A wheelchair friendly threshold is either a flush, level entry or a ramped threshold that meets AS 1428.1: a maximum 1:8 gradient, a maximum 35 mm rise, and a maximum 280 mm length. Flush entry is the goal wherever drainage and weatherproofing allow it. Where a lip already exists, a rubber wedge ramp fixes it fast and without tools, while an aluminium or integrated drainage threshold suits a permanent, weatherproof upgrade.
TL;DR:
- Rubber wedge ramps are suitable for lips under approximately 40 mm and are easy to install without tools, making them ideal for temporary or testing purposes.
- Fixed aluminium thresholds and integrated drainage channels provide more durable, weatherproof solutions, but require careful measurement, proper installation, and possibly involving a builder or certifier.
- Complying with AS 1428.1 standards means ensuring the ramp gradient does not exceed 1:8, the rise stays within 35 mm, and the length remains under 280 mm for safety and accessibility.
- For external doors, an 820 mm minimum clear opening is recommended, but door frame depth and flooring transitions may influence the feasible threshold solution.
- Cost and timeline vary widely; rubber ramps are the cheapest and fastest, while integrated flush thresholds with drainage are at the top and take longer to install and cost more.
Table of Contents
- What qualifies as a wheelchair friendly threshold?
- Which Australian standards set the threshold rules?
- Rubber ramps, aluminium ramps, or a flush threshold: which one fits?
- How do you measure and calculate the right ramp gradient?
- Should you install it yourself or call a professional?
- Why installers push for flush entry over ramps
- How does NDIS funding work for threshold upgrades?
- What does a wheelchair friendly threshold cost to install?
- How long does it take to buy and install a threshold ramp?
- What are the common mistakes when choosing a threshold solution?
- Does the threshold solution depend on your door type or flooring?
- Our take: standards first, product second
- Get a compliant, custom-fitted door and threshold sorted properly
- Sources
- FAQ
What qualifies as a wheelchair friendly threshold?
Three forms count as accessible. The first, and the one every accessibility standard treats as best practice, is a flush or level entry: no step, no lip, no transition to navigate at all. The second is a rounded or bevelled sill, which is acceptable when the height difference sits at 5 mm or less, since a wheel can roll over that without catching.
The third is a ramped threshold, used when the door frame or slab sits higher than the surrounding surface and a full flush rebuild isn’t practical. You’ll see these most often on external doors with sliding tracks, older weatherboard homes with raised frames, or renovated bathrooms where a shower hob has been lowered but not eliminated. A ramped threshold has to earn its place; it is a compromise solution, not a design choice, and the gradient and length limits below exist precisely because a poorly pitched ramp is more dangerous than the step it replaces.
Which Australian standards set the threshold rules?
Two documents do the heavy lifting here, and tradies and specifiers both work from the same numbers.
AS 1428.1 governs threshold ramps on any continuous path of travel. The requirements are specific:
- Maximum gradient of 1:8 (roughly one unit of rise for every eight units of run)
- Maximum rise of 35 mm
- Maximum length of 280 mm
- Positioned within 20 mm of the door leaf
- Tapered or splayed edges wherever the ramp doesn’t run into a wall, so there’s no sharp lip to catch a caster wheel
A threshold ramp that exceeds 35 mm rise or a 1:8 gradient no longer meets AS 1428.1, regardless of how the product is marketed.
The Livable Housing Design Standard, folded into the NCC in 2022, sits alongside it. It prefers level entry outright, and where a ramp is used instead, that ramp can’t be steeper than 1:8 and must be at least as wide as the door’s clear opening. Specified doorways also need an 820 mm minimum clear opening, measured from the door stop to the face of the fully open leaf.
These two standards occasionally pull in different directions. A flush entry that satisfies accessibility can conflict with water-penetration rules under AS 2047, which is where a certifier or performance solution earns its fee.
Rubber ramps, aluminium ramps, or a flush threshold: which one fits?
Each solution class solves a different problem, and picking the wrong one is the single most common threshold mistake.
