fire spread between residential buildings and outbuildings is important for protecting life and property. We recap the requirements and look at an area of confusion – fire rating of windows and doors in walls close to a boundary.

BRANZ HELPLINE calls suggest that misunderstandings remain about the fire resistance rating (FRR) requirements for walls less than 1 m distance from the boundary but at an angle of 90° or greater to the boundary.

Scope

This article includes:

• Acceptable Solution C/AS1
  • Sprinklers change external wall requirements
  • Check walls under 1 m from boundary
  • Windows and doors
  • Multi-unit dwellings
  • Protecting eaves
  • Attached buildings
  • Exterior surface finish requirements
• No FRR needed for some open structures
• Select notional boundary that works best
• Treat alteration work as a new build
  • Cannot simply replace windows like for like
• An alternative is to add more light
• The topic is a complex one