Infinity Edge Pools in Brisbane: Cost, Engineering and QLD Fencing Rules
Wahoo Pool & Landscape ConstructionAn infinity edge, also sold as a vanishing or negative edge, is one pool wall built a few millimetres below the water line, so water spills over it into a catch basin and is pumped back. On a Brisbane block that one wall adds four pieces of work to a standard concrete pool: a second structure below the edge, a second pump circuit, structural engineering for a raised or partly suspended shell, and a plan for how the drop side meets Queensland's pool barrier rules. We price it as an itemised upgrade after a site assessment, because the height of the drop drives most of the cost.
Infinity, negative, zero or wet edge: are they the same thing?
Mostly it is a naming question. Infinity, vanishing and negative edge all describe a pool where one or more walls spill into a basin set lower than the pool, usually facing a view. Wet edge and zero edge are more often used for water held flush with the coping and spilling into a slot or channel at deck level, with no visible drop. Both need a balance tank and a second circulation loop, so much of this guide applies to both. Our guide to wet edge and balance tank pools covers the flush version in more detail.
Does your block suit one?
An infinity edge earns its cost when three things line up:
- Fall across the block toward the outlook. A slope lets the basin sit below the pool without a deep trench. Ridge suburbs such as Bardon and escarpment blocks on Tamborine Mountain often have it.
- Something worth looking at from the water. A valley, the city, bushland or your own lower garden. If the edge faces a neighbour's fence, the edge frames the fence.
- Room and access below the edge. The drop face is a wall that has to be built, waterproofed, finished and later cleaned from the low side.
You can build one on a flat block, with the basin in a trench beside the pool, but most of the effect is lost. A flush wet edge often gives you the clean waterline for less. Our guide to designing a pool for a sloping Brisbane block covers levels, retaining and access.
What the edge adds to the price
Our 12 fixed-price packages run from $38,900 for a 5m x 3m plunge pool to $64,300 for the 10m x 4m Grand Pool, read from our catalogue on 21 October 2026 (see all pool packages). The Grand Pool package page lists infinity edges among the premium upgrades available on request. We do not publish a flat figure for the edge itself, and we would be wary of anyone who quotes one without seeing the site. These are the line items it brings:
| Line item | What drives the cost |
|---|---|
| Catch basin or balance trough | Volume (see the sizing example below), depth, and whether it is built into the drop wall or set in the ground below |
| Drop-face wall | Height of the drop, waterproofing, and the finish you will see from the lower garden |
| Weir | Length of the edge. It has to be dead level along its whole run or the water sheets unevenly |
| Second pump and plumbing | Flow over the edge, pipe runs back to the pool, level sensor and automatic top-up |
| Engineering | Structural design and certification for a raised or partly suspended shell (see the paperwork section) |
| Excavation and retaining | Usually the biggest variable on a slope: soil, rock and machine access |
| Landscaping below the edge | The area under the drop becomes the view from the house |
For a reference point, one national pool brand publishes $25,000 to $35,000 as the typical add-on for the edge alone. Use any single number as the start of a conversation. A 300 mm drop onto a garden bed and a 2 m drop down a retaining wall are different builds, and on a steep block the retaining walls are a separate cost again.
How big the catch basin needs to be
While the pool runs, water stands slightly above the weir and spills continuously. When the pump stops, or people get in, that water has to go somewhere, and the basin is where it goes. Your hydraulic design sizes it properly, but a rough example on an 8m x 4m pool (32 m² of water, the size of our Entertaining Pool I package) shows why basins end up bigger than people expect:
| Allowance | Rough volume | How it is worked out |
|---|---|---|
| Six adults getting in | about 480 L | A body displaces roughly a litre per kilogram: 6 x 80 kg |
| Water on the weir when the pump stops | about 160 L | 32 m² x 5 mm, if the water runs 5 mm above the weir |
| A 25 mm downpour on the pool | about 800 L | 32 m² x 25 mm |
| A 50 mm storm | about 1,600 L | 32 m² x 50 mm |
Nobody sizes a basin to swallow a summer storm. That water should leave through an overflow to the property's drainage. What the numbers show is that the basin needs three things: room for bathers and drain-back, a reserve so the pump never draws air, and an overflow. Ask to see the basin volume and the overflow connection on the drawings before you sign. Depending on where backwash and overflow water are discharged, a plumbing approval may be needed as well.
The vanishing side and Queensland's pool barrier rules
Every regulated pool in Queensland needs a compliant barrier, and the drop side of an infinity pool is where designs most often have to change. QBCC's guidance on the pool safety standard (Queensland Development Code MP 3.4) sets the core rules:
- The barrier must be at least 1200 mm high from finished ground level, and at least 1200 mm at every point on sloping or stepped sites.
- No gap under the barrier, or anywhere in it, can exceed 100 mm.
- The outside face needs a 900 mm non-climbable zone.
- Built walls, including retaining walls, can form part of the barrier if they meet the standard.
QBCC also allows the sides of an above-ground pool or spa to form part of the fence if they are at least 1200 mm high and non-climbable on the outside, with a fenced and gated access point. Ask your certifier early whether the drop wall of a raised infinity pool can be treated the same way on that side. A tall, smooth wall can work. Cladding joints, a ledge on the basin, a planter or a garden step near the foot of the wall can each give a child a foothold.
Then there is the catch basin. Queensland's Building Act 1975 defines a swimming pool as an excavation or structure that can be filled to a depth of 300 mm or more and is used for swimming, wading or a similar activity. Expect your certifier to look closely at a basin that holds that depth and sits where someone could climb or fall into it. The cheap fixes are settled on the drawings: keep the basin inside the fenced area, keep it shallow or fully grated, or fence it. Changing it after the shell is poured is expensive.