Rubber wedge ramps are the quick fix. They need no fixings, install in minutes, and grip well underfoot and under tyre. Suppliers in Australia typically size them for lips between roughly 6 mm and 40 mm, which covers most internal step-downs and many external door lips. They suit renters, temporary fixes, and anyone testing a layout before committing to a permanent build. The trade-off: check the UV rating before leaving one outdoors long-term, and confirm the weight rating if a power wheelchair or scooter will cross it daily.
Aluminium thresholds and fixed ramps step up in strength. They handle heavier scooters and repeated daily traffic better than rubber, and they’re the semi-permanent middle ground between a wedge ramp and a full rebuild. Check the fixation method (screwed, adhesive, or recessed), and be aware aluminium conducts heat and cold, which matters on an exposed external doorway.
Integrated flush thresholds with drainage channels are the long-term answer for external doors. A recessed drainage channel, often at least 50 mm deep, lets the entry sit level while still managing surface water under NCC rules. This option needs a builder or door installer involved from the slab stage, not bolted on afterwards.
Whatever you’re comparing, check five specs before buying: load rating, width, slip resistance, outdoor UV resistance, and whether the product actually fits within your door jamb without fouling the swing.
How do you measure and calculate the right ramp gradient?
Getting the numbers right up front saves you buying the wrong product twice. Work through it in this order:
- Measure the highest point of the lip. Use a spirit level and tape measure at the tallest edge of the step or sill, not the average. This figure is your rise.
- Measure the clear opening width. Measure from the door stop to the face of the fully open door leaf. Livable Housing guidance sets this at 820 mm minimum for specified doorways, and a door leaf that size typically needs to be around 870 mm or wider once you account for the stop and hinge.
- Measure jamb depth if the threshold sits inside a recessed frame, since this affects whether a ramp will sit flush or catch on the frame.
- Calculate the gradient. Divide the rise by the ramp length you’re considering. A 30 mm rise over a 240 mm ramp gives a gradient of 1:8, right at the compliant limit. The same 30 mm rise over 280 mm gives a gentler 1:9.3, well within range.
Pro Tip: Round up the ramp length, not the rise. A slightly longer ramp is always safer than a slightly steeper one, and the extra length rarely costs more.
Manual wheelchair users generally need the gentlest gradient you can fit, since pushing uphill on 1:8 unassisted is hard work over even a short distance. Mobility scooters and power wheelchairs cope with steeper approaches more comfortably, but neither should be pushed past the 1:8 ceiling regardless of the chair doing the work.
Before you buy anything, confirm the maximum supported rise, overall length, load rating, width, outdoor rating, and slip resistance standard against your own measurements, not the product photo.
Should you install it yourself or call a professional?
A rubber wedge ramp is genuinely a DIY job, although avoiding common pitfalls is important to ensure a safe and effective installation. Sit it against the lip, check it doesn’t rock, and confirm the leading edge sits flush with the floor so nothing catches a front caster.
Anything permanent is a different conversation. Fixed aluminium ramps, integrated drainage channels, and slab set-downs all need a builder, certifier, or specialist installer, because getting the drainage wrong turns an accessible entry into a water ingress problem. Before signing off on any of these, ask for:
- Evidence of load testing and slip resistance for the specific product
- A clear explanation of how drainage or weatherproofing is being handled
- Written warranty terms and a maintenance schedule
Ongoing upkeep is simple but easy to skip: clear drainage channels of leaf litter each season, check rubber ramps for UV cracking, and retighten any fixings on aluminium ramps after the first few months of thermal expansion and contraction.
Why installers push for flush entry over ramps
Flush, step-free entry is the outcome every accessibility-minded installer wants, because it removes the failure point entirely rather than managing around it. The barrier is rarely the door itself. It’s drainage, slab height, and hardware, since reconciling AS 1428.1 access requirements with AS 2047 water-penetration standards on an external door is a routine specification challenge, not an edge case.
Ask any supplier three things: what load and slip-test evidence backs their threshold product, how they’re managing drainage at that specific doorway, and what the warranty covers once it’s installed. Door hardware matters just as much as the threshold itself. Handle height, closer force, and landing space all affect whether the entry actually works for a wheelchair user day to day.
How does NDIS funding work for threshold upgrades?
