What happens on the day the pool is excavated?
Dig day is the first irreversible step in a pool build and the one owners most want to watch. It is also the day that carries two obligations most people meet for the first time on the morning it happens. A concrete pool and a fibreglass pool diverge from here, and the first mandatory inspection falls at the end of it.
Excavation usually takes 1 to 2 days for a standard backyard pool. In Victoria a site fence must already be in place before digging commences, and completion of the excavation triggers the first of four mandatory inspection stages. A barrier is required once the hole holds 300mm of water.
The short answer
- Plan for 1 to 2 days of machine work, plus truck movements to take the spoil away.
- In Victoria the site fence goes up before the digger arrives, not after, and a fence is required between the house and the pool construction area.
- Completion of the excavation is mandatory notification stage one under regulation 169. The surveyor inspects the hole and the precaution measures.
- Regulation 116(3) requires any excavation to be fenced or otherwise guarded against being a danger to life or property.
- Once the hole holds 300mm of water — including rain — a complying AS1926.1-2012 barrier is required and must be maintained.
| Stage | Typically | What has to be true first | Where it slips |
|---|---|---|---|
| Site fence and hoarding up | The day before | Details are in the building permit, agreed with the surveyor | Fence hired for the wrong dates, or no fence between house and pool area |
| Machine and truck access | Morning | A path wide enough, and a gate or fence panel that comes out | Access narrower than the machine; a neighbour's driveway assumed, not asked |
| Service location | Before the first bucket | Underground services located and marked | Sewer, stormwater or comms line found the hard way |
| Bulk dig | 1–2 days | Setout pegs and levels confirmed against the approved plans | Rock, or groundwater, neither of which the quote priced |
| Spoil removal | Through the dig | Somewhere for it to go, and truck access to get there | Spoil stockpiled on site because trucks could not get in |
| Trim and clean-out | End of dig | Depths and falls to the approved design | — |
| Precaution measures restored | Before anyone leaves | The excavation fenced or otherwise guarded | Fence panels left down after machine access |
| Inspection 1 | Next working day | Excavation complete and precaution measures erected | Booked late, so the site sits open waiting |
The fence comes before the digger
The single most useful thing to know about dig day is that in Victoria one obligation is already overdue by the time the machine arrives, if nobody has handled it.
A site fence must be in place before any excavation for the pool or spa commences. Not once there is a hole — before there is one. A site fence or hoarding must be provided between an existing dwelling and the pool construction area, and where the pool is being built at the same time as the house, an additional site fence is required.
The surveyor has already assessed this. The building permit application should set out how the excavation will be fenced, and in approving it the surveyor considers the height of the barrier, whether there are footholds or handholds that could help a child climb it, the spacing of horizontal and vertical members, and the loads that could be placed on the structure. Where a gate is fitted in the site fence, the practice note recommends it comply with AS1926.1-2012; where there is no gate, the barrier stays closed except when access is needed and someone is present the entire time it is open.
For an owner this is a question to ask a week out, not on the morning: who is supplying the site fence, and is it up before the machine comes? Temporary fencing is also a line that quietly disappears from cheaper quotes. What differs between pool quotes covers the usual omissions.
What actually happens, hour by hour
A standard backyard excavation is one to two days of machine work. The variables are access, soil and where the spoil goes.
Access first. The machine has to reach the backyard. On a suburban block that usually means a fence panel or a gate comes out, and sometimes it means a smaller, slower machine and an extra day. If access is genuinely impossible, the alternative is a crane over the house, which is a different quote entirely.
Setout, then the bulk dig. Pegs and levels are confirmed against the approved plans, then the hole comes out in stages with the depths and falls trimmed to the design at the end. A pool with a deep end is not dug flat and then deepened.
Spoil goes out as it comes up. A backyard pool produces a serious volume of material, and it is measured in truckloads. Where the trucks cannot get close, it gets stockpiled on site and moved again later, which costs money and space. If you have anywhere legitimate to use clean fill on your own block, say so before the day, not after the trucks have gone.
