A free enquiry that takes minutes to lodge sits between a routine bulk excavation and a project that stops while a distributor repairs a high voltage feeder. That is the whole shape of this subject. The search costs nothing, the information it returns is deliberately approximate, and the gap between the two is where most of the money gets lost.
Excavation duties are statutory, and they attach to whoever has management or control of the workplace, which on a development site can be the developer, the head contractor, or both at different moments. The officers of those entities carry a separate personal due diligence duty. Prosecutions tend to follow incidents rather than intentions. How those duties sit across your particular project structure is a question for a construction or work health and safety lawyer, and the questions worth putting to one are set out near the end of this guide.
Figures, clearances and section numbers here were current at the date of writing and they do change, sometimes with very little notice. Every regulatory point below links to the regulator or the legislation it comes from, and that link is where to confirm the position on the day you rely on it.
What is Before You Dig Australia, and what does the search actually give you?
Before You Dig Australia is a free national referral service. You lodge an enquiry describing your dig site, and asset owners registered with the service who hold infrastructure in that area send you their plans and their working instructions directly.
It is a referral service, not a survey. Before You Dig Australia describes itself as a single point of contact for requesting information about underground networks at a planned project site from its registered members, without the need to contact each of them individually. The organisation was formerly called Dial Before You Dig, and the Department of Infrastructure, Transport, Regional Development, Communications, Sport and the Arts records the rename as a merged entity with no change to the service itself. A lot of site documentation still says “Dial Before You Dig”, and older specifications referencing the old name are pointing at the same process.
What comes back is a confirmation sheet listing every affected asset owner with their contact details, followed by the owners’ own responses. Those responses arrive separately, by email, from each owner. The service states that members are encouraged to respond within two business days, which means a full set of plans on a complex urban site is a several-day exercise rather than a same-day one, and is worth treating as a lead time in the programme rather than a task.
Three things about the mechanics tend to surprise developers.
The enquiry is free, but the information is not always. Before You Dig Australia notes that asset owners may charge for supplying infrastructure information, and that this is “normally only for large development related enquiries or planning/design enquiries where no excavation is taking place”. The design-stage enquiry, which is the one you want early, is precisely the category most likely to attract a fee.
Plans expire. Each asset owner sets its own expiry date on the information it sends, and the dates vary between owners on the same site. A set of plans obtained at feasibility stage will generally be stale by the time the excavator arrives, and a fresh enquiry is required to have current plans on site.
Receiving everything is not permission to start. The service is explicit that “the receipt of all Before You Dig responses is NOT considered to be an approval to proceed with excavation”, and that each asset owner’s own requirements, which may include a permit, a supervised location, or a physical presence on site, have to be satisfied separately. On a site with a transmission asset or a high pressure gas main, that owner-specific process can take considerably longer than the plans did.
Why the plans that come back are not a location of your services
The plans indicate that something is present in an area. They do not tell you where it is.
Before You Dig Australia states this in its own terms: the information “does not pinpoint the exact location of the infrastructure asset”, and the plans are “indicative only”, because asset owners record general locations rather than exact measurements. Three reasons are given, and each of them matters more on an infill development site than on a greenfield one.
Ground profiles change. An asset installed thirty years ago sits at a depth measured from a surface level that may have been cut or filled several times since. Depths and alignments are therefore frequently not supplied at all, and where they are, they describe conditions at installation.
The recorded owner often did not lay the asset. Domestic connections are routinely installed by builders, contractors or previous owners, and the network operator has no record of the work.
Most buried assets predate accurate spatial technology. A line drawn on a plan from a 1970s installation carries whatever accuracy the method of the day allowed.
The consequence for a developer is specific. Domestic services, meaning anything that terminates within the property, generally do not appear on the plans at all. The service states plainly that domestic services do not typically appear on the plans it distributes, which mainly show network services, and that privately installed items such as irrigation, a power run to a shed, septic tanks or abandoned pipework will not be indicated. On a demolition and rebuild site, the assets most likely to be struck during bulk excavation are exactly these: the live sewer junction serving the neighbour, the lead-in that was never abolished, the old fibre run to a building that no longer exists.
Not every owner is a member either. Before You Dig Australia notes that while most asset owners participate, some, including some councils, do not, and only the owners listed on your confirmation sheet have been consulted. A council-owned stormwater line on a site whose council is not a member will simply be absent from the pack.
