Trenching Services WA 2026 - Get Quotes

What Trenching Actually Covers

Trenching is the work of opening a narrow excavation, placing something in it and closing it back up so nobody knows it was there. The something is usually a pipe, a conduit or a cable, and the value of the job sits almost entirely in the parts nobody sees afterwards. Depth, bedding, backfill, compaction and the marker tape above the service all determine whether the run lasts thirty years or fails in the first winter. A trench judged only on how neat the surface looks has been judged on the wrong thing. What goes into the trench besides the service itself is the real measure of the work.

Bedding sand, marker tape and proper compaction are all invisible a week later and all decide how the run performs. The work divides cleanly between the digging and the connecting. An excavation contractor opens and reinstates the trench, and the licensed trade whose service is going in makes the connections, so a plumber lays and joins the pipe while an electrician terminates the cable. That boundary is normally settled at quoting stage and it is the source of most of the confusion in this category. Establish who is doing which part before you compare prices. Two quotes covering different halves of the job are not comparable at all.

Each side should confirm in writing what they expect the other to have done before they arrive. Most domestic trenches are short and shallow and the price is driven by circumstance more than by length. Thirty metres across open lawn in clean sand is a morning's work, and the same thirty metres crossing a paved alfresco, a driveway and a garden bed full of established roots is a different job entirely. The obstacles are what cost money.

Walking the actual route with the contractor is worth more than describing it over the phone. Have the route marked with paint or pegs before anyone quotes it. A route that avoids two obstacles is often worth a few extra metres of trench. Combining trenches is the single largest saving available. Where a property needs power to a shed, water to a garden tap and conduit for lighting, running them in one trench at the appropriate separations costs a fraction of three separate visits. It requires planning the work together instead of as it occurs to you.

The excavation and earthmoving page covers coordinating trenching with the rest of the earthworks on a site. Separation distances between services in a shared trench are specified, not improvised, and the installing trades will nominate them. Spare conduit laid while the trench is open is the cheapest thing on this page. An empty conduit with a draw wire in it, running from the house to the back of the block, costs very little to lay alongside whatever else is going in and saves an entire trench the next time something needs to go out there. Almost nobody does it and almost everybody wishes they had.

Get it done while the machine is still on site. Twenty five millimetre conduit, in an Iplex or Vinidex product, costs very little and covers most future needs. Larger conduit costs marginally more again and gives more options later. A trench also needs to be recorded before it disappears.

Photographs of the open trench with a tape measure visible, taken from a fixed reference point such as a corner of the house, are the only record you will ever have of where the service actually runs. Plans are approximate and memory is worse. Five minutes with a phone saves a great deal of guesswork later. Photograph both ends of the run as well as the middle.

Locating Services Before You Dig

The plans come first and they are free. The national referral service reached on 1100 sends the enquiry to the registered asset owners, who return plans showing their infrastructure in the vicinity, and those plans should be on site and read before any machine arrives. Turnaround is usually a couple of days, so the request goes in well before the work is booked. Digging without them is both reckless and, in a commercial context, a breach of ordinary practice. Lodging the enquiry early costs nothing and keeps it off the critical path.

Plans also expire, so an old set from a previous project should be refreshed. Keep the reference number, since the asset owners quote it in their responses. Plans show approximate positions, not surveyed ones. Assets move during construction, records are not always updated, and depths in particular are frequently different from what is recorded. A plan showing a cable somewhere along a verge is telling you to expect it in that general area, not to dig confidently a metre away from the marked line. Treat every plan as a warning.

It is not a guarantee. Depths in particular are the field most often wrong on an older plan. Potholing is how the approximate becomes exact. Hand digging or vacuum excavating down to expose the service confirms its actual position and depth before the machine goes anywhere near it, and it is standard practice on any run crossing a known asset.

