SDA building types and NCC classification: Class 1a, 1b, 2 or 3? (NSW guide)

The NDIS SDA Rules Schedule 1 maps each SDA building type to a menu of NCC classes. The class your certifier assigns changes the access, fire and approval scope. The NDIA's SDA Report 2026 shows build type is also a demand decision. Sydney Access Consultants is an accredited SDA assessor (SDA00039). This is general information; the certifier decides the class.

Current NSW work is assessed against NCC 2022 Amendment 2 until NSW adopts NCC 2025 on 1 May 2027.

The short answer: SDA building types and their NCC classes

SDA building type	Key features (paraphrased from SDA Rules Schedule 1)	NCC class allowed
Apartment	In a multi-storey building	Class 2
Villa, duplex or townhouse	3 or fewer residents, separate accessible entry, no resident internal travel between dwellings	Class 1a or 3
House	3 or fewer residents; low-rise, separate land area	Class 1 or 3
Group home	4 or 5 long-term residents	Class 1b or 3

Confirm the exact wording in the current compilation of the NDIS (Specialist Disability Accommodation) Rules 2020 on legislation.gov.au.

How NSW certifiers decide the class

Class 1a: one dwelling, or attached dwellings separated by a fire-resisting wall.

Class 1b: boarding house, guest house, hostel or the like ordinarily accommodating no more than 12 people and no more than 300 m² total floor area. Some regulators do not accept Class 1b for residents needing special care. Confirm the NSW position.

Class 2: SDA apartments in a residential flat building.

Class 3: includes accommodation for people with disability and a residential care building (where 10% or more of residents need physical assistance with daily activities and to evacuate, per NCC Schedule 1). About 75% of new enrolled dwellings in the SDA Report 2026 were High Physical Support, which increases the chance of a Class 3 outcome.

Where classification is unclear, the approval authority has discretion (ABCB NCC Navigator). Raise it at pre-DA, not at CC.

What the class changes

Class 1a generally sits under Volume Two with no Part D4 access provisions (SDA Design Standard still applies). Class 1b, 2 and 3 bring Volume One, Part D4 and Premises Standards considerations for relevant areas. Fire safety (detection, separation, sprinklers by storeys) and NSW Design and Building Practitioners scheme obligations differ by class. Refer fire matters to the BCA and fire engineer. Confirm DBP Act regulated classes on the NSW Government page.

See SDA vs livable vs adaptable and livable housing. Sydney Access Consultants does not claim Livable Housing assessor registration.

SDA Design Standard on top of the NCC

The SDA Design Standard applies regardless of NCC class. Design categories: Improved Liveability, Fully Accessible, Robust, High Physical Support. Certification at design and as-built stages: see SDA certification. See also SDA design standard review.

Build type is now a demand question: what the SDA Report 2026 shows

From the NDIA Specialist Disability Accommodation Report 2026 (data to 31 December 2025, published 2026):

House (3 resident) was the most common build type in Home and Living decisions (about 45% of need).
Recent supply growth has concentrated in smaller dwelling types, including 2-resident houses, creating a risk that participant demand and available SDA supply are not aligned on build type.
NSW had 8,124 participants with an SDA need (5,112 in use).

No occupancy, rent or return claims. Check local demand.

Feasibility checklist for NSW SDA projects

Building type versus local demand.
Resident count.
Class the certifier is likely to assign.
Residential care building risk.
OOA/OSS location if applicable.
Fire separation between villas.
Separate accessible entries.
Site and land-title features (house "separate land area" test).
Design category per dwelling.
Provisional certification timing.

How Sydney Access Consultants helps

Early classification and access advice, SDA design review, provisional and as-built certification (accredited SDA assessor SDA00039). Coordination with the certifier, BCA and fire consultants. Call (02) 9586 3111. Work is based in Hurstville. On the Mid North Coast, Sandy Grey works from Black Beach.