Assets are also not laid in straight lines. The service warns against assuming depth or alignment, because installers went around obstacles that may no longer exist. The trap in a bulk excavation sequence is not the asset nobody knew about; it is the known asset assumed to run parallel to a boundary that in fact deviates two metres around a tree that was removed in 1998.
What does the law require before you break ground?
The duty is to obtain current information about underground essential services before excavation starts, and to pass it to whoever carries out the work. It is a duty on the person with management or control of the workplace, which on most development sites is a live question rather than an obvious one.
New South Wales and the model work health and safety states
In New South Wales the provision is section 304 of the Work Health and Safety Regulation 2025 (NSW), which replaced the 2017 Regulation. The 2025 instrument largely preserves the previous framework but renumbers and renames: provisions are now “sections” rather than “clauses”, so site documentation still citing “clause 304 of the 2017 Regulation” is referring to a repealed instrument even where the substance is unchanged. Anything in your safety documentation, contract specifications or consultant briefs carrying the old citation may be worth a pass.
SafeWork NSW states the duty in two sentences: “When excavation work is carried out, get information about the underground essential services that are at the site and at any adjacent areas, before work commences. Give that information to anyone you engage to carry out the excavation work.”
Two features of that wording carry weight on a development site. The duty extends to adjacent areas rather than only the land you own, which matters where excavation runs to a boundary or where a neighbouring asset runs within your zone of influence. And the duty to hand the information on means the information cannot sit in a consultant’s folder unread by the people operating the plant.
Underground essential services are defined by reference to services using pipes, cables or other associated plant located underground, and the information contemplated includes location and depth for gas, water, sewerage, telecommunications, electricity, and chemicals or refrigerant in pipes or lines. The records are to be kept until the excavation work is completed, and for at least two years where there has been a notifiable incident.
The model work health and safety framework operates in Queensland, South Australia, Western Australia, Tasmania, the Australian Capital Territory, the Northern Territory and the Commonwealth jurisdiction, and the excavation provisions in each follow the same substance, though the numbering can differ between jurisdictions. The practical differences between those jurisdictions tend to sit in the regulator’s guidance and in the asset owners’ own permit processes rather than in the regulation text. Confirming the current provision with the relevant regulator before relying on a section number is worthwhile, because the regulations are remade periodically and New South Wales has just demonstrated how quietly the numbering can move.
Victoria
Victoria sits outside the model framework. The duties arise under the Occupational Health and Safety Act 2004 (Vic) and the Occupational Health and Safety Regulations 2017 (Vic), and WorkSafe Victoria’s Compliance code: Excavation is the practical guidance on how to meet them. The status of a compliance code is worth understanding: WorkSafe states that “if you comply with a code, you are deemed to comply with the Act or Regulation duty covered by the code”, while the codes themselves are not mandatory and duty holders may achieve compliance another way. Departing from the code is therefore permitted but shifts the burden of demonstrating compliance onto you.
Victoria also has a co-published guidebook. WorkSafe Victoria and Energy Safe Victoria’s guide to undertaking work near underground services sets out the No Go Zones for underground assets, described by WorkSafe as distances the two regulators “recommend be applied as best practice” to protect workers, reduce damage to services and plant, and avoid service interruptions and the costs that follow them. Note the framing: recommended best practice rather than a regulation, which again means that a departure is a position you may have to justify.
New Zealand
New Zealand runs an equivalent referral service under the name beforeUdig. The operator describes lodging an enquiry at least two full business days before starting any excavation, and points to WorkSafe New Zealand’s excavation guidance and its guide for safety with underground services as the governing material.
The published practice mirrors the Australian position closely, and in places states it more bluntly. The plans indicate the presence of assets in the vicinity and do not pinpoint exact location. A small number of New Zealand asset owners are not members, so the pack received should not be assumed to represent every asset affected. Potholes are to be dug by hand or by non-destructive means such as vacuum excavation, with positions and depths marked on the plans. Where an asset owner such as a high pressure gas or water operator requires a site inspection and a permit to dig, the service describes following those instructions as a legal obligation rather than a courtesy. And where the scope or area of work changes, or the plan validity dates expire, a fresh enquiry is required and work is to stop until it is received.
For a developer working across the Tasman, the process shape transfers. The statutory framework and the asset owners do not, and both need confirming locally.
What are the AS 5488 quality levels, and which one does your project need?
AS 5488 is the Australian Standard that classifies how reliable your subsurface utility information actually is. It sets out quality levels from D up to A, and the value of the framework for a developer is that it converts a vague question, “do we know where the services are”, into a contractible one.