Vacuum excavation uses compressed air or water and suction to remove soil without contacting the service, which is why it has become the preferred method around live assets. It is charged hourly and it is cheaper than a strike. Potholing is either inside the quoted price or charged separately, and you want that stated. Most contractors working near known assets will insist on it regardless. Private services are the ones that get cut and they appear on no plan anywhere.

Bore feeds, old irrigation mains, a cable to a shed installed by a previous owner, a pool return line and a gas line to a barbecue are all invisible to the referral service. What you know about your own property is genuinely useful information and worth telling the contractor. The garden bore installation and repairs page covers the bore lines that are so often forgotten. A sketch of what you know, handed over at quoting stage, is genuinely useful. Old plans from a previous owner are worth digging out of the house file. Hitting a service is expensive in every direction.

A cut Western Power cable is a safety incident before it is a cost, a severed Water Corporation main floods the site, a struck ATCO gas line evacuates the street, and a damaged Telstra or NBN Co cable can take out a neighbourhood. The asset owner charges for the repair, the contractor may carry liability and the work stops meanwhile. Every hour spent locating beforehand is repaid several times over. Insurance may cover some of it and the excess and the delay will still be yours. Contractors carrying proper cover will still want to avoid the strike entirely.

Repairing a struck fibre cable in particular can run into serious money. Underground services near a tree deserve their own thought. Roots follow services in sandy soil, so a trench that hits a root mass is often close to an old pipe, and the reverse is equally true. Cutting major roots also damages the tree and may breach a council tree protection requirement.

The tree lopping and arborist services page covers getting an arborist's view where a trench has to pass close to something significant. Trenching inside a tree protection zone may also need an arborist present on the day. Roots and services running together also make machine digging genuinely risky. Older Perth verges are the classic example, with a street tree and a supply line sharing the same metre of ground.

Depths, Cover and Bedding

Every service has a required depth of cover and those requirements exist for good reasons. Cover protects the service from surface loads, from future digging and from temperature, and the figures differ between electrical, water, sewer, gas and communications assets, with deeper cover required beneath driveways and trafficable areas than beneath a garden. The relevant Australian Standards set them out and the installing trade works to them. A trench dug to the wrong depth has to be dug again. The installing trade should confirm the depth in writing before the trench is dug. Different services in the same trench frequently need different depths.

Underground electrical work carries its own requirements and they are not negotiable. Cables run in conduit at the specified depth with marker tape above, and deeper cover applies where vehicles will cross, with the whole installation subject to the wiring rules and to inspection. An electrician will specify the trench they need before it is dug. The electrical services page covers engaging one, and the switchboard upgrade page covers the board end of a new submain. A submain to a shed needs the correct conduit type, not whatever is on the truck.

Water and sewer are plumbing work and the depths follow the plumbing standards. Sewer in particular is depth critical because it runs on a gradient and not a level, so the trench floor has to fall consistently from the fixture to the connection point, and getting that fall wrong produces a drain that blocks for the life of the building. Laser levels are how this is done properly. Eyesight is not.

The plumbing services page and the new home plumbing page cover the connections. A laser level on a sewer run is standard practice. The fall needs setting and checking before the trench is backfilled. Invert levels at each end should be recorded before backfilling. Gas has its own depth and its own rules, and only a licensed gas fitter may make the connections. The trench specification comes from the gas fitter and the work is certified on completion, with the conduit or sleeve requirements depending on what the line crosses.

This is not an area for approximation. The gas fitting and appliance installation page covers the licensed side of the work. Certification paperwork should come to you at the end of the job. Bedding is the layer that protects the service and it is routinely skipped. Clean sand placed beneath and around the pipe or conduit cushions it from rock and rubble in the backfill, prevents point loads that crack a pipe under traffic, and gives a consistent surface to lay on.

In limestone country that bedding matters far more, because backfilling a pipe straight onto broken rock will eventually damage it. Bedding sand should be named in the quote with a thickness against it. Fifty millimetres of bedding beneath and around the service is a common specification. Rubble backfilled straight onto a pipe will eventually find a weak point in it. On the coastal plain that risk rises sharply once limestone is in the spoil. Marker tape and draw wires are small items that pay off later.