Your certifier must inspect the pool and its barrier before the pool is filled with water to 300 mm or more. Our 2026 guide to QLD pool fencing laws has the full rules. Treat this section as general information: the design that counts is the one your certifier approves.
The paperwork behind a raised or suspended pool
Three Queensland building forms matter here:
- Form 15, compliance certificate for building design. A structural engineer whom the certifier has accepted as a competent person certifies the design of the shell and the structure holding it up. On a slope, that design depends on the ground, which is why our site assessment includes test bores where the site calls for them.
- Form 16, inspection certificate. Issued at stages of the work. For a pool, the final stage is when the pool and its fencing are complete, before it is filled to 300 mm.
- Form 17, final inspection certificate for the pool and its fence. The certifier gives it to you and lodges the details with QBCC within five business days. If you sell or lease while it is current, it can stand in for a pool safety certificate.
Boundary setbacks come from your council's planning scheme and the engineer's design. There is no single statewide setback figure for pools in Queensland. If the edge sits near a sewer main or easement, read our guide to building a pool over a sewer line in South-East Queensland before you settle the position. Our compliance page sets out how we handle approvals.
What the second pump costs to run
The edge only works while water flows over it, which usually means a pump in addition to normal filtration. The running cost is pump power x hours x your electricity rate. Taking a 1.1 kW pump as an example, and the 2026-27 Default Market Offer cap for a single-rate plan in South-East Queensland (27.97c per kWh):
| How you run the edge | Energy | Approximate cost |
|---|---|---|
| 8 hours every day | 8.8 kWh a day | $2.46 a day, about $898 a year |
| 6 hours on Saturdays and Sundays only | about 686 kWh a year | about $192 a year |
Plenty of owners run the edge when they are using or looking at the pool and leave the rest of the day to normal filtration. A variable-speed pump turned down to hold a thin sheet of water uses less again, and a market plan below the cap lowers every figure in the table. Energex's controlled-load tariffs (Tariff 31 and Tariff 33) are cheaper and can run pool pumps, but supply on them can be switched off for up to 8 or 16 hours a day depending on the tariff. Ask your electrician whether the edge pump belongs on that circuit or on your main tariff.
Living with it
- The basin catches leaves, so trees hanging over the edge mean more cleaning. Plan planting below and beside the edge with that in mind.
- Moving water evaporates faster than still water. An automatic top-up and a level sensor protect the pump from running dry.
- Water running down the drop face leaves mineral marks over time. The finish you choose decides how much they show.
- Someone has to reach the basin and the drop face for servicing, so the design needs safe access on the low side.
Questions to ask any builder before you sign
- Is the edge priced as its own line item, separate from the base pool, retaining and landscaping?
- What is the basin volume, and where does the overflow go?
- Who prepares the structural design, and who signs the Form 15?
- How does the drop side meet the barrier rules, and is that shown on the plans?
- What finish goes on the drop face, and how will it be cleaned?
- Is the edge pump separate from filtration, and what is its rated power?
- What did the site assessment find about soil, access and services near the edge?
Frequently asked questions
How much does an infinity edge add to a pool in Brisbane?
It depends on the height of the drop, the basin and the engineering, so we quote it as an itemised line after a site assessment. One national pool brand publishes $25,000 to $35,000 as a typical add-on for the edge alone. Our packages start from $38,900 before upgrades.
Can you build an infinity pool on a flat block?
Yes, with the basin set in a trench beside the pool, but the effect is much weaker without a fall toward a view. A flush wet edge is often the better use of the money on a flat site.
Does the catch basin need a pool fence in Queensland?
Queensland's Building Act treats a structure that can hold 300 mm or more of water for swimming or wading as a swimming pool. Your certifier decides how the basin is treated, so settle it on the drawings: inside the barrier, shallow or grated, or separately fenced.
Do infinity pools cost more to run?
Yes, because a pump has to keep water moving over the edge. A 1.1 kW pump running 8 hours a day costs about $898 a year at South-East Queensland's 2026-27 single-rate cap of 27.97c per kWh, and about $192 a year if it only runs 6 hours on weekends.
Do I need an engineer for an infinity edge pool?
For a raised or partly suspended pool, yes. The structural design is certified on a Form 15 by an engineer the certifier accepts as a competent person, and the certifier inspects the work at stages.
Is an infinity edge the same as a wet edge?
Not quite. An infinity edge drops into a basin below, usually facing a view. A wet edge holds the water flush with the coping and spills into a channel at deck level. Both need a balance tank and a second pump circuit.
Next step: get the site looked at
If your block falls toward a view, a site visit tells you more than any brochure. Our $500 site assessment covers block measurement, excavation and access, an initial soil check with test bores where needed, and council overlays, followed by an itemised written quote. The deposit is refunded in full if you decide not to go ahead. If you would rather talk it through first, call 1300 924 666 or request a quote and mention the edge. If you are planning the garden at the same time, read whether you can build the pool and landscape together.
Sources
Queensland Building and Construction Commission, Pool fences. Queensland Government, Pool fences and barriers. Building Act 1975 (Qld). Business Queensland, Building forms (Forms 15, 16 and 17) and the Queensland Government's local government pool safety guideline (June 2024). Australian Energy Regulator, Default Market Offer 2026-27. Energex, Residential electricity tariffs. Package prices read from the Wahoo catalogue on 21 October 2026. This article is general information, not legal or engineering advice. Confirm requirements for your site with your council, a licensed building certifier and a structural engineer.