Threshold ramps and accessible doorway modifications can fall under NDIS home modification funding when they’re linked to a participant’s assessed need, but the pathway isn’t automatic. A minor modification, such as a rubber wedge ramp or a small threshold ramp, usually needs to be recommended in a support plan or by a treating allied health professional. More substantial changes, like an integrated flush threshold with drainage, a rebuilt slab, or a widened doorway, almost always require a formal assessment first.
That’s where an occupational therapist earns their place in the process. An OT assesses the person’s mobility aid, transfer ability, and daily routine, then writes a report that justifies the specific modification to the funding body. Without that assessment, a builder can quote the work, but the funding request has nothing to stand on.
Bring a builder or certifier into the conversation once the OT’s recommendation is in hand, particularly for anything touching the slab, drainage, or a door’s structural opening. They’ll confirm the modification actually meets AS 1428.1 and NCC requirements on paper, not just on-site. Skipping this step is one of the more expensive mistakes families make. A ramp installed without sign-off can fail a later compliance check, leaving the household to redo the work at its own cost. If you’re not accessing NDIS funding, the same logic still applies: get the OT’s functional assessment first, then match the standard to the person, not the other way around.
What does a wheelchair friendly threshold cost to install?
Costs scale sharply with permanence, and it pays to know where the jumps happen before you commit.
A rubber wedge ramp sits at the cheapest end, typically running from around $50 for a small internal step-down to a few hundred dollars for a wider, heavier-duty outdoor model rated for scooters. No installation labour is needed since these are placed, not fixed.
Aluminium threshold ramps cost more upfront, generally landing in the low hundreds for a basic fixed unit, climbing higher for custom widths or heavier load ratings. Add installation labour if it’s being screwed or bonded into place rather than simply set down, though many aluminium options are still simple enough for a competent DIYer to fit.
Integrated flush thresholds with drainage channels sit at the top of the range because they involve a builder, sometimes a certifier, and slab or frame modification. Costs here vary enormously depending on whether it’s a straightforward retrofit or a full doorway rebuild with a new drainage channel, door frame, and flooring transition, and they’re best quoted on-site rather than estimated from a price list.
Whichever tier you’re in, get at least two quotes for anything beyond a rubber ramp, and ask each installer whether their price includes compliance checking against AS 1428.1, not just the physical fit-out.
How long does it take to buy and install a threshold ramp?
Timelines vary as much as costs do. A rubber wedge ramp is close to instant. Order online or grab one from a mobility supplier, and it’s usable within a day of arriving, no waiting on trades.
Aluminium ramps take longer. Expect one to two weeks between ordering a made-to-measure unit and having it fitted, mostly waiting on manufacturing and scheduling an installer if you’re not fitting it yourself.
Integrated flush thresholds are the slow end of the scale. Between the OT assessment (if funded), a site measure, a certifier review where needed, manufacturing of a custom door or frame, and the actual build, four to eight weeks isn’t unusual, and longer if drainage or slab work is involved. Building this timeline in early, especially if you’re coordinating NDIS approval alongside the physical work, avoids the scramble of needing an accessible entry before the paperwork or trades can catch up.
What are the common mistakes when choosing a threshold solution?
The biggest red flag is a product with no stated gradient, rise, or length. If a supplier can’t tell you the numbers, they can’t tell you whether it’s compliant, and you’re buying blind.
A close second is ignoring outdoor exposure. A rubber ramp with no UV rating left on a north-facing entry will crack and harden within a season or two, turning a grippy surface into a brittle trip hazard. Check the rating before buying, not after it fails.
Buying on rise alone, without checking length, is another trap. A ramp advertised as handling a “35 mm rise” might only do so over a length that pushes the gradient past 1:8. Always calculate the actual gradient yourself rather than trusting a headline number.
Skipping the load rating is a mistake that shows up later, not immediately. A ramp fine for a manual chair can flex, crack, or shift under a heavier power wheelchair or scooter, so match the rating to the heaviest mobility aid that will use it, not the lightest.
Finally, watch for installers who treat drainage as an afterthought on external doors. A flush threshold that floods the first heavy rain is worse than the step it replaced, and it’s the number one reason integrated solutions need proper coordination between the builder, the door supplier, and, where required, a certifier.
