Understanding “Reasonable and Necessary” in NDIS Home Modifications

When it comes to home modifications funded by the NDIS, one of the most important considerations is whether a proposed modification meets the criteria of being reasonable and necessary. This principle sits at the heart of all NDIS-funded supports — and it’s what determines whether a modification is approved.

But what does reasonable and necessary really mean when it comes to building works?

What Makes a Home Modification “Reasonable and Necessary”?

For a modification to be funded by the NDIS, it must:

• Directly relate to the participant’s disability – The modification must address functional limitations that result from a participant’s disability, rather than general home improvements.

• Represent value for money – The cost of the modification must be justified in relation to the long-term benefits it provides, and compared to alternative solutions.

• Support the participant’s goals – The modification should help the participant pursue goals outlined in their plan, such as greater independence, improved safety, or increased access to community activities.

• Be safe, compliant, and durable – All works must meet Australian Building Standards and NDIS Home Modifications Guidelines to ensure structural integrity and long-term use.

  
  

Why This Matters

The “reasonable and necessary” framework ensures that NDIS funding is used effectively — but it can also make the approval process more complex.

For Occupational Therapists, Support Coordinators, and participants, this means every submission must be backed by clear evidence, detailed reports, and realistic cost estimates that demonstrate the modification’s necessity, compliance, and value for money.

Our Role in Supporting the Process

At Complete Project Partners, we bridge the gap between clinical need and practical delivery.

Our team works with OTs and participants to ensure:

• All proposed modifications are technically sound and compliant

• Cost estimates align with market rates and NDIA expectations

• Documentation supports the “reasonable and necessary” criteria

• Projects progress smoothly from design and costing through to completion

  
  

By combining technical expertise with a strong understanding of NDIS processes, we help ensure modifications are not only approved — but also built to truly enhance quality of life and independence.

Because every modification should empower, not complicate, a participant’s journey toward greater independence and comfort at home.