How much does directional drilling cost? It is the question we get asked more than any other, and the honest answer is that it depends. HDD pricing is specific to each project, driven by bore length, pipe diameter, ground conditions and the size of rig the job needs.
This guide explains what actually drives the price of an HDD project in the UK, how it compares to open-cut once you count the full cost, and how to get an accurate quote.
New to the method? Start with What Is Horizontal Directional Drilling?
What Does Directional Drilling Cost Per Metre?
There is no single per-metre rate for HDD. The same bore length can cost very different amounts depending on the conditions, so a flat figure would only mislead you.
As a rough guide, short small-diameter utility crossings in straightforward ground sit at the lower end. Long bores, large diameters, difficult ground and tight urban sites cost more. The rate per metre also tends to drop as a bore gets longer, because the fixed costs of mobilising, setting up and managing traffic are spread over more pipe.
Because every bore is different, the only number worth having is a proper quote for your job. The factors below are what we weigh up when we price one.
What Drives the Price
Bore Length and Diameter
The two biggest factors. A longer bore means more time, more fluid and more reaming passes. A larger diameter needs a bigger rig, more fluid, larger tooling and higher pull forces. A short, small-diameter road crossing is a different job entirely to a long, large-diameter crossing.
Ground Conditions
Ground type drives drilling speed and tool wear. Clay and sand drill easily. Gravel and cobbles slow things down and make steering harder. Rock needs specialist tooling and is much slower, and more expensive, than soil.
A ground investigation before we start lets us plan the right kit and parameters. Without one, the contractor carries the risk of the unknown, and that risk shows up in the price.
Pipe Material
PE (polyethylene) is the usual choice for HDD because it is flexible, light and can be fusion welded into long continuous strings. It is also relatively inexpensive. Ductile iron, steel and GRP are heavier, stiffer and dearer to supply and handle, and they need a larger bore to pull through.
Site Access and Location
Urban sites with restricted access, limited working room, traffic management and noise limits cost more than open rural sites. Working next to live utilities, inside the highway or near sensitive neighbours all add cost through the extra care and compliance involved.
Rig Size
Compact rigs are cheaper to mobilise and run than larger machines. The right rig is set by the bore length, diameter and ground. Too big wastes money. Too small risks a failed bore.
Surveys and Permits
Before drilling under a road or near existing services, utility surveys and trial holes may be needed to pin down what is already in the ground. Permits may be required from the highway authority, Network Rail, the Environment Agency or the Canal and River Trust, depending on the crossing. These are real costs on the job.
HDD Cost vs Open-Cut Trenching
Comparing HDD and open-cut on the per-metre rate alone is misleading. Open-cut can look cheaper for the length of pipe laid, but the total cost includes plenty that HDD cuts out or shrinks.
| Cost element | HDD | Open-cut |
|---|---|---|
| Excavation | Two small pits | Full-length trench |
| Reinstatement | Two pit areas | Full trench reinstatement to highway spec |
| Traffic management | Usually not required | Road closure or traffic lights for the duration |
| Programme | Days | Weeks |
| Disruption | Minimal | Significant (supply interruptions, access restrictions) |
| Spoil disposal | Fluid and cuttings (small volume) | Large volumes of excavated material |
For crossings under roads, rivers and railways, HDD almost always wins on total cost, because the reinstatement and traffic management of open-cut dominate the budget. Two of our own jobs show how much that matters.
- Industrial yard, gravity drainage. We installed around 66 m of 110 mm MDPE gravity drainage beneath a busy concrete yard in a single day, without cutting or excavating the slab. Site traffic kept running the whole time, which avoided the reinstatement bill and the downtime that open-cut would have forced. Read the case study.
- Outlet pipe through residential gardens. We steered an 80 m bore of 63 mm PE through eight gardens and kept the pub car park fully open, finishing in two days with no surface disruption. Read the case study.
For straight runs in open ground with no obstacles, open-cut can still come out cheaper if reinstatement is simple, such as backfilling a trench on a greenfield site. We will tell you when that is the case.
HDD Cost for Water Mains
Water mains are one of the clearest cases for HDD on total cost, because the reinstatement, lane rental and supply-interruption costs of open-cut road works run so high.
For the detail, read HDD for Water Main Replacement: How It Works.
How to Get an Accurate Quote
To price your job properly, we need:
- Start and end points of the bore, or a plan showing the route.
- Pipe details: material, diameter, length.
- Ground conditions: any ground investigation data, or at least the geology you would expect from BGS mapping.
- Existing utility records along and near the route.
- Site access: any limits on working hours, access or compound space.
- Programme: when the bore needs to be finished.
The more you can tell us upfront, the tighter the quote. If you are still at an early stage, we can give a budget figure from the outline and firm it up as the design develops.
Request a quote, or contact us for a free assessment.
Is HDD Worth the Cost?
For most projects, yes. The real question is not whether HDD costs more per metre than open-cut. It is whether the whole job comes out better. HDD gives you:
- A faster finish. A crossing that takes a few days by HDD can take weeks by open-cut.
- Lower reinstatement costs. Two small pits instead of a full trench.
- No traffic management bill. No road closures, no temporary lights, no lane rental.
- Less disruption. Fewer complaints, shorter supply interruptions, less upheaval for businesses and residents.
- A lighter environmental footprint. Less excavation, less spoil, less disturbance.
For utility providers working at scale, those programme and reinstatement savings add up fast across a year of installations. For a one-off project, the call is simple: get both prices, compare the total cost, and factor in the time and disruption.