Detectable warning tape laid above the service at the specified height tells the next person digging that something is below before their bucket finds it, and a draw wire in a spare conduit means a future cable can be pulled through without opening the ground. Both cost very little at the time. Neither can be added afterwards. Detectable tape is worth specifying over plain plastic, since a locator can find it.

Separation between services in a shared trench is specified, not left to the operator. Where power, water and communications share a trench, each has a required separation from the others, either by distance or by physical barrier, and stacking them at different levels is the usual arrangement. The installing trades will nominate the layout. What matters from your side is that the trench is dug wide and deep enough to accommodate it. Get the trench width nominated, because leaving it to whichever bucket is on the machine that day is not a specification. A trench cut too narrow makes the connections awkward and the bedding uneven.

Sand, Limestone and Clay

Perth's sand is easy to dig and awkward to trench. A chain trencher or a small excavator moves through clean sand quickly and cheaply, and the same sand will not hold a vertical face, so the walls slump into the trench as soon as it is open and any depth beyond about a metre becomes a genuine collapse risk. The answer is battering the sides back, shoring the trench or working quickly and not entering it. This is the defining characteristic of trenching on the coastal plain. A trench in sand is also far harder to keep to a clean line than one in clay. Working quickly and backfilling the same day is the usual approach on a domestic run.

Limestone stops a trencher completely. Where Tamala limestone or caprock sits in the route, the trench either goes through it with a rock saw or a hammer, or the route changes to avoid it, and the cost difference between sand and limestone is several times over. On the coastal plain the possibility should be priced in, not ignored. The rock breaking page covers how hammer and saw work is quoted and how a provisional rate should be written. Test holes along the route settle it before anyone quotes a rate per metre.

A route that runs around the rock instead of through it may cost less overall. The eastern suburbs generally trench more easily. The deep Bassendean sands run well below typical trench depths and the main complication is the same instability that affects all sand. Coffee rock, a cemented iron rich layer, appears in places and can be hard enough to slow a machine. It is far less common than the coastal limestone. Before assuming clean digging, find out whether coffee rock has turned up nearby.

Clay through the hills and parts of the South West behaves differently again. Clay holds a vertical face far better than sand, which makes a trench safer to work in and easier to keep tidy, and it is harder to dig and considerably harder when dry. It also swells and shrinks with moisture, so backfilled clay settles differently from backfilled sand. Contractors working the scarp price on that basis.

Contractors used to sand sometimes underestimate how much slower clay is to dig. Groundwater turns a routine trench into a pumping job. Near wetlands and through the low lying suburbs the groundwater is not far down, most obviously in the wet months, and a trench that reaches it refills as quickly as the bucket empties it. Dewatering with a pump adds time and cost, and a trench standing in water is unstable as well as unpleasant. Where the route is known to be wet, doing the work in late summer is worth considering. A pump running all day is a line item, not an inconvenience.

Dewatering is either included or excluded, and the quote should say. Winter trenching in a low lying suburb is harder work than the same job in March. Ground conditions also determine what the spoil is worth. Clean sand from a trench is reusable as backfill and often as bedding, broken limestone is not suitable against a pipe, and clay is poor backfill in a trafficked area.

The material coming out decides how much material has to come in. That balance should appear in the quote instead of surfacing as a truck invoice later. Imported fill is either allowed for or assumed unnecessary, and that assumption belongs on the page. Sand is cheap and the cartage is not, so the number moves with the load count.

Trenches by Service Type

Stormwater trenches are the most common on a Perth block, since roof and surface water has to soak away on the lot instead of running to the street. Downpipes connect to a pipe network running to soakwells, the trench falls towards the wells, and the pipe is bedded and backfilled so it does not deform under a driveway. The soakwell installation page covers the wells themselves, and the stormwater drainage plumbing page covers the licensed side of the pipework. The fall to the wells needs setting with a level, and eyesight does not count. A stormwater line that ponds will eventually silt up and block. Downpipe connections sit with either the trenching contractor or the plumber, so settle it.

