Somewhere on most Australian residential lots, somebody else has a right to do something on your land. The water authority might need to access a sewer pipe that runs under your back yard. Your neighbour at the rear of the block might have the legal right to drive their car across your driveway. The council might be able to dig up your front strip to repair a stormwater main. These rights are called easements, and they bind you and every future owner of the land.

An easement is a registered right that one parcel — the dominant tenement — has over another parcel — the servient tenement. The dominant land benefits from the right; the servient land bears the burden. As a vacant-land buyer, you are almost always on the burdened side. Easements come in many varieties: drainage and stormwater easements, sewer easements, water and recycled-water easements, easements for electricity, gas or telecommunications, rights of carriageway (for vehicle or pedestrian access), easements for support (so a neighbour's retaining wall can lean on your land), and increasingly easements for solar access (preventing one block from overshadowing another's panels).

Most utility easements come with build-over restrictions. You generally cannot put a permanent structure — slab, footing, masonry — within a defined "zone of influence" around the asset. Sydney Water, for example, publishes a 1-metre minimum horizontal clearance from pipes up to 300 mm diameter and a 300 mm vertical clearance below a slab; bigger pipes demand more, and trunk sewers or rising mains are typically refused outright. To build over or near an easement, you usually need a build-over application to the asset owner. That can require engineered footings, articulation joints, CCTV inspection of the pipe, or a Specialist Engineering Assessment — and it takes weeks to months and can add several thousand dollars or more to the project.

A few terms worth knowing. The dominant tenement benefits; the servient tenement is burdened. An easement in gross is held by a public authority rather than a benefiting parcel (most utility easements are of this type). The zone of influence is the soil-mechanics buffer around a pipe within which structures must be designed to support themselves rather than load the asset. A build-over application is the formal approval to place a structure within the easement or its zone of influence. A Section 73 Compliance Certificate (NSW) is Sydney Water's sign-off enabling registration of new lots.

Questions worth asking the seller (and your conveyancer):

  • Show me every easement on the lot — the exact width and location on the plan.
  • Where physically is the pipe or asset within the easement, and at what depth?
  • What is the pipe's diameter, material, age and condition — has anyone done a CCTV inspection recently?
  • What is the zone of influence, and how does it constrain my house footprint?
  • Can I build over part of the easement with the asset owner's approval — and what would that cost?
  • Is the asset a non-build-over class (rising main, trunk sewer)?
  • For a right of carriageway: who can use it, with what vehicles, and who maintains the surface?
  • Has any past build-over approval been granted on this lot?
  • Are there any unregistered but obvious services (gas, NBN, overhead power) crossing the land that aren't shown on title?

Who can help. A registered surveyor can locate the easement on the ground for $1,500–$5,000. A structural or civil engineer designs build-over compliant footings — typically $3,000–$15,000. In NSW, a Water Servicing Coordinator can manage the build-over application to Sydney Water, with fees varying by scope. Your conveyancer or solicitor reads the easement text in conjunction with the plan.

A useful sanity check before exchange: ask for service location diagrams from the relevant water authority (Sydney Water Tap In, Hunter Water, Yarra Valley Water, Urban Utilities, and equivalents elsewhere), and lodge a Before You Dig Australia enquiry (free, online at byda.com.au) to see every known underground service. The plan tells you what's registered; BYDA tells you what's actually there.

A single drainage easement diagonally across the buildable area can reduce land value substantially. A rear-corner easement on a large lot may have almost no impact. The same word — "easement" — covers both situations, which is why you read the plan, you locate the asset on the ground, and you ask the asset owner what build-over relief is available, before you decide what the lot is worth.

This article is general information only — a starting point for your own questions, not engineering, legal or financial advice. Easement law and build-over policies vary by state, territory and asset owner and are subject to change. Always engage a registered surveyor, civil or structural engineer, and licensed conveyancer or solicitor, and request from the seller the full text of every registered easement instrument plus current service location diagrams from the relevant utilities. Independent advice should be obtained before making any property decision.