Reasonable and Necessary: How the NDIS Decides Your Housing
Reasonable and necessary housing explained: the criteria the NDIS uses to decide SIL, SDA and home and living funding, and how to meet them.
Every support in your NDIS plan has to pass one test: is it reasonable and necessary? For housing, that test decides whether you get SIL, SDA or other home and living funding — and it's often where requests succeed or stall. This guide explains what reasonable and necessary means for housing, the criteria behind it, and how to show your needs meet the mark.
What 'reasonable and necessary' means
The criteria behind the test
How it applies to housing specifically
Why goals are central
The role of informal and mainstream supports
Showing your housing need meets the test
If the answer is no
Frequently asked questions
What does reasonable and necessary mean for housing?
It's the legal standard every NDIS support must meet. For housing, it means the support is genuinely needed because of your disability, tied to your goals, good value, likely to work, and appropriately the NDIS's role rather than the health or housing system's. It's assessed against your individual…
Why does the NDIS consider my family's support?
The reasonable and necessary test takes into account what informal, community and mainstream supports reasonably provide. The NDIS funds the disability-related gap — support that wouldn't otherwise exist. It's not about withdrawing help, but about clearly showing which needs aren't already met by…
How do I show my housing need is reasonable and necessary?
Combine strong allied health evidence (an OT home and living assessment) with a clear home and living goal in your plan, a described arrangement explaining why alternatives fall short, and honest context about your informal support. This frames your genuine need in the terms the decision is actually…
What if the NDIS says my housing isn't reasonable and necessary?
It isn't always final. Often the issue is evidence or framing rather than the need itself. You can request a review of the decision. Strengthening your allied health evidence and linking the support clearly to a plan goal beforehand gives a review the best chance of success.