🇦🇺 Australia · NCC 2022 Part F7 · Apartment Acoustic Compliance
NCC 2022 Part F7 — Acoustic Flooring for Australian Apartments
In Australian multi-storey residential, the floor is an acoustic component. NCC 2022 Part F7 (the section renamed from Part F5) sets the airborne and impact sound limits a separating floor must meet — and getting the specification right is what keeps a project off the building surveyor’s non-conformance list. This guide explains the numbers, where SPC fits, and the one thing most product datasheets get wrong.
Short answer
For Class 2/3 apartments, NCC 2022 Part F7 requires a separating floor to achieve airborne Rw + Ctr ≥ 50 and impact Ln,w ≤ 62 (AS ISO 717.2). Crucially, that rating belongs to the whole floor-ceiling assembly — concrete slab, ceiling, and flooring together — not to the floor covering alone. SPC with an IXPE backing contributes to the impact result, but the compliance number comes from a NATA-accredited test of the actual build-up.
Reviewed June 2026 · ABCB NCC 2022 Volume One Part F7 · AS ISO 717.2 · AS/NZS ISO 717.1 · General guidance, not acoustic or certification advice.
Why F7 drives flooring specification
The floor is part of the acoustic system
Australia’s apartment boom in Sydney, Melbourne and Brisbane made impact noise — footsteps, dropped objects, furniture — one of the most common sources of resident complaints and, increasingly, building defect claims. The National Construction Code responds with mandatory sound-insulation requirements for floors separating sole-occupancy units in Class 2 (apartments) and Class 3 (hotels, accommodation) buildings, set out in Part F7 of NCC 2022. The same provisions were previously numbered Part F5; the requirements carried over when the code was restructured, so older specifications referencing “F5” are pointing at what is now F7.
Because a bare concrete slab transmits impact sound efficiently, a resilient floor finish — or an acoustic layer beneath it — is usually needed to bring the assembly within the impact limit. That is precisely where SPC flooring with an IXPE acoustic backing earns its place in the Australian residential market: it contributes to the impact performance of the assembly while delivering the rigid-core durability apartments need.
The two metrics
What Part F7 actually requires
Part F7 controls two different things — airborne sound (voices, TV) and impact sound (footsteps) — with two different metrics. For a floor separating apartments, the Deemed-to-Satisfy provisions require:
Airborne sound
Rw + Ctr ≥ 50
Weighted sound reduction with the low-frequency spectrum adaptation term Ctr, determined under AS/NZS ISO 717.1. The Ctr term penalises poor bass performance — it can subtract 3–8 dB on lightweight construction.
Impact sound
Ln,w ≤ 62
Weighted normalised impact sound pressure level, determined under AS ISO 717.2 from laboratory measurement (in-situ, the field metric LnT,w ≤ 62 applies). Lower is better — it is a “not more than” ceiling.
There is also a Verification-Method path (F7V1) that allows compliance to be demonstrated by in-situ testing, requiring a measured DnT,w + Ctr ≥ 45 for airborne and LnT,w ≤ 62 for impact on the finished floor. Either way, the impact ceiling that matters for flooring specification is Ln,w ≤ 62.
A note on the number 62: the UK’s Approved Document E uses a similar-looking impact figure, but the metric and test standard are not the same — Australia assesses impact under AS ISO 717.2, and a report prepared for another country’s standard is not automatically accepted by an Australian certifier. Always work from AS ISO 717.2 data for an Australian project.
The critical point most datasheets miss
The rating belongs to the assembly, not the plank
This is the single most important thing to understand about F7 — and the thing flooring datasheets most often get wrong. The Ln,w figure is a property of the complete floor-ceiling assembly: the concrete slab, any acoustic layer, the floor finish above, and the ceiling and services below, all tested together. A “â–³IIC” or impact number printed on a flooring product is an improvement contribution measured on one specific lab build-up — it is not the compliance value for your building, and it cannot be added to a slab rating to predict the result.
SPC floor finish + IXPE backingcontributes to impact reduction
Acoustic underlay (if specified)project-dependent
Concrete slabthe primary mass element
Ceiling void + servicesflanking paths live here
Suspended ceiling belowpart of the rated system
Independent post-construction testing in Australia has repeatedly found a high proportion of separating floors and walls failing to meet the NCC limits on site — even when the components passed in the laboratory. The usual culprit is flanking transmission: sound travelling around the separating element through the structure, junctions and services, which a laboratory element test does not capture. This is why a credible specification is built around a tested assembly and a project acoustic engineer — not a single product number.
Our honest position on acoustic numbers: Ecoflors does not print an Ln,w or IIC figure on a product and present it as an Australian compliance value, because the compliance value is the assembly’s, verified by a NATA-accredited laboratory. What we can do: confirm the IXPE backing specification, provide third-party acoustic test data on request, and arrange testing of a specific floor build-up so your acoustic consultant has real numbers to work from. We would rather give you defensible evidence than a marketing dB figure that a certifier will reject.