Every downpipe on the house should be connected, not most of them. Subsoil drainage is a different trench for a different problem. Where the problem is groundwater instead of surface water, a slotted pipe is laid in aggregate wrapped in geotextile so water can enter along the length of the run, and the trench detail matters more than it does for a solid pipe. Getting the wrap and the aggregate right is what stops it silting up. The french drain and subsoil drainage page covers the construction.

Geotextile wrapped the wrong way around is a common and invisible defect. Reticulation mains are the shallowest trenches most properties will see and they are frequently underestimated. A retic main runs from the source to the valve boxes and the lateral lines run on from there, and the trench has to be deep enough that a garden fork will not find it and a lawn aerator will not cut it. Running the mains while a machine is on site for other work is far cheaper than a dedicated visit. The irrigation and garden watering systems page covers the system design. Running the mains deeper than the laterals is worth doing while the trench is open.

A main crushed by a lawn aerator is a repair nobody enjoys finding. Power runs to sheds, studios, pools and granny flats are one of the most common trenching enquiries. The trench specification comes from the electrician, the conduit and cable size come from the load and the distance, and the depth increases where the run crosses a driveway. Voltage drop over a long run frequently means a larger cable than owners expect.

The power point installation page and the outdoor lighting installation page cover what usually sits at the far end. Get the conduit size from the electrician before the trench width is decided. A long run to a rear studio frequently needs a larger cable than the load alone suggests. Water and sewer trenches on a new dwelling are set out from the connection point, not from the house. The position of the sewer junction determines where the drainage can run and sometimes influences where the building can sit, and it needs establishing early, because discovering it during construction is expensive.

On an older property the existing connection may be in an inconvenient place. The blocked drains page and the pipe relining and drain repairs page cover remedial work on existing lines. The junction position is recorded and can usually be confirmed before work starts. An inconvenient junction position can sometimes be relocated, at a cost. The plumber should confirm it before the trench route is finalised. Verge and crossover trenching brings the local government into it.

Any work in the road reserve generally needs council permission, often a permit and a bond, and work affecting a footpath or carriageway requires proper pedestrian and traffic management, not a witches hat. Anything touching a Main Roads Western Australia road brings a further set of conditions on top of the council's. Contractors who do this regularly will describe the process without being asked. A bond held against reinstatement is common and it is worth knowing who is carrying it. The permit fee and the bond either sit inside the quoted figure or they do not.

Directional boring avoids the trench entirely where the surface cannot be disturbed. A bore rig drills a path underground between two small pits, pulling the conduit through behind it, and it is the standard answer for crossing a driveway, a mature tree's root zone, a paved courtyard or a road. It costs more per metre than open trenching and it saves the reinstatement entirely. On a finished landscape it is frequently the cheaper option overall. Bore pits are small and they still need somewhere to sit at each end. Wherever a crossing is involved, get a bore price alongside the trench price.

Collapse, Shoring and Safety

Trench collapse is the risk that kills people in this trade and sand makes it worse. A cubic metre of soil weighs well over a tonne, a collapse happens without warning, and a person buried to the chest cannot self rescue and cannot breathe against the pressure. Western Australian coastal sand offers no cohesion at all, so a trench that looks stable in the morning can slump by afternoon. This is not a theoretical concern.

Nobody should be standing in an unsupported trench in coastal sand, whatever the depth looks like. The controls are well established and they are not optional on a workplace. Excavations beyond a defined depth require the walls to be battered back, benched or supported with shoring or a trench shield, and deeper excavation work is treated as high risk construction work requiring a documented safe work method statement. WorkSafe WA is the regulator that enforces all of this on a site. A contractor who describes their approach to trench support is a contractor who has thought about it. On deeper runs, find out what support method the contractor uses.

