NCC 2025 Volume One — What's Changed (v2)
National Construction Code 2025 Preview Draft vs NCC 2022 Deep Research Report — March 2026
Overview
The NCC 2025 Volume One (Building Code of Australia — Class 2 to 9 buildings) introduces significant new provisions and updates across fire safety, water management, energy efficiency, accessibility, sanitary facilities, and electric vehicle infrastructure. The preview draft was released in February 2026, with earliest adoption expected from May 2026 (jurisdiction-dependent).
This report covers three areas:
- What's NEW — provisions that did not exist in NCC 2022
- What's UPDATED — existing provisions that have been revised
- Why — the drivers and rationale behind the changes
1. What's NEW in NCC 2025
1.1 EV Charging Infrastructure (Section J / Part J9)
EV charging provisions were first introduced in NCC 2022 Amendment 2 (effective October 2023) for Class 2 buildings. NCC 2025 extends and refines these requirements across commercial building classes.
Important clarification: Class 2 (apartments) EV-ready requirements are not new in NCC 2025 — they were established under NCC 2022 Amendment 2. Building Ministers have paused further residential changes until mid-2029. NCC 2025's EV changes primarily affect commercial classes.
Requirements by building class:
| Building Class | Description | NCC 2022 | NCC 2025 |
|---|---|---|---|
| Class 2 | Apartments | 100% EV-ready (NCC 2022 Amd 2) | Unchanged — paused until 2029 |
| Class 3 | Hotels, motels | Limited | Charging infrastructure for guest parking |
| Class 5 | Offices | Limited | Conduit pathways + electrical capacity |
| Class 6 | Retail/shops | ~5% | 10% of carpark spaces with dedicated EDBs |
| Class 7a | Carparks (stand-alone) | Not required | Exempt |
| Class 7a | Carparks (within other buildings) | Not required | Follows associated building class |
| Class 8 | Factories/labs | Limited | Provisions proportional to vehicle demand |
| Class 9 | Public buildings | Limited | Charging provisions for staff/visitor parking |
Class 2 EV-ready technical specs (NCC 2022 Amd 2, continuing unchanged):
- 100% of car spaces must be EV-ready (infrastructure, not chargers)
- Dedicated EV distribution board separate from building systems
- Circuits supporting minimum 7 kW (32A) single-phase Type 2 chargers
- Minimum 12 kWh delivery between 11pm–7am daily
- Active conductors: minimum 6mm² cross-sectional area
- Max 50m cable run from distribution board to EVSE outlet
- 36mm DIN rail space per circuit for future metering
- One additional distribution board per 24 car spaces beyond 168 per storey
- Mandatory charging control system (load management)
- Compliance via DtS (Part J9D4) or Performance Solution (Clause A2G2)
Class 6 EV charging technical specs (NEW in NCC 2025):
- 10% of carpark spaces must have EV charging equipment
- Dedicated electrical distribution boards (EDBs) per storey, labelled for EV use
- Load management/charging control system required
- Separate sub-circuit metering for each EV charging device
- EDBs located no more than 10m from busduct (where busduct solution used)
1.2 Mandatory On-Site Solar (Section J — New DtS for Class 3–9)
NCC 2025 introduces a new DtS requirement for mandatory on-site photovoltaic (PV) systems on commercial buildings.
- Class 6 buildings: Solar panels required on 100% of available roof space
- Exclusions: trafficable zones, plant spaces, shaded areas
- Class 7a buildings: Exempt from solar panel requirements
- Supports the "near zero operational greenhouse gas emissions" performance requirement
1.3 Water Management Framework (Part F1 — Restructured/New)
NCC 2025 consolidates and expands water management into a unified framework under Part F1. This replaces the fragmented approach in NCC 2022 where waterproofing, weatherproofing, and water shedding were treated somewhat separately. Parts F1 and F3 have been merged into a single Part F1.
New framework structure:
Notable new/strengthened requirements:
- Minimum 1:80 gradient for water shedding on balconies, podiums, and accessible areas
- 70mm step-downs at door thresholds to external tiled areas
- Expanded scope to cover previously unregulated junctions and interfaces
- Performance-based pathways with clearer verification methods
- Class 7 and 8 buildings now included — previous waterproofing exemptions removed
1.4 All-Gender Sanitary Facilities (Part F4 — New Provision)
NCC 2025 formally introduces provisions for all-gender (unisex) sanitary facilities in certain building types, reflecting contemporary approaches to inclusive design.
