Specialist Disability Accommodation, or SDA, is housing designed for people with very high or complex support needs. An SDA assessment is the occupational therapy housing assessment that sits at the centre of an SDA application. This guide explains what it is, the design categories, who is generally eligible, and how the assessment works.
A note on eligibility and funding: SDA is for a small group of participants with the highest needs, and funding is never automatic. It depends on your situation and a “reasonable and necessary” decision by the NDIS. Your support coordinator or planner can advise on your individual circumstances.
What is an SDA assessment?
SDA stands for Specialist Disability Accommodation. It is housing with special design features for people who need them, not the day-to-day support inside the home (that is Supported Independent Living, or SIL).
An SDA housing assessment is an occupational therapy assessment that documents a person’s functional capacity, the housing-related risks they face, and why standard housing, even with modifications, cannot meet their needs. This report is the cornerstone of an SDA application, and a strong one is essential.
The four SDA design categories
SDA homes are built to one of four design categories, matched to a person’s needs:
- Improved Liveability – for people with sensory, cognitive or intellectual needs.
- Fully Accessible – for people with significant physical impairment, including wheelchair access.
- Robust – resilient design for people with complex behaviours who need a durable, safe environment.
- High Physical Support – for people with very high physical and clinical needs, with features such as ceiling hoists and home automation.
Who is generally eligible for SDA?
SDA is intended for participants with extreme functional impairment or very high support needs that require specialist housing design which standard housing cannot provide, even with modifications. Because it is for a small group with the highest needs, the evidence bar is high, which is why the OT assessment matters so much.
What the SDA assessment involves
An SDA housing assessment is detailed and typically takes many hours across one or more visits. It documents:
- your current functional capacity across daily activities,
- the specific housing risks and barriers you face now, and
- why standard housing, even with home modifications, is not enough to meet your needs.
SDA assessments can only be completed by accredited assessors, which may include occupational therapists, architects, access consultants and building surveyors who meet specific requirements.
SDA and SIL work together
SDA is about the home; SIL is about the support delivered inside it. Many participants need both, assessed separately. For the difference and which report the NDIS needs, see SIL vs SDA: what OT report does the NDIS need? and our guide to SIL assessments. Where standard housing can be made suitable with changes instead, our guide to home modifications may be relevant.
Frequently asked questions
What is an SDA assessment?
It is an occupational therapy housing assessment that documents why a person needs specialist disability accommodation, and which design category suits their needs. It is the central piece of evidence in an SDA application.
What are the four SDA design categories?
Improved Liveability, Fully Accessible, Robust, and High Physical Support. The right category depends on a person’s functional and clinical needs.
Who is eligible for SDA?
SDA is for participants with extreme functional impairment or very high support needs that standard housing cannot meet, even with modifications. Funding is decided case by case.
What is the difference between SIL and SDA?
SDA is the specialist housing itself; SIL is the daily support delivered in the home. They are assessed and funded separately, and many people need both.
Sources
- NDIS, What is specialist disability accommodation and SDA design standards, ndis.gov.au.
- Provider guidance on SDA eligibility and OT housing assessments, accessed 18 July 2026.
SDA assessments follow the same method as every report we write. Read our full assessment methodology, including the evidence standard every recommendation is written to.