SDA design FAQs: A Guide for developers

Specialist Disability Accommodation (SDA) FAQs: A Practical Design Guide for Developers

Planning an SDA development but unsure what can be built, which design category applies, or what your architect needs to consider?

Specialist Disability Accommodation, commonly called SDA, is housing for people with extreme functional impairment or very high support needs. SDA incorporates features intended to help residents live more independently while enabling other supports to be delivered more effectively and safely. [ndis.gov.au]

For developers, however, getting an SDA project right involves more than simply providing an accessible bathroom or wider doors.

The building type, SDA design category, site planning, circulation, dwelling configuration, certification and eventual enrolment pathway need to work together.

This Q&A explains the fundamentals from an architectural and property-development perspective.

What types of buildings can be used for SDA?

Under current NDIS guidance, an SDA home can fall into four building types:

1. Apartments

An apartment forms part of a larger residential building while providing an individual dwelling for the resident.

2. Villas, duplexes and townhouses

For residential developers, this category creates possibilities for lower-scale developments where individual dwellings are grouped or attached.

3. Houses

A house can accommodate up to three people under the current SDA building-type guidance. 

4. Group homes

A group home accommodates four or five people. 

Developer Tip:Do not choose an SDA building type solely because it appears to maximise the number of dwellings on a site. The dwelling configuration, SDA category, participant needs, planning controls, access, parking, private open space and certification requirements need to be considered together.

What are the SDA design categories?

The current SDA Design Standard has four design categories:

• Improved Liveability

• Fully Accessible

• Robust

• High Physical Support 

Each addresses a different set of participant needs.

What is Improved Liveability SDA?

Improved Liveability is intended to improve usability for people who may have sensory, intellectual or cognitive impairment.

From a design perspective, considerations can extend beyond physical accessibility to matters such as:

• intuitive circulation

• visibility and sightlines

• easy-to-understand spatial organisation

• visual contrast

• wayfinding

• legibility of entrances and important spaces

The objective is not simply to create a dwelling someone can enter.

It is to create a home that is easier to understand, navigate and live in.

What is Fully Accessible SDA?

Fully Accessible addresses residents with significant physical impairment and requires a high level of physical accessibility. The category is one of the four categories recognised by the current SDA Design Standard. 

For architects and developers, early design thinking should therefore address issues such as wheelchair circulation, entry and internal movement, usable bathrooms, kitchens, private outdoor space and dwelling layouts.

This is why accessibility should ideally influence the floor plan from the beginning rather than being added after a conventional dwelling has already been designed.

What is Robust SDA?

Robust SDA combines accessibility with a dwelling environment designed for resilience.

The architectural response may need to carefully consider:

• durable finishes

• impact-resistant construction

• fixtures and fittings

• doors and windows

• acoustics

• safety

• opportunities for retreat

• spatial planning appropriate to occupants' needs

The goal is not to make a home feel institutional.

Good robust design should balance durability, safety and residential character.

Robust is one of the four current SDA Design Standard categories.

What is High Physical Support SDA?

High Physical Support (HPS) addresses participants who have significant physical impairment and very high support needs.

The architectural brief can therefore be significantly more sophisticated than ordinary accessible housing.

Your supplied material highlights design considerations such as wheelchair accessibility, allowance for ceiling hoists, assistive technology, emergency power and appropriate environmental controls. These requirements should be checked against the applicable current SDA Design Standard for the particular project rather than relying on an abbreviated checklist.

High Physical Support is one of the four categories under the current SDA Design Standard. 

Are Basic, Silver, Gold and Platinum still SDA design categories?

This is an important distinction.

Current NDIS guidance identifies Improved Liveability, Fully Accessible, Robust and High Physical Support as the four SDA Design Standard categories. [ndis.gov.au]

Older SDA material and accessibility references can contain terminology such as:

• Basic

• Silver

• Gold

• Platinum

These should not be presented as the four current SDA Design Standard categories.

This distinction is particularly important for developer websites because mixing historic Livable Housing terminology with current SDA categories can make an otherwise useful technical article misleading.

What should an architect consider when designing SDA?

An SDA architect needs to consider the whole journey through the dwelling, not individual dimensions in isolation.

Key design topics include:

Arrival

Can a participant safely and conveniently move from the street or accessible parking area to the dwelling?

Entrance

Is the entrance accessible, sheltered where required and designed with sufficient circulation space?

Internal circulation

Do doors, corridors, corners and room layouts provide appropriate movement and manoeuvring space?

Bathrooms

Can bathrooms achieve the applicable accessibility, circulation, shower, WC, reinforcement and fixture requirements?

Kitchens

Does the kitchen accommodate the particular SDA category and resident needs instead of merely satisfying standard residential planning conventions?