- Applicable to new Class 5, 6, and 9 buildings above certain thresholds
- Provisions allow all-gender facilities to count toward overall sanitary fixture requirements
- Privacy and safety design requirements included (full-height partitions, individual lockable compartments)
2. What's UPDATED in NCC 2025
2.1 Fire Safety — Carpark Sprinklers & FRL (Section C)
This is the most significant fire safety change in NCC 2025, driven by an Arup literature review of ~400 sources commissioned by ABCB.
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Sprinklers (>40 spaces, enclosed) | Required | Required (unchanged) |
| Sprinklers (>40 spaces, open-deck) | Exempt | Now mandatory |
| Sprinklers (stand-alone open-deck) | Exempt | Still exempt |
| Car stackers | No sprinkler requirement | Mandatory sprinklers |
| FRL — open-deck Type A/B | 60/60/60 | 120/120/120 |
| FRL concessions (sprinkler-protected) | Available for Type A below other classes | Removed |
| EV fire risk | Not addressed | Acknowledged (toxic fumes, thermal runaway, re-ignition risk) |
Key details on EV fire considerations:
- EV battery fires produce significantly more smoke and toxic gases (including hydrogen fluoride) than conventional vehicles
- Require hours or days of firewater cooling for control
- Risk of re-ignition hours/days after initial extinguishment
- ABCB determined EVs should not be classified as "special hazards" — they are now common
- Queensland Fire's request to classify EVs under special hazard provisions (E1D17/E2D21) was not adopted
Rationale: The 1980s research underpinning the old open-deck exemptions did not account for modern vehicles (larger, more plastic content, EV batteries). The Arup review confirmed the updated risk profile.
2.2 Waterproofing & Water Shedding (Part F1)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Balcony gradients | General guidance, no minimum | 1:80 minimum gradient mandated |
| Door step-downs | Varied/unclear | 70mm step-down at doors to external tiled areas |
| Scope | Primarily internal wet areas | Extended to balconies, podiums, terraces, external junctions |
| Class 7 & 8 buildings | Exempt from waterproofing | Now included under F1P2 |
| Wall cladding (Zones 6-8) | Direct-fix permitted | Drained/ventilated cavity (min 18mm) required |
| Verification methods | Limited | Expanded performance-based pathways |
2.3 Condensation Management (Part F8)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Vapour permeance | General requirements | Class 4 vapour permeance classification for barriers |
| Climate zones | Zones 6-8 for roof ventilation | Extended to Climate Zones 4-8 |
| Ventilation | Basic requirements | Enhanced mechanical/passive ventilation; mandatory vapour-permeable membranes |
| Roof spaces | General guidance | Specific condensation control + moisture escape pathways |
| Small roofs | Standard requirements | Reduced ventilation requirements |
2.4 Women's Toilet Ratios (Part F4)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| General ratio (F:M) | 1:1.25 | Maintained at 1:1.25 for most building types |
| Theatres & cinemas | 1:1.25 | Increased to 1:1.8 (F:M) |
| Assembly buildings | 1:1.25 | Increased ratios for high-attendance venues |
Rationale: Evidence-based adjustment to reduce queue times at high-turnover venues.
2.5 Energy Efficiency (Section J)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Performance target | Energy efficiency | Near zero operational greenhouse gas emissions |
| Solar panels (Class 6) | Not mandatory | Mandatory — 100% available roof space |
| Solar panels (Class 7a) | N/A | Exempt |
| Facade solar admittance | Baseline | ~44% tighter wall-glazing solar admittance |
| Glazing | Prescriptive SHGC/U-value | Updated values for current glazing tech |
| HVAC | Efficiency baselines | Raised minimum efficiency |
| Reporting | JV3 verification | Enhanced NatHERS and JV3 alignment |
Rationale: Aligned with Australia's net zero 2050 target. Buildings account for ~25% of national energy consumption.