Where SPC fits
Specifying SPC for an F7 project
SPC with an IXPE acoustic backing is a common floor finish in Australian apartment specifications because it combines rigid-core durability with a contribution to impact performance. How to specify it sensibly under F7:
| Project stage | What to do | Why |
|---|
| Design / DA | Engage an acoustic engineer; set the assembly target | The engineer specifies the slab, ceiling and finish as a system to meet Rw+Ctr ≥ 50 and Ln,w ≤ 62. |
| Product selection | SPC + IXPE backing; request acoustic data | The IXPE backing contributes to impact reduction; ask for third-party data for the build-up, not a plank number. |
| Verification | NATA-accredited test of the assembly | Compliance is confirmed on the actual build-up (lab Ln,w or in-situ LnT,w / DnT,w+Ctr via F7V1). |
| Construction | Control flanking at junctions & services | Most on-site failures are flanking, not the finish — sealing and detailing protect the result. |
Practical specification language: rather than “SPC with â–³IIC 23”, a defensible spec reads “rigid-core SPC with 1mm IXPE acoustic backing, assembly to achieve Ln,w ≤ 62 per AS ISO 717.2, verified by NATA-accredited test of the proposed build-up.” That puts the obligation on the assembly where the code puts it, and it is something Ecoflors can support with real data.
NCC F7 acoustic FAQ
NCC Part F7 and flooring — questions specifiers ask
What are the NCC 2022 Part F7 sound limits for apartment floors?
For a floor separating sole-occupancy units in a Class 2 or 3 building, the Deemed-to-Satisfy provisions require airborne insulation of Rw + Ctr ≥ 50 (determined under AS/NZS ISO 717.1) and impact insulation of Ln,w ≤ 62 (determined under AS ISO 717.2). A Verification-Method path (F7V1) instead allows in-situ testing showing DnT,w + Ctr ≥ 45 and LnT,w ≤ 62 on the finished floor. The impact ceiling that drives flooring choice is Ln,w ≤ 62.
Is NCC Part F7 the same as the old Part F5?
Effectively yes. The sound transmission and insulation provisions were numbered Part F5 in earlier editions and were renumbered to Part F7 in NCC 2022 when the code was restructured. The substance — the Rw + Ctr and Ln,w requirements for separating floors and walls — carried over. Specifications and older product literature that reference “F5” are pointing at what is now F7.
Does SPC flooring meet NCC F7 on its own?
No product meets F7 “on its own” — compliance is a property of the whole floor-ceiling assembly (slab, finish, ceiling and services), not the floor covering. SPC with an IXPE acoustic backing contributes to the impact result and is a common finish in compliant apartment build-ups, but the Ln,w ≤ 62 figure must be achieved and verified for the actual assembly, typically by a NATA-accredited test. Treat any single product dB number as a contribution, not a compliance value.
What is the difference between Ln,w and â–³IIC on a datasheet?
Ln,w (and the field version LnT,w) is the weighted impact sound pressure level of an assembly — lower is better, and NCC F7 sets a ceiling of 62. A “â–³IIC” or impact-improvement number on a product datasheet is the improvement that one specific lab build-up showed relative to a reference slab; it is a contribution measured under particular conditions, not the compliance value for your building, and it cannot simply be added to a slab rating. Australian certifiers work from AS ISO 717.2 assembly data, which is why we provide third-party data and arrange build-up testing rather than printing a plank number.
Why do floors that pass in the lab fail on site?
The usual reason is flanking transmission — sound travelling around the separating floor through the building structure, wall junctions and service penetrations, rather than straight through the floor. A laboratory element test isolates the floor and does not capture these paths, so a build-up that performs in the lab can still fall short in-situ. This is why NCC compliance is best confirmed by in-situ testing or by an assembly designed with flanking control, and why detailing at junctions and services matters as much as the floor finish.
What acoustic evidence can Ecoflors provide for an Australian project?
Ecoflors can confirm the IXPE acoustic backing specification, provide third-party acoustic test data on request, and arrange testing of a specific floor build-up so your acoustic consultant has real figures to design and verify against. What we do not do is stamp an Ln,w or IIC number on a product and present it as an Australian compliance value — the compliance value belongs to the assembly and is verified by a NATA-accredited laboratory. This keeps your specification defensible at certification stage.
Factory-direct · IXPE acoustic backing · Third-party data on request · NATA testing arranged
Specify SPC for F7 with evidence, not marketing dB.
Tell us the project and the assembly your acoustic engineer is targeting. We confirm the IXPE backing specification, provide third-party acoustic data on request, and arrange testing of your build-up so your consultant has real AS ISO 717.2 figures to verify against — alongside FloorScore SCS-FS-05154 and AS 4586 slip data for the full specification.
Rigid-core SPC · 1mm IXPE acoustic backing · FloorScore SCS-FS-05154 · GREENGUARD Gold
FOB Ningbo / Shanghai · MOQ 800 sqm / SKU · factory-direct since 2017 · acoustic data on request
Disclaimer: General information for specifiers, developers and importers, not acoustic, building-certification or legal advice. NCC requirements are set by the Australian Building Codes Board and adopted by states and territories with variations; Part F7 figures (airborne Rw + Ctr ≥ 50 per AS/NZS ISO 717.1; impact Ln,w ≤ 62 per AS ISO 717.2; F7V1 in-situ DnT,w + Ctr ≥ 45 and LnT,w ≤ 62) should be confirmed against the current NCC and the project’s acoustic engineer. Sound insulation performance is a property of the complete floor-ceiling assembly including flanking paths, not the floor covering alone, and is verified by NATA-accredited testing — Ecoflors does not represent a product Ln,w or IIC figure as an Australian compliance value. Reviewed June 2026.