Two things stop a dig and neither is unusual: rock, which turns a digger job into a rock-breaker job, and groundwater, which fills the hole as fast as it is emptied. Both are normally priced as allowances rather than fixed amounts, which is exactly why the allowances on page one of your contract are worth counting before you sign. Provisional sums and the soil test cover how to shrink that uncertainty in advance.
The inspection the day ends with
In Victoria, the completion of any excavation related to the installation of the pool or spa is the first mandatory notification stage under regulation 169. The surveyor cannot vary or omit it.
What they inspect is not just the hole. The state's own inspection sequence describes stage one as inspection at “completion of excavation and erection of precaution measures” — the dig and the guarding together, as one checkpoint. Regulation 116(3) requires that any excavation be fenced or otherwise guarded against being a danger to life or property, and regulation 116(1) requires the surveyor to consider protection of the public during construction.
The practical consequence is about timing. If fence panels came down for machine access and went back up, the site passes. If they came down and stayed down overnight, the site does not, and a precaution measure moved or altered so it no longer complies with the permit is the standard trigger for a direction to fix.
Where the surveyor determines that a complying AS1926.1-2012 barrier is required for the excavation itself, it can be installed and inspected immediately after the dig is finished. That is often the cheaper path, because it does the permanent barrier's job early instead of hiring temporary fencing for months.
The open hole, and the 300mm rule
Between the dig and the next stage the excavation sits open, and this is where the obligation people do not expect attaches.
As soon as the excavation, pool or structure contains more than 300mm of water, a barrier complying with AS1926.1-2012 must be erected and maintained. The rule does not care how the water got there. A hole in the ground after a wet week holds 300mm of water, and the requirement applies to a rain-filled excavation exactly as it would to a filled pool.
This is the main reason an open excavation is not a neutral state to leave a site in. It is also why the two pool types diverge from here. A fibreglass shell is placed in the hole and filled with water as part of the installation — so the barrier requirement arrives mid-build, immediately after filling. A concrete pool holds no water until the end, and the rule runs the other way: it must not be filled until the surveyor certifies a complying barrier exists.
If the build then stalls with the hole open, the problem compounds: the excavation still has to be guarded, the permit still has a six-month completion clock running in Victoria, and neither pauses. What to do when a build stops deals with that specific situation.
What to have ready, and what to ask the week before
Five questions, asked a week out, remove most of what goes wrong on the day:
- Is the site fence up before the machine arrives, and who supplies it? In Victoria this is not optional and not last-minute.
- How is the machine getting in, and what comes out to let it? Confirm the access width against the machine, not against the plan.
- Have underground services been located? A sewer main under the proposed shell can stop a design outright, and it is discoverable before anyone digs.
- Where is the spoil going, and how many truck movements? Tell your neighbours the number. It buys goodwill cheaply.
- When is the inspection booked? The site sits open until it happens, so a stage-one inspection booked for the same week is worth asking for.
On the day itself, keep children and pets inside while the machine is working, move the cars, and expect noise from early. If you are still choosing between builders, how precisely they answer those five questions is a reasonable proxy for how the rest of the build will go — and getting several quotes is the cheapest way to find that out. The full build timeline puts dig day in context.
Common questions
How long does it take to excavate a pool?
Do I need a fence before the pool is excavated?
Is there an inspection after the pool is dug?
What happens if it rains into the pool excavation?
What can stop excavation day?
Sources
- VBA Practice Note 05-2018 — Swimming Pool & Spa Safety
- Building Regulations 2018 (Vic), regulations 116 and 169
- VBA Practice Note 05-2018, as published by Mornington Peninsula Shire
- Australian Standard AS 1926.1-2012 — Safety barriers for swimming pools
General information only, current at 2026-09-16. Pool rules differ by state and by council, and penalty amounts are updated regularly. Confirm your own obligations with your council or a registered inspector before acting.
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