Home › NZ Building Code › Linings & GIB › GIB Intertenancy
NZ Building Code · Linings & GIBGIB intertenancy barriers for attached dwellings
Intertenancy barriers are the separating walls between attached dwellings that have to stop both fire and sound crossing from one unit to the next.
Intertenancy barriers are the separating walls between attached dwellings — terraces, duplexes and multi-unit blocks. They have to do two hard things at once: stop fire spreading unit-to-unit, and stop sound carrying through — so if you’re building attached homes, this is the wall you can’t get wrong.
How the system does both jobs
The trick is a central rigid barrier plus a double, decoupled frame working together:
- The barrier — 25 mm GIB Barrierline — gives you the fire rating.
- The air gap between the two separate frames kills the vibration path that would otherwise carry your neighbour’s TV straight through.
System options (2023 update)
The current GIB intertenancy systems, all rated 60/60/60, are:
- GBSLAB 60a (STC 61) — steel-framed intertenancy with Barrierline.
- GBSLAB 60b (STC 67) — the premium acoustic version.
- GBTL 60b LB (STC 42–50) — the timber-framed alternative.
Barrier and framing details
The build-up that makes these systems work:
- 25 mm Barrierline (water/mould resistant) as the central barrier — supplied in 600 × 3000 mm sheets only.
- Barrier height 12 m maximum.
- GIB H-Studs in Rondo 140 perimeter channels on the steel-framed systems.
- Wall clips and straps at 600 mm centres.
- 90-day maximum weather exposure.
Plain-English guide, not advice. This page helps you understand and navigate the rules — it is general information, not design, engineering or consent advice, and it does not reproduce the copyrighted tables of NZS 3604 or any Standard. Always check the current Standard or Acceptable Solution and your BCA, and use a suitably qualified LBP, engineer or QS where it matters.
Do it in Toolie
Put this into practice with the GIB calculator · the builder calculators. Try Toolie free — no signup — or open this topic in the Toolie app.
Common questions
What is an intertenancy barrier?
It’s the separating wall between attached dwellings — terraces, duplexes and multi-unit blocks. It has to do two hard things at once: stop fire spreading unit-to-unit and stop sound carrying through.
How does a GIB intertenancy system stop both fire and sound?
It uses a central rigid barrier (25 mm GIB Barrierline) plus a double, decoupled frame. The Barrierline gives the fire rating, and the air gap between the two separate frames kills the vibration path that would otherwise carry sound through.
What are the current GIB intertenancy system options?
As of the 2023 update: GBSLAB 60a (60/60/60, STC 61), a steel-framed system with Barrierline; GBSLAB 60b (60/60/60, STC 67), the premium acoustic version; and GBTL 60b LB (60/60/60, STC 42–50), the timber-framed alternative.
What are the key limits on the Barrierline barrier?
The 25 mm Barrierline is water/mould resistant and comes in 600 × 3000 mm sheets only, with a 12 m maximum barrier height, wall clips and straps at 600 mm centres, and a 90-day maximum weather exposure.
More in Linings & GIB
Quote it, comply, get paid — in one app
Toolie turns this knowledge into the job: NZS 3604 take-off, H1 & Healthy Homes, consents, retentions and invoicing — one flat NZD price.
Quote a job free →