Ask what a fibre build costs and the honest answer is 'it depends' — but it depends on a fairly predictable set of things. Knowing which ones move the number most is how you build a network that stacks up commercially. Here's where the money goes.
Civils is the big one
On most underground builds, civil engineering — excavation, sub-duct, chambers and reinstatement — is the largest single cost. It's labour- and plant-heavy, weather-exposed and tightly regulated. Anything that reduces the metres you have to dig has an outsized effect on the total.
Reusing infrastructure changes the maths
This is why PIA — running fibre through Openreach's existing ducts and poles — and aerial builds matter so much. Reuse existing routes and you avoid a large share of the civils. The trade-off is survey and administration effort, but done properly it's usually money well saved.
Materials and design efficiency
Cable, closures, chambers and cabinets add up, but the bigger lever is design. A tight low-level design that minimises fibre runs and splice counts, and a bill of materials that matches the build, avoids both over-ordering and mid-build surprises.
Splicing, testing and labour
Skilled splicing and testing is a real cost, and rightly so — it's the quality that keeps the network alive. Where money leaks is rework: a splice that fails testing, or a fibre that has to be re-pulled, costs far more the second time.
The hidden costs: permits, reinstatement and rework
The line items that catch people out are rarely the obvious ones. Permit and traffic-management costs, reinstatement to the highway authority's standard, and remedial works for anything that fails inspection can quietly swell a budget — especially if the early stages were rushed.
How to build cost out early
The cheapest savings are the ones designed in before a spade goes in the ground: a thorough survey, a route that reuses infrastructure where it can, an efficient design, and permits secured ahead of the gangs. Spend time at the front and the back looks after itself.
Want a build costed realistically, with the savings found early? Get in touch.