The standard is published by Standards Australia in two parts, one covering the classification of subsurface utility information and one covering subsurface utility engineering, and it has been revised since its original 2013 edition. Confirming the current designation and edition through the Standards Australia catalogue before citing it in a consultant brief is worth the minute it takes, because specifications written a few years ago may reference a superseded part.
The levels describe method, and method is what you are buying.
Quality level D is records. Plans, as-built drawings, historical data and the pack that came back from your Before You Dig Australia enquiry, with nothing verified in the field. Every project starts here by default, and a surprising number of projects go to tender still here.
Quality level C adds a survey of what you can see. Pit lids, manholes, valve boxes and marker posts picked up and located. It tells you a service exists and roughly where it enters the site, and it tells you nothing about the run between the visible points.
Quality level B adds geophysical detection. A locator uses electromagnetic equipment, and on some sites ground penetrating radar, to trace the line of the asset and mark it on the surface, which is then picked up by survey. This is the level at which you start to have a plan you can design against. The standard specifies the tolerances that attach to each level, and the specific figures sit inside the paid standard rather than in any public source, so they are worth reading directly before you write them into a scope.
Quality level A is physical exposure. The asset is uncovered, usually by vacuum excavation or careful hand digging, and its position and depth are surveyed where you can see it. This is the only level at which depth is genuinely known rather than inferred, and it is the level the asset owners’ own instructions frequently require before mechanical excavation may proceed near their plant.
The framework is used by government infrastructure agencies to specify the investigation they require, which gives it a second use for a developer: it is a defensible way to describe what you have and have not done. A contract that says “services located” invites an argument. A contract that says a nominated quality level has been achieved across a defined area, with a plan attached, does not.
Choosing a level is a commercial decision rather than a technical one, and it is best framed as a question about consequence. What is in the ground, how deep does the excavation go, how bad is a strike on the worst asset present, and how much of the programme sits downstream of the excavation? A single storey extension on a suburban block and a three-level basement under a corner site with a transmission feeder in the verge are not the same problem even though both start with the same free enquiry.
Where does service investigation sit in the development programme?
Twice, and the two occasions do different work.
The first is due diligence, before or during the option or contract period, and the question it answers is whether the site can carry the yield you have assumed. A trunk sewer through the middle of the developable footprint, a high voltage cable in the setback, a gas main that constrains where you can put a basement ramp: these are feasibility inputs, not construction issues, and finding them after settlement is finding them too late. The design-stage enquiry is the one asset owners may charge for, and it remains among the cheapest lines in a due diligence budget. This sits naturally alongside title searching and the relevant planning certificate work, such as the section 10.7 certificate in New South Wales, and the results should be read together, since an easement on title and an asset in the ground are two halves of the same constraint.
The second is pre-construction, close enough to the excavation that plans have not expired, and the question it answers is where to dig. This is where quality level B and, near sensitive assets, quality level A work belongs, along with whatever permit each asset owner requires.
Between the two sits design. Detailed design done against quality level D records and later corrected against quality level B survey is design done twice, and the second pass typically lands during the documentation crunch when there is no float to absorb it. The surveyor engaged for the feature survey is often the natural party to pick up located services into the same drawing, and asking for it at that point tends to be cheaper than commissioning it separately later.
The lead times worth carrying in the construction programme are the asset owners’ responses, the locator’s mobilisation, and, where a permit or a supervised location is required by an asset owner, that owner’s own turnaround, which is the one nobody prices and the one most likely to bite.
What does a service strike actually cost a development?
The repair bill is generally the smallest part of it. The cost sits in four places, and only one of them appears on the invoice from the asset owner.
Repair and reinstatement. The asset owner repairs its own plant and pursues recovery. Before You Dig Australia states that “court proceedings may commence against individuals and/or companies for the recovery of cost of repairing or reinstating damaged assets where negligence appears to be a contributor”, and that lodging an enquiry does not displace the duty of care of the person digging. Programme. This is usually the expensive part. An excavation stops, a regulator may attend, the asset owner controls the repair sequence and its own crew’s availability, and everything downstream of the excavation moves. On a project where the excavation sits on the critical path, which is most of them, the delay flows straight into holding costs, finance costs and any dates you have contracted to.
Third party consequential loss. A severed fibre trunk or a distribution feeder takes out service to other properties. This is where the numbers become unpredictable and where the insurance position needs to have been settled well in advance rather than discovered afterwards.