2.6 Structural Provisions (Section B)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Performance-based assessment | General framework | Enhanced documentation and verification |
| Referenced standards | AS/NZS 1170 (2021) | Updated to latest published editions |
| Robustness | Implicit | More explicit progressive collapse and structural robustness provisions |
| Means of assessment | General | Amendments to A2G2, B1P1, H1P1 for consistent Performance Solutions |
2.7 Accessibility (Part D — AS 1428.1 Update)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Referenced standard | AS 1428.1-2009 | Updated to AS 1428.1:2021 |
| Luminance contrast | General requirements | Strengthened minimum ratios |
| Tactile indicators | Basic provisions | Updated installation and spacing |
| Accessible toilets | AS 1428.1-2009 layout | Revised layout per 2021 standard |
| Class 6 adult change facilities | Basic | Required in shopping centres above thresholds |
| Class 7a accessible parking | Basic | Minimum 1 space per AS/NZS 2890.6; signage for carparks >5 spaces |
2.8 Carpark Ventilation (Class 7a)
| Aspect | NCC 2022 | NCC 2025 |
|---|---|---|
| Base ventilation rate | Higher baseline (single engine) | Halved — reduces size, cost, energy, materials |
| CO exposure limits | Table-based | Updated Table FV4.2 limits |
| Open-deck definition | Cross-ventilation 2 sides | Unchanged — 1/6 area ratio, 1/2 wall area openings |
| EV contaminants | Not addressed | Note: AS 1668.2 does not cover EV battery charging contaminants — designers must investigate |
3. Class-Specific Change Summary
Class 7a — Carparks
Class 6 — Retail / Shops / Cafes
4. Reasons Behind the Changes
4.1 Summary of Drivers
4.2 Detailed Rationale
Building Defect Prevention
Water ingress and waterproofing failure remain the number one category of building defects in Australia. The consolidated water management framework directly targets this by mandating measurable gradients (1:80), specifying step-down dimensions (70mm), and expanding scope to balconies and terraces. The removal of Class 7/8 waterproofing exemptions acknowledges that carparks also suffer from water management issues.
Condensation and mould issues have increased as buildings become more airtight for energy efficiency. Extended Climate Zone 4-8 coverage and Class 4 vapour permeance requirements address these unintended consequences. Wall cladding changes (drained cavities in Zones 6-8) prevent moisture trapping behind facades.
Safety Modernisation
The Arup literature review (~400 sources) confirmed that 1980s carpark fire research is obsolete. Modern vehicles are larger, contain more plastics, and include EV batteries that burn differently. The FRL increase from 60/60/60 to 120/120/120 for open-deck carparks and mandatory sprinklers for >40 spaces directly respond to this evidence.
Environmental & Climate Policy
Australia's net zero 2050 commitment requires the building sector (~25% of national energy) to improve significantly. Mandatory solar panels for Class 6, tighter facade thermal performance (~44% reduction in solar admittance), and enhanced HVAC efficiency standards all contribute. The "near zero operational greenhouse gas emissions" performance requirement replaces the previous energy efficiency framing.
Social Equity & Inclusivity
Updated women's toilet ratios for theatres/cinemas (1:1.8) are evidence-based. All-gender sanitary facilities reflect inclusive design principles. Updated accessibility standards (AS 1428.1:2021) incorporate a decade of research since the 2009 edition.
5. Implementation Timeline
Key dates:
- February 2026: Preview draft published
- May 2026: Earliest jurisdiction adoption (ACT confirmed with 6-month transition)
- October 2025: Building Ministers agreed to pause residential changes until mid-2029
- Tasmania: Committed to freezing (not adopting) NCC 2025 EV changes
- NSW, VIC, QLD, SA, WA: Adoption dates not yet confirmed
Sources
Official
- ABCB — NCC 2025 Preview
- ABCB — Carpark Fire Safety Improvements
- ABCB — Arup Fire Safety in Carparks Literature Review
- ABCB — Waterproofing Provisions
- ABCB — J9D4 EV Charging Facilities Guide
- DCCEEW — NCC 2025 EV Charging Guidance
- DCCEEW — NCC 2025 Mandatory Onsite PV
- DCCEEW — NCC 2025 Envelope Guidance
Industry
- MBA NSW — NCC 2025 Key Changes
- MBA ACT — NCC Changes 2025
- HIA — NCC 2025 Analysis
- HIA — External Waterproofing Changes
- HIA — Roof Ventilation Condensation Changes
- MBC Group — NCC 2025 vs NCC 2022 Comparison
- Engineers Australia — NCC 2025 Submission
- Electric Vehicle Council — NCC 2025 Response
Technical
- Bright Connect — NCC EV Charging in Carparks
- EVSE Australia — Class 2 EV Requirements
- Sotera Fire Engineering — NCC 2025 Fire Safety
- Palantir Consulting — 5 Critical NCC 2025 Changes
- Queensland Fire — EVs and Charging in Carparks
Report generated March 2026. Based on the NCC 2025 Preview Draft — final adopted version may differ.