If you’re reading this, something at home has probably stopped working the way it needs to. A shower that isn’t safe to get into anymore. A back step that has quietly become a barrier. A doorway that a wheelchair doesn’t quite clear.
The NDIS sorts changes to a home into two groups, minor and complex. Those words describe the building work and the paperwork behind it. They are not a judgement about how much the change matters to the person living there. A set of lever door handles can change someone’s day as much as a lift does.
Here’s what separates the two, and what each one actually asks of you.
What is the difference between minor and complex NDIS home modifications?
Minor NDIS home modifications are straightforward changes that don’t affect the structure of the home, carry relatively low risk, and generally cost less than $25,000 in total. Complex home modifications affect the structure or need more custom and technical work, carry higher risk, often touch several areas of the home, generally cost more than $25,000, and need approvals and certificates of completion.
Examples help. The NDIA lists adding or removing taps, simple ramps, non-slip floor treatments and lever door handles as minor. Permanent ramps that need a building permit, lifts, and extensive electrical, plumbing or structural work sit on the complex side.
The dollar figure is the shorthand, not the test.
This is the part most people get caught on. The $25,000 line gets quoted everywhere as though it’s a switch, and it isn’t. Notice that the NDIA says generally.
What actually drives the classification is whether the work touches the structure of the home, how much risk it carries, and how many areas it affects. A modest-looking bathroom job that involves moving a load-bearing wall is structural regardless of its price. A larger run of non-structural work might still sit on the minor side.
If you’re unsure which side a job falls on, the useful question isn’t “what will this cost?” It’s “does this touch the bones of the house?”
| Minor | Complex | |
| Structure | Not affected | Affected, or needs custom technical work |
| Risk | Relatively low | Higher |
| Scope | Usually contained | Often several areas of the home |
| Cost (guide only) | Generally under $25,000 | Generally over $25,000 |
| Approvals | Usually none | Approvals and certificates of completion |
| Builder quotes | Usually not needed upfront | Two itemised quotes or cost estimates |
What a minor modification needs
A home modification assessor, usually an occupational therapist, assesses what’s needed and makes recommendations. Alongside that assessment, the NDIA wants supporting documentation such as floor plans, photographs and drawings.
What often surprises people is that a builder’s quote usually isn’t required. For minor modifications, the NDIA works from a set budget based on current market costs and where you live. Two situations change that: if you live in a remote or very remote area, or if the work costs more than what’s been funded. In the second case, you’d be asked for itemised quotes from two different builders.
What a complex modification needs
More moving parts, and more people in the room.
Alongside the assessor’s work, a building construction practitioner (BCP) reviews the proposed modifications and advises on how the home can actually be modified. The NDIA funds that role on complex jobs. They also help give builders the information needed to quote properly.
The evidence list for complex modifications runs longer: the assessment, the practitioner’s review, floor plans and photographs, two cost estimates or itemised quotes from builders, quotes from engineers or architects where relevant, and quotes for temporary facilities where relevant.
That last line deserves attention. If the only bathroom in the house will be out of action for three weeks, temporary facilities are a legitimate part of the conversation. Raise it early with your assessor rather than once the trades are on site.
On modifications that are very expensive and involve major structural work, the NDIA also funds a building works project manager. There’s a condition attached: that person must be independent of any builder quoting for the work. This is worth knowing before you ask one company to both quote and manage.
Why a one-line quote gets sent back
Builders’ quotes for complex modifications have a required shape, and a single total with a letterhead won’t cut it. A quote needs to show the dimensions of the area being modified, a separate costing for each stage of the job such as demolition, plumbing and electrical, a description of any fixtures supplied by the builder including make, model and cost, and an overall figure inclusive of GST where applicable.
That level of detail isn’t bureaucracy for its own sake. It lets the NDIA see which parts of the job are disability-related and which parts are ordinary home improvement, which is the line the whole decision turns on.
What the NDIS generally doesn’t fund
Funding is aimed squarely at the changes that help someone get into, move around and use their own home. The ramp, the widened doorway, the shower you can actually use, and the alteration that lets a support worker do their job safely. When a scope stays close to that purpose, it tends to move through assessment with far less friction.
A handful of things sit outside that focus, and they’re much easier to plan around once you can see them in one place:
- Standard furniture, fixtures and fittings, including cosmetic finishes like tiles or tapware that aren’t part of the modification itself.
- Swimming pools and spas, including those intended for hydrotherapy.
- Changes that make the home bigger, such as adding another storey.
- Repairs to pre-existing damage outside the immediate area being modified.
- Insurance premiums for the home once it has been modified.
- Routine repairs and maintenance that an owner or landlord would normally take care of.
- Rework on modifications that didn’t follow Australian Standards.
None of this closes a door. It simply means a scope works best when the disability-related changes are kept clearly separate from general home improvement, which is the same reason quotes are asked to be itemised stage by stage. Plenty of people choose to do a little extra work while the trades are already on site, and funding the two parts differently is a perfectly normal way to handle it.
That last point on the list is the most useful one to act on early. Choosing licensed trades from the outset keeps the work inside what the scheme supports: licensed builders for carpentry and building work, licensed plumbers for bathroom and plumbing changes, and licensed electricians for any electrical work.
Whose house is it, and who has to agree
NDIS funding can pay for modifications to a home someone owns, or to a home where the owner agrees to the changes. Written consent from the property’s legal owner or their representative is part of the evidence. Where ownership is shared, permission comes from the responsible body, such as a body corporate.
If you’re renting, start that conversation earlier than feels necessary. Landlord consent and body corporate approval both run on their own timelines, and they are the most common reason a well-prepared file sits still.
Where projects tend to get stuck
Four patterns come up repeatedly, and all four are avoidable.
- Waiting until funding lands before speaking to a builder, which means the quote work starts from zero at the worst possible moment.
- Quotes that are too vague to be assessed.
- An assessor and a builder who never speak to each other, so the recommendation and the buildable solution drift apart.
- Nobody thinking through where the person will shower, cook or sleep while the work happens.
Talk it through before the drawings are locked in.
You don’t need the whole picture before you take a first step. Ask your assessor which side of the line they think the work sits on and why, and start the owner consent conversation in parallel.
When you’re ready for the building side of it, we’d be glad to help. Mathiou Services is a registered NDIS provider and a licensed builder, working across Queensland and Northern NSW. We’re often brought into NDIS home modifications early enough to speak directly with an assessor or occupational therapist, which usually makes for a scope that’s buildable and a quote itemised the way the NDIA asks for.
We also work on changes in supported and independent living homes, where the result has to suit both the person living there and the people supporting them.
If you’d like to walk through what you’re considering, get in touch or call 1300 363 423. There’s no obligation and nothing to decide on the spot. A short conversation early on is often enough to tell you what’s worth raising in your assessment.