Insurance and regulatory exposure. Before You Dig Australia notes that a property owner’s insurance may not respond where it can be shown that no enquiry was lodged. The work health and safety exposure runs in parallel and is not covered by a construction policy.
The way this lands in the numbers is straightforward. A strike is a contingency event, not a budget line, and it belongs in the construction contingency conversation alongside the other subsurface unknowns. Investigation spend reduces the probability of the event; it does not eliminate it, because unregistered and privately installed assets exist on sites where every registered asset has been located to quality level A.
There is no published benchmark for what service location costs in Australia. Locator pricing is quoted per site and moves with the area to be scanned, the number and type of services present, ground conditions, whether ground penetrating radar is required, whether non-destructive digging is included, and whether the work is done in traffic. A term quote against a defined scope and a nominated quality level is the only honest way to get the number, and getting two is worth the delay. What can be said is the shape of the trade: the investigation sits with the other pre-construction consultant fees in the total development cost, and the event it is protecting against sits in a different order of magnitude entirely.
Who pays to move a service that sits where your building goes?
The developer, in almost every case, and through a process controlled by the asset owner rather than by your programme.
Where an existing asset runs through the footprint you intend to build on, locating it is only the first step. The asset then has to be adjusted, protected, or abolished, and each utility runs its own approval process with its own design requirements, its own accredited designers and constructors, and its own fees. In New South Wales, for example, Sydney Water states that work to move, remove or replace any of its pipes, including temporary replacement pipes, must not start until approval is given. A water servicing coordinator has to be engaged, an approval application lodged with a design of the proposed works and any temporary pipework, and the response may include a requirement to lodge a construction bond. On who carries the cost of extending or amplifying the system to service a development, Sydney Water’s published position is that “generally, the developer pays for the full cost, but sometimes we will pay”, with the answer governed by its funding policy rather than negotiated. Equivalent processes exist for the electricity distributors, the gas networks and the telecommunications carriers in every state, under different names.
Three characteristics of these processes are worth knowing before you rely on them in a programme.
They are sequential and long. Design, approval, construction and commissioning happen in order, and the utility’s queue is not responsive to your settlement date.
They are not optional. Building over or adjacent to an asset without the owner’s approval creates a problem that surfaces at subdivision or occupation stage, when the cost of fixing it is at its highest.
They are priced by the asset owner. There is no competitive tension on the approval component, and the construction component is frequently restricted to accredited parties.
The practical consequence for feasibility is that an asset discovered in due diligence is a cost and a programme item you can model. The same asset discovered after the site is bought is a cost, a programme item, and a design change.
Overhead services: the part the underground search does not cover
Overhead powerlines are a separate exposure, governed by clearance rules that constrain both how you build and what you can eventually build.
The distance thresholds are set by the electricity safety regulator in each state. In Victoria, Energy Safe Victoria publishes a No Go Zone framework with three bands for distribution overhead powerlines, which range in voltage from 240V up to 66kV. Energy Safe states that work outside 6.4 metres from an overhead powerline attracts no specific No Go Zone requirement beyond the general obligations; work between 3.0 metres and 6.4 metres requires a registered Spotter, in what is known as the Spotter Zone; and work within 3.0 metres requires permission from the relevant network operator together with additional preventative measures.
For transmission overhead powerlines on towers, which range from 132kV up to 500kV, the same regulator sets the bands at outside 10 metres, between 8 and 10 metres with a registered Spotter, and within 8 metres requiring network operator permission.
Scaffolding is treated separately and more restrictively. Energy Safe states that a Permit to Work from the distribution company may be required where scaffold or the erection process brings components “anywhere above or within 5 metres below and 4.6 metres horizontally to the side” of a powerline, and that the two regulators consider a Spotter to be an inadequate control during erection and dismantling, so the asset owner must be contacted directly in those cases.
The design consequence is the one developers miss. Energy Safe points to regulation 610 of the Electricity Safety (General) Regulations 2019 (Vic) as setting clearance requirements between structures and overhead powerlines by voltage, and notes that the required clearance “must be maintained at all times”, which brings sag and sway of the conductors into the calculation on top of the nominal distance. Sag and sway is assessed case by case against extreme weather conditions and construction standards, and the distribution business is the party who advises on it. A balcony, an awning or a parapet that clears the line on a still day at the drawn position may not clear it in summer at full sag.