A trench shield is standard hire equipment, not an exotic request. Battering the sides back is often simpler than shoring on an open block. Spoil placement matters more than people realise. Material stacked at the edge of a trench loads the wall it is sitting on and is a common contributing factor in collapses, which is why spoil is set back from the edge instead of piled beside it. Machines and vehicles operating close to an open trench have the same effect.

Watching where the spoil goes is a reasonable way to read how a crew works. Spoil set back a metre from the edge is the usual practice. Entry into a trench should be deliberate. Casual entry is how people are hurt.

Most domestic service trenches are shallow enough that nobody needs to get in, and where entry is required for a connection, the support, the access and the escape route are all established first. Somebody jumping into a chest deep trench in sand to make a joint is taking a serious risk for a five minute task. Good crews plan the work so it is not necessary. Planning the joint positions so they fall outside the deep section is part of that. Planning the work so nobody enters the trench at all is better again. Open trenches on a residential property are also a hazard to everyone else.

Children, pets, delivery drivers and the owner walking out at dusk are all at risk from an unfenced trench, and leaving one open overnight without barriers is an obvious liability. Barriers, covers or backfilling before the end of the day are all reasonable. There should be a clear answer on what happens to the trench overnight. A sheet of ply and a witches hat is not a barrier. Live services in an open trench carry their own risk.

Where a trench exposes an existing cable or a gas line, the exposure needs protecting and the service owner may need to be involved. Nobody should be working around an exposed live cable on the assumption it will be fine. This is another reason potholing and locating are worth doing properly at the start. The asset owner will usually attend where their equipment is exposed. Somebody has to notify the asset owner if something is exposed, and it should be named.

Backfill, Compaction and Reinstatement

Backfill decides whether the trench line stays invisible or reappears as a sunken stripe across the lawn. Material is returned in layers and compacted as it goes, not tipped in and left, because loose backfill in sand settles for months afterwards and the surface drops. In a trafficked area that settlement cracks paving and creates a trip hazard. Compaction should be named in the quote along with the method.

Compacting in layers of around three hundred millimetres is normal practice. The specification assumes a plate compactor, not a boot. The material returned matters as much as the method. Clean sand compacts well and is the usual backfill on the coastal plain, while broken limestone, rubble and organic material are all poor choices around a service and against a pipe. Where the spoil coming out is unsuitable, clean fill has to come in and that is a cost.

It should appear in the quote instead of emerging on the day. Spoil is either suitable for reuse or fill is being brought in, and that determines a real cost. Organic material left in the backfill will rot and leave a void behind it. Settlement is almost inevitable to some degree and it is manageable. Even well compacted backfill in sand will move a little as it takes up moisture through the first winter, which is why leaving the surface slightly proud of the surrounding level is common practice. A contractor who mentions this in advance is being straight with you.

Topping up the line the following spring is a small job, not a defect. A slight crown over the trench line is deliberate, not untidy. Reinstating lawn is straightforward and reinstating paving is not. Pavers lifted carefully before the trench is dug can be relaid afterwards, and pavers broken by a machine cannot, so the approach to a paved route needs deciding before anything starts. Matching an old paver is frequently impossible, which is another argument for boring underneath instead of trenching through.

The paving and driveway installation page covers the reinstatement work. Lifting pavers carefully by hand takes time and it is time well spent. Establish whether the contractor will lift and relay them or whether a paver is needed. Ordering a few spare pavers at the outset is cheap insurance. Concrete reinstatement is its own trade and its own finish. A trench cut across a concrete driveway leaves a joint that will always be visible, the new concrete will not match the old in colour, and a saw cut edge reinstates far better than a broken one.

Where appearance matters, boring under the driveway avoids the question entirely. The concreting services page covers the repair, and the driveway excavation page covers work where the driveway is being replaced anyway. A saw cut also gives a straight edge for the new concrete to key against. Verge reinstatement is usually a council requirement with a standard attached.

