Separating wall
A separating wall divides two attached Class 1 dwellings and must meet NCC FRL requirements. Key rule: runs from footings to roof, not just ceiling height.
Ask Chalkline about this →A separating wall (also called a party wall or common wall) is the shared wall dividing two attached Class 1 dwellings, such as a duplex, townhouse, or semi-detached house. Under NCC 2022, it is a fire-rated element required to stop fire spreading between dwellings.
Under the ABCB Housing Provisions Standard 2022 (Part 9.3), a separating wall must achieve an FRL of 60/60/60 or be masonry at least 90 mm thick. Critically, it must start at the footings or ground slab and extend either to the underside of a non-combustible roof covering or at least 450 mm above a combustible roof: stopping at ceiling height is a common compliance miss (verified 2026-05-07).
Service penetrations through a separating wall require construction rated at FRL -/60/60, and openings for electrical cables are limited in area.
Also known as: party wall, common wall.
Category: Compliance & approvals.
Related
- NCC fire separation, the Part H3 requirements that govern separating walls
- FRL, Fire Resistance Level notation used to specify separating wall performance
See also
- NCC 2022 Volume Two
- Plasterboard, common lining used to achieve FRL in separating walls
Last updated: 2026-05-07. Verified: 2026-05-07. Quarterly review for currency.