Other states set their own distances through their own electricity safety regulators, and the numbers differ. The Victorian figures above should be read as an illustration of how the framework works rather than as a national rule, and the relevant state regulator is where to confirm the thresholds that apply to your site.
How does this land in the feasibility?
As three separate lines, and it is worth keeping them separate because they behave differently.
Investigation cost is a pre-construction consultant fee, known in advance, quoted against a scope, and small relative to almost everything else in the budget. It belongs with the surveyor and the geotechnical investigation rather than in the construction cost.
Asset adjustment or relocation is a construction and approvals cost with a long lead time, and it is the line most likely to be missing entirely from a feasibility prepared before the services were investigated. Where an asset is known to sit in the footprint, this is modelled as a real cost and a real programme sequence, not absorbed into contingency.
Strike risk is contingency. It is a probability-weighted exposure rather than a cost, and the investigation you have done is what moves the probability. Treating a residual risk as a line item overstates the budget; treating a known relocation as contingency understates it.
The programme consequences are where the compounding happens. A delay to bulk excavation is a delay to everything after it, which means it carries finance cost, holding cost and, on an off the plan project, pressure against contracted dates. That is the mechanism by which an event costing tens of thousands in repairs can cost several times that in total.
Contractually, the allocation of subsurface risk is where this becomes a negotiation. Under a design and construct contract, the treatment of latent conditions determines whether an unregistered asset discovered during excavation is the contractor’s problem or yours, and the answer generally turns on what information you provided and what the contract said you warranted about it. A quality level B or A plan handed to the contractor with a clear statement of its scope and its limits puts both parties in a better position than a set of indicative plans passed on without comment. Handing over a Before You Dig Australia pack as though it located the services is the worst of both: it is not a location, and passing it on as one invites the argument you least want during an excavation dispute.
What to ask your locator, engineer, lawyer and builder
These split across the people who hold the answers, and they land better before the scope is set than after the quote arrives.
For the utility locator or subsurface utility engineering provider:
- Which AS 5488 quality level does your quoted scope achieve, across what area, and where within the site does the achieved level drop?
- What detection methods are included, and which assets on this site are unlikely to be detectable by those methods?
- Are non-conductive services, such as older plastic water or gas lines without tracer wire, within the scope, and how will you treat them?
- Does the scope include non-destructive digging to expose and verify any assets, and if so which ones and how many?
- Will the located positions be picked up by a registered surveyor and delivered in a coordinate system that matches our design set, or delivered as surface marks only?
- What is the shelf life of the marks and the plan, and what would cause you to recommend re-locating before excavation?
- What did you find that was not on the asset owners’ plans?
For the civil engineer:
- Which services constrain the design as currently drawn, and which of those could be designed around rather than relocated?
- What does the excavation sequence assume about the position and depth of each service, and which of those assumptions are records rather than located positions?
- Which assets require protection during construction rather than relocation, and what does the protection detail involve?
- What is the realistic approval and construction lead time for each relocation, from each asset owner, and where does that sit against the programme?
For the construction or work health and safety lawyer:
- Who is the person with management or control of the workplace for excavation purposes at each stage of this project, and does that change when the head contractor takes possession of the site?
- What does the officers’ due diligence duty require of our directors specifically in relation to excavation and service location, and what evidence of it should exist?
- What are our obligations in relation to adjacent land where our excavation affects assets outside our boundary?
- How should the service investigation information be handed to the contractor so that the statutory duty is discharged and our contractual position is not compromised?
- Where does responsibility sit under our contract for an asset that was not on any plan and was not detectable, and does the latent conditions clause do what we think it does?
For the builder or contract administrator:
- What is the excavation methodology within the No Go Zones and near each located asset, and who holds each asset owner’s permit?
- What is the stop-work trigger and the escalation path when something unexpected is found, and who on site has authority to use it?
- Which asset owner processes are on the critical path, and when were they initiated?
The one thing worth carrying out of this
The free search is the beginning of the site investigation, not the site investigation. It tells you who to talk to and roughly what is there. Everything that follows, the located positions, the exposed depths, the asset owners’ permits, the relocation approvals, is work that costs money, takes time, and sits on the programme.
Developers who treat the enquiry as a compliance tick and move on tend to find the services with an excavator. Developers who treat it as the first output of a staged investigation, with a nominated quality level, a real lead time and a contractual position that matches what was actually done, tend to find them with a locator. The difference in cost between those two discoveries is not close.