The local government will specify how the verge is to be left, whether topsoil and turf are required, and may hold a bond until it is inspected. Leaving a verge rough after a service trench is how bonds get forfeited. Confirm who is responsible for the reinstatement and whether the bond is in the quote. Check whether the council's standard specifies turf or seed. Bonds are refunded after inspection, not automatically. Record what went where before the trench closes.

A photograph with a tape measure and a fixed reference, plus a note of the depth, takes a minute and becomes genuinely valuable the next time anybody digs on the property. Marker tape protects the next contractor and your photograph protects you. The landscaping page covers the garden work that often follows a trench across a finished space. A note kept with the house documents outlives everyone's memory of the job.

Costs in Detail

Trenching in clean sand runs $22 to $55 a linear metre for a typical domestic service trench, covering the excavation and basic backfill. The range reflects depth, width, access for a machine and whether the route is clear. Short runs carry a minimum charge because mobilising the machine costs the same regardless of length. Below about ten metres most contractors quote a lump sum instead of a rate.

Get the minimum charge before you start comparing per metre rates. Minimum charges also apply to the smallest jobs regardless of the rate quoted. Trenching through limestone runs $90 to $260 a metre, which is the single largest variable on the coastal plain. Where the run is long enough to justify mobilising a rock saw, the rate per metre usually beats hammer work and leaves a better trench. For a short section a hammer is the practical answer. Have the contractor compare both for your length.

A saw also produces far less spoil than a hammer over the same length. Machine and operator hourly rates of $110 to $220 apply where the work is not easily measured by the metre, such as a trench with multiple obstacles, unknown services along the route or a lot of hand work around existing assets. Hand trenching in tight access runs $55 to $130 a metre and is used where a machine cannot reach or where services make machine digging unsafe. Vacuum excavation for potholing is charged hourly and is worth every dollar around live assets. Hand digging around a known asset is cheaper than repairing one.

The traffic management requirement needs confirming with the council first. Directional boring under a driveway, a tree or a paved area runs $450 to $1,800 per crossing depending on length, depth and ground conditions. Set against breaking and reinstating a concrete driveway, it is frequently the cheaper option as well as the tidier one. It needs a pit at each end and clear access for the rig. Have it priced as an alternative wherever a trench would cross something you care about. It also leaves the surface entirely undisturbed, which matters on finished landscaping.

Bedding sand and proper backfill run $12 to $35 a metre where they are itemised, and imported clean fill adds to that where the spoil is unsuitable. Paving reinstatement runs $65 to $160 a square metre depending on the paver and whether they can be reused. Traffic management for verge or road reserve work runs $600 to $2,400 a day depending on the road and the requirements. None of these are optional extras where they apply.

Imported fill is priced by the cubic metre delivered. A fill figure is either an allowance or a fixed quantity, and those behave very differently. Regional Western Australia prices around travel and machine availability. Contractors working out of Bunbury, Albany, Geraldton and Kalgoorlie charge much what metropolitan crews do within their own areas, and mobilisation is the line that moves on a country job.

Specialist plant such as a rock saw or a boring rig may not be locally available at all, which can mean waiting or paying to bring it in. Booking ahead matters more in those areas than negotiating. Specialist plant may need booking weeks ahead in regional areas. Where a rock saw has to come from Perth, the mobilisation can exceed the trenching itself.

What to Look Out For

Never let anyone dig without the service plans on site. The referral service is free, the turnaround is a couple of days and the plans are the minimum standard of care on any excavation. A contractor who suggests going ahead without them is telling you how they approach risk generally. See the plans yourself, and find out what potholing is planned along the route. A contractor who orders the plans as a matter of course is the one to engage.