Bedrooms

Is there appropriate circulation around the bed and sufficient room for equipment or assistance where required?

Living spaces

Can a wheelchair user comfortably enter, turn, position themselves and move through the principal living areas?

Technology

Where required, has the dwelling been designed to accommodate assistive technology rather than attempting to retrofit it after construction?

Structure

If ceiling-hoist capability or other specialist equipment is required, has this been considered structurally before construction?

External areas

Can residents actually access and use the private outdoor areas provided?

These questions demonstrate why a successful SDA project starts with spatial planning, not simply a checklist of accessible products.

What dimensions should developers use for SDA?

This is where caution is particularly important.

Your source material contains numerous dimensions associated with older Silver, Gold and Platinum frameworks, including path widths, door clearances, parking dimensions, bathroom circulation areas, shower sizes, kitchen clearances and bedroom circulation.

For a new SDA development, those dimensions should not be copied wholesale into a design brief and assumed to satisfy current SDA requirements.

The official SDA Design Standard provides detailed design requirements and is intended to give architects, builders and the wider community information about specialist housing design. 

A better architectural workflow is:

Site feasibility → Building type → SDA category → Concept planning → Detailed SDA compliance review → SDA design-stage assessment → Documentation → Construction → Final as-built certification → Enrolment

The NDIS confirms there are two stages of SDA Design Standard certification, at design stage before construction and at final as-built stage.

That makes early compliance assessment extremely valuable.

Does SDA certification guarantee that a dwelling will be enrolled?

No.

This is an important distinction for developers and investors.

The NDIS states that SDA Design Standard certification does not itself mean a dwelling will be enrolled as SDA. The NDIA determines whether the home can be enrolled after receiving the completed application and after construction is complete. 

This distinction should be understood before treating an SDA development purely as a yield or investment exercise.

When can a developer apply to enrol a home as SDA?

Current NDIS guidance says an application to enrol a home as SDA can only be made once the dwelling is built and complete.

For this purpose, completion occurs when a certificate of occupancy, completion or equivalent has been issued.

For new builds, the enrolment documentation includes items such as:

• proof of ownership

• permission to enrol when the owner and SDA provider differ

• certificate of occupancy or equivalent

• applicable certification documentation

• SDA Design Standard final-as-built certification.

SDA providers must also be registered with the NDIS Commission and have the appropriate SDA registration group approved. 

Why should SDA be considered at the feasibility stage?

For a property developer, the biggest design mistake may be starting with a conventional townhouse or apartment layout and trying to make it SDA-compliant later.

SDA requirements can influence:

site layout → parking → accessible paths → entrances → dwelling width → circulation → bathrooms → kitchens → bedrooms → structure → services → assistive technology → outdoor areas

Those requirements can ultimately affect the efficiency of the entire development.

An architect familiar with both property development and SDA design can therefore test accessibility alongside the issues developers already care about:

• site constraints

• dwelling yield

• planning controls

• orientation

• access

• parking

• constructability

• building form

• resident amenity

The result should be a development that works commercially, architecturally and for the people who will ultimately call it home.

SDA Design FAQ for Property Developers

Can a duplex be SDA?

Yes. Current NDIS guidance includes villas, duplexes and townhouses as an SDA building type. 

Can an apartment be SDA?

Yes. Apartments are an identified SDA building type. 

Can a detached house become SDA?

A house is one of the current SDA building types and can accommodate up to three people under the NDIS building-type guidance. 

What are the four SDA design categories?

They are Improved Liveability, Fully Accessible, Robust and High Physical Support. 

Does an SDA dwelling need certification?

For SDA Design Standard certification, the NDIS identifies two certification stages: design stage and final as-built stage, with certification signed by an SDA assessor.

Does certification automatically guarantee SDA enrolment?

No. The NDIS expressly states that SDA Design Standard certification does not guarantee enrolment.

Is the SDA Design Standard changing?

The NDIA is currently reviewing the SDA Design Standard. The consultation ran between October and December 2025, and a Technical Working Group has been established to support development of the next edition. 

Designing an SDA Development in Victoria?

At AU Architecture, we approach SDA as both an accessible-housing challenge and a property-development problem.

The strongest projects begin before the floor plans are locked in.

By considering site potential, planning controls, dwelling configuration, accessibility and the intended SDA category together, developers can identify constraints much earlier and create housing that is functional, considered and genuinely centred around residents.

Considering an SDA site?

Start with feasibility before committing to a dwelling layout.

Understanding what the site can realistically accommodate can help establish the right building type, development strategy and SDA design direction before detailed documentation begins.

AU ArchitectureArchitecture + Property Development + Accessible Housing: Designing better housing from feasibility through to built outcome.