Does the threshold solution depend on your door type or flooring?
It does, and this is where a lot of otherwise good plans fall over. Sliding doors, for instance, often run on a track that already sits proud of the floor, which limits how flush any threshold solution can realistically go without relocating the track itself. Hinged doors give more flexibility, since the threshold detail sits independent of the door’s operating mechanism.
Door material matters less than door thickness and frame depth. A standard security door frame has a set depth that determines how much room exists for a recessed or integrated threshold, so it’s worth checking frame specifications before assuming a flush solution will fit without modification.
Flooring transitions add another layer. Moving from tile to timber, or from an outdoor paved surface to indoor flooring, often creates the exact height difference that needs solving in the first place. A rubber wedge ramp bridges most flooring mismatches without touching the floor covering, which makes it the lowest-risk option when you’re not ready to commit to a full renovation. An integrated threshold, by contrast, usually means coordinating with whoever is laying or relaying the floor, since the channel or recess needs to sit correctly against both surfaces.
If you’re planning a new or replacement door alongside the threshold work, it’s worth discussing the frame and sill detailing with your custom door supplier at the same time, rather than fitting the threshold first and hoping the door matches later.
Our take: standards first, product second
Most threshold advice online starts with product recommendations and works backwards to compliance. That order is wrong. Start with AS 1428.1’s numbers, measure your actual doorway against them, and only then look at rubber, aluminium, or integrated solutions. A ramp that looks right in a supplier’s catalogue photo can still fail on your specific rise-to-length ratio.
The conventional wisdom oversells ramps as the default fix. They’re a retrofit for a problem that ideally shouldn’t exist. Where a renovation or new build is on the table, flush entry with proper drainage detailing beats any ramp, because it removes the ongoing maintenance and the gradient risk entirely rather than managing around them.
If there’s one thing worth prioritising first, it’s the measurement, not the shopping. Get the rise, the clear opening width, and the gradient calculation done before you look at a single product listing. Everything else, from budget to timeline to installer choice, falls into place once those three numbers are locked in.
— MYBMC
Get a compliant, custom-fitted door and threshold sorted properly
Getting the threshold right often means getting the door right first, and that’s where a specialist custom door provider comes in. Such providers handle design consultation, measurement, manufacture, and installation of aluminium, steel, and stainless doors, built to fit your existing frame and floor transition rather than forcing a generic size onto your doorway.
A quote starts with a proper site measure, so any threshold, sill, or clear opening issue gets caught before manufacturing, not after. You’ll get a clear compliance check against your doorway’s actual dimensions and a realistic installation timeline, rather than a guess pulled from a catalogue. If you’re weighing up a new door alongside a threshold upgrade, browse the range of aluminium, steel, and stainless steel doors and request a quote to get the measurements and options sorted in one visit.
Sources
The Livable Housing Design Standard sets the clear opening and level entry rules. The AS 1428.1 ramp guidance confirms the gradient, rise, and length limits used throughout this guide.
- Ramps and handrails: NCC/BCA ambiguity meets AS 1428.1 clarity
- Livable Housing Design Standard 2022
- Livable housing threshold whitepaper (Stormtech / customgrate)
FAQ
What are wheelchair accessible thresholds?
They’re entry points that are either flush and level, have a rounded sill of 5 mm or less, or use a ramp meeting AS 1428.1’s 1:8 gradient, 35 mm rise, and 280 mm length limits.
What is the Australian standard for wheelchair ramp slope?
AS 1428.1 sets the maximum gradient for threshold ramps at 1:8, alongside a maximum rise of 35 mm and a maximum length of 280 mm.
How do you get a wheelchair over a threshold?
Use a rubber wedge ramp for a quick, tool-free fix on lips under about 40 mm, or a fixed aluminium ramp for heavier daily use with a power wheelchair or scooter.
Can a wheelchair fit through an 820 mm door?
An 820 mm clear opening, measured from the door stop to the fully open leaf, is the minimum required under Livable Housing guidance for specified doorways and generally allows most manual and powered wheelchairs to pass through comfortably.