Ordering plans is free and there is no reason to skip it. Watch for a quote that covers digging but not bedding, backfill or reinstatement. Those three are where the value of a trench sits, and a rate that looks sharp until the reinstatement is quoted separately is not a sharp rate. Each one should be named. A trench left as a mound of spoil across a lawn is a job half finished. Reinstatement needs describing in the quote, because the word on its own means nothing.

A quote that stops at the spoil heap has priced half a job. Take the depth question seriously instead of accepting whatever the machine happens to dig. Cover requirements exist to protect the service and they differ between electrical, water, sewer and gas, with deeper cover beneath driveways. A trench dug too shallow has to be dug again, and one discovered later during another job is a hazard.

The installing trade should specify the trench before it is opened. Marker tape at the specified height above the service is part of the same requirement. A shallow trench also becomes a hazard for the next person who digs there. Be careful about trenching close to a tree without advice. Cutting through the root plate of an established tree can destabilise it and can breach a council tree protection requirement, and the damage does not show for a season or two. Boring under the root zone costs more and avoids both problems.

Where the tree is significant, get an arborist's view first. A tree protection zone is defined by the trunk diameter, not by the canopy. Check what happens to an open trench overnight. Barriers, covers or same day backfilling are all reasonable and leaving an unfenced trench open on a residential property is not. Children and pets are the obvious concern and delivery drivers are the one nobody thinks of.

Raise it before work starts, not at six in the evening. Barriers left overnight should be the sort that cannot be moved by a child. A cover rated to take a step is better than a barrier around the hole. One last thing, lay a spare conduit while the ground is open.

An empty conduit with a draw wire costs very little alongside work already happening and saves an entire trench the next time something needs to run to the back of the block. Owners who have done it once never skip it again. Have it priced as an option on every trenching quote you get. Run it to wherever you might one day want power, water or data.

How to Get Comparable Quotes

Describe the route, not just the destination. Where the trench starts and finishes, roughly how long it is, what it crosses along the way including lawn, garden beds, paving, a driveway, a verge or a tree, what service is going in, who is supplying and connecting it, and whether the plans have been ordered. Photographs along the route, and one of each obstacle, help enormously. Contractors quoting from that price the actual trench. Note precisely where the trench has to start and finish, because approximately is not a set of instructions.

Marking the route on the ground before quoting removes most ambiguity. Say who is doing the connecting. A trench for an electrician is a different document from a trench for a plumber, and the installing trade usually specifies the depth, the width and the bedding. Where you have already engaged them, pass on their requirements with the enquiry. Where you have not, the contractor may be able to recommend someone who works with them regularly. Passing on the installing trade's specification avoids two rounds of quoting.

Put the same written questions to each contractor. The rate and what it includes, the assumed ground condition and the provisional rate if rock appears, bedding sand and backfill, compaction method, marker tape and spare conduit, reinstatement of lawn, paving or concrete, who orders the service plans and does the potholing, overnight barriers, verge permits and traffic management if relevant, and their insurance position. Written answers make three numbers comparable. Every contractor should name their exclusions as plainly as their inclusions.

A quote listing its exclusions plainly is usually the most honest one received. A written scope also protects the contractor from being asked for extras later. Get boring priced wherever a trench would cross something you care about. Driveways, established paving, mature trees and finished landscaping are all candidates, and the comparison between trenching and boring is often much closer than owners expect once reinstatement is counted. Getting both figures lets you decide on evidence.

A contractor who offers the comparison unprompted is being genuinely helpful. The difference narrows further once the risk of cracking old paving is counted. Combine everything that needs a trench into one visit. Power, water, gas, stormwater, retic mains and lighting conduit can frequently share a route at the required separations, and the marginal cost of an extra conduit in an open trench is small next to a second mobilisation.

The excavation page covers the wider earthworks that can be bundled in. Planning the whole property's underground services once is the biggest saving available in this category. Laying spare conduit to two or three destinations at once costs very little extra. A draw wire left in an empty conduit is the cheapest future proofing available on a property.