We do not publish prices. Every project is quoted against its own scope, and a number on a web page gets pulled into an estimate without the conditions that produced it.
What can be published is the structure of the cost, which is more useful anyway. If you know what moves the number, you can interrogate any proposal — including ours.
The seven drivers
1. Access
Usually the largest single variable and the one least visible in a bid.
- Can plant reach the work, and what size?
- Is there a route, or does one have to be built?
- Is there room to stage material and turn machines?
- Is the work under a structure, with limited headroom?
- Does material have to be double-handled to reach the site?
- Is access from land, from water, or both?
A site an excavator can drive to and a site requiring a temporary causeway are different projects with the same drawing.
2. Whether the work happens wet or dry
This frequently exceeds every other difference. A method requiring a dry working area brings a coffer dam or diversion, pumping, the permitting for that, and the schedule for building and removing it. See what dewatering really adds.
A method placed in flowing water avoids the entire package.
3. Stone supply
For bagged armor the fill is stone, so:
- How far is the source?
- Does it produce a suitable gradation, or does the material need processing?
- Haul distance and truck cycle time
- Whether it can supply at the rate the placement needs
For riprap the same question is sharper, because the material has to meet a specified armor gradation. See when local stone changes the economics.
4. Crew and plant days
Rate of placement times duration. The variables:
- Placement rate for the method
- Whether curing, cabling, or basket assembly follows placement
- Tidal or window constraints limiting workable hours
- Weather exposure
- Whether the site can run one crew or several
On a short in-water window, placement rate is not a preference. It is whether the job finishes. See in-water work windows.
5. Extent
The quantity is a design output, not a preference, and two proposals working from different assumptions about scour depth and footprint will price different jobs.
The protected area at a structure is larger than the structure — see bridge pier scour — and a proposal priced on the smaller area is cheaper because it is less work, not because it is better value.
6. Temporary works and site management
- Traffic management, particularly on a road or rail asset
- Environmental controls, silt curtains, turbidity monitoring
- Working platforms
- Site security and welfare
- Out-of-hours or possession working
7. What happens afterward
The recurring cost. Inspection regime, expected maintenance interval, and the likelihood of re-work after a design event. See lifecycle cost vs. first cost.
The costs that hide outside the construction budget
Three that are real and are usually somebody else’s line:
Service loss. A closed road, a berth out of service, a rail possession. Frequently larger than the construction cost, and almost never in the comparison.
Permitting and design. Consultant fees, surveys, hydraulic modelling, certifications, and the elapsed time. A method that requires a no-rise certification or an individual permit carries that. See permitting in-water erosion work.
Repeat repair. A site being fixed after every significant event is being paid for repeatedly. The count in your own maintenance records is the number that matters here.
How the drivers differ between systems
Not by claiming ours is cheapest, but structurally:
Manufactured or precast systems carry manufacture, curing, storage, and haul of finished heavy units before anything protects anything.
Riprap carries quarrying to a gradation and hauling heavy graded stone.
Cast-in-place concrete carries formwork, a cure, and usually dewatering.
Bagged armor carries the bags, the local fill stone, and the plant to lift and place. The heavy component does not travel far, and no dry working area is required.
Each of those profiles suits different sites. On a site with a local quarry, easy access, and a dry working area, riprap’s profile is very hard to beat — see when riprap is still the right choice.
The questions to put to any proposal
- Does this include dewatering or temporary works, and where?
- What plan extent is this priced on, and how was it determined?
- Is the filter layer included, and how is it specified?
- Where is the material coming from, and is haul included?
- How many site days, and does that fit the work window?
- What subgrade preparation is assumed?
- What is the maintenance expectation over twenty years?
- What is excluded?
How to compare unlike armor bids works through these in full.
Where to go next
- Lifecycle cost vs. first cost
- What dewatering really adds
- When local stone changes the economics
- Budgeting at concept stage
- What a quote includes
- The cost hub for the rest
Send the site conditions and access through the quote form and you get sizing, quantity, and lead time within one business day.