A services locating survey for a commercial building in Sydney is a combined job: underground services are located on site, picked up by survey, and delivered as a drawing your design team can work from. It is commissioned before design is locked in, not the week before excavation.
A services locating survey for a commercial building in Sydney is a combined job: underground services are located on site, picked up by survey, and delivered as a drawing your design team can work from. It is commissioned before design is locked in, not the week before excavation. This guide sets out what the survey covers, what to ask for at each stage, and where commercial sites tend to go wrong.
What a services locating survey covers
Three pieces of work sit inside the one deliverable:
- Records search. Before You Dig Australia plans, asset owner records and any existing site drawings.
- Site locate. Services traced with electromagnetic and ground penetrating radar equipment, pits lifted, connections confirmed.
- Survey and drafting. Located positions measured to coordinates and levels, then drafted with each service labelled by type and quality level.
The result is a plan or 3D model showing electricity, communications, gas, water, sewer, stormwater and fire services across the site and the adjoining road reserve.
Why commercial sites are harder than houses
A house has a handful of private services. A commercial property has decades of them. Car parks carry lighting circuits, private hydrant and sprinkler mains, trade waste, grease arrestor lines, and data links between buildings. Each was added by a different contractor, and the as-built drawings, where they exist, are often wrong.
Location adds to it. In the Sydney CBD, North Sydney and Parramatta, the street outside may hold high-voltage feeders, large water mains and communications routes in a congested footpath. Basement excavation, shoring and anchors all reach into that zone. The cost of an unknown service on a commercial project is measured in programme delay, which is why the survey is worth doing early.
What to commission at each stage
Match the scope to the decision in front of you:
- Due diligence and feasibility. A records search and site walk (QL-D and QL-C) to learn which authorities' assets affect the site.
- Concept and detailed design. A full QL-B locate and survey across the site and frontage, so engineers design around real positions.
- Pre-construction. QL-A potholing at clash points, crossings and anywhere the design depends on an exact depth.
- Construction. Re-marking before excavation, and scanning of existing slabs before coring.
The quality levels come from AS 5488-2022, published by Standards Australia. Buying the QL-B survey at design stage and the QL-A points later is normal. Buying nothing until the excavator arrives is the expensive version.
Why the locate and the survey should be one job
It is common to see a locator mark the site one week and a surveyor arrive the next to pick up faded paint. Marks get driven over, washed off or misread, and the surveyor has no way of knowing which line was which service.
When locators and surveyors work together, each service is measured as it is traced, and the person drafting it knows how confident the locate was. LCG Locating is part of a registered surveying practice, so utility survey and mapping is produced in-house and certified by LCG's registered surveyors.
The deliverable your design team needs
Ask your civil and structural engineers what format they want before you brief the survey. Typical requirements:
- DWG or 12D model on the project datum, normally GDA2020 and AHD levels
- 3D strings for each service, not flat linework
- quality level attached to every segment
- pit and lid details, with invert levels where they could be measured
- a written report listing methods used and services not located
A PDF with coloured lines is fine for a site meeting. It is no use to someone modelling a basement. The range of outputs LCG provides is set out on the deliverables page.
What the survey will not find
No survey is complete, and the report should say where it is not. Non-conductive pipes without tracer wire, services below radar range in clay, and anything under a building footprint that cannot be accessed may remain unconfirmed. Services inside an occupied building, above ceilings and in risers, are outside the scope of a subsurface survey altogether.
A good report draws a boundary around what was investigated and lists the records that could not be verified. Treat that list as the brief for the next stage of potholing, not as a failure.
Existing buildings: slabs, drainage and tanks
Refurbishments and additions raise further questions. Cutting or coring a slab needs concrete scanning for reinforcement, post-tension tendons and conduits. Older sites may hide underground fuel tanks, redundant pits or voids, and drainage that nobody has mapped.
Adding these to the same commission is cheaper than calling them up one at a time. Mention the building's age and former uses when you ask for a price. A site that was once a service station or a workshop changes what the investigation should look for.
Access, approvals and timing
Commercial sites rarely allow a free run. Plan for:
- after-hours or weekend work in trading car parks
- building management inductions and permits
- traffic control for the road frontage
- road occupancy approval from council or Transport for NSW for work in the carriageway
SafeWork NSW places the duty to identify underground services on the person managing the excavation, so the principal contractor will want this report in hand before breaking ground.
Next step
Send a site plan, the project stage and the format your engineers need through our contact page. We will scope the survey to the decisions you need to make now and flag what can wait.
Common questions
What is a services locating survey?
A services locating survey finds the underground utilities on a site and records their positions by survey. It combines a records search, on-site detection with electromagnetic and radar equipment, and drafting of the results as a plan or model. Each service is labelled with its type and its AS 5488 quality level.
When should a commercial project commission one?
Before detailed design starts. Engineers need real service positions to set basement lines, footings, drainage and new connections. Commissioning it at design stage avoids redesign later. Potholing to confirm exact depths at clash points can follow once the design is developed.
Is a utility survey the same as a land survey?
No. A land or detail survey records boundaries, levels and visible features. A utility survey records what is underground. They are often delivered together on the same datum, and a detail survey usually shows only the pit lids, not the services between them.
How long does a services survey take on a commercial site?
It depends on the site area, service density and access restrictions. A small commercial lot may be located in a day with drafting to follow, while a large or congested site takes longer. After-hours access requirements often govern the programme more than the survey itself.
Who is responsible for underground services on a building site?
The person conducting the business or managing the excavation carries the duty to identify services before work starts. In practice the developer commissions the survey for design, and the principal contractor verifies and re-marks before excavation.