Written and reviewed by the Kuesel field operations & estimating team
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Kuesel is a family-owned site work and utility contractor based in O'Fallon, MO, building sites across St. Louis since 1963.
Developers often ask for a cost per acre for sitework. We don't give one, because two sites of the same size can differ several times over depending on the ground, the grades and the utilities. What we can do is explain what actually moves the number, so you know which questions to answer first and which design decisions still have room to change.
This guide lists the main drivers in roughly the order they tend to matter on St. Louis-area commercial and industrial sites. There are no dollar figures here on purpose: prices change, and every site is different.
1. Earthwork balance
The single biggest swing on most sites is whether the dirt stays on site. Moving material from a cut to a fill a few hundred feet away is far cheaper than loading it into trucks and hauling it off, or buying and hauling fill in. Pad elevations, parking grades and the location of detention all change the balance.
The balance can be adjusted during design. That is why we model grading early with AGTEK during preconstruction; our cut and fill guide goes into how.
See how we approach excavation, grading and earthwork on commercial and industrial sites.
2. Rock
Rock that has to be broken with a hammer or otherwise removed is slower and more expensive than common excavation, and it is often found in utility trenches rather than mass grading. Refusal depths in the borings, compared with the deepest cuts and pipe inverts, tell you where the risk sits. See rock and poor soils for how to carry that risk in a budget.
3. Poor soils
Wet, soft, or high-plasticity clays may not support pavement or building pads as they are. The fix is usually undercutting and replacing the soil, or treating it in place with lime or cement. Which is cheaper depends on the area, depth, and haul distances, so both should be priced. Our soil stabilization team prices both on request.
For poor subgrade, compare undercut with soil stabilization services.
4. Stormwater and detention
Detention basins, bioretention, underground storage and outfall work can take land and money. The requirements depend on the reviewing agency and the site. Getting a realistic footprint for detention onto the concept plan early avoids redesign later. More in our stormwater guide.
5. Utilities: length and depth
Utility cost follows length, depth and conditions. A sewer that needs a long off-site extension, a deep trench, or a crossing under a road changes the budget fast. Deeper trenches need more protection, and rock in a trench costs more than rock in a mass cut. Confirm where water and sewer are and how deep the sewer is before committing to a layout. Our water and sewer crews install site utilities across the region.
6. Retaining walls
On sloping sites, walls let you hold pad elevations and parking without pushing grades into neighboring land. They are also a major cost line. Sometimes adjusting a pad elevation or a parking layout removes the need for a wall. Sometimes a wall is cheaper than hauling dirt. Both options should be on the table during design.
7. Phasing and mobilizations
Every time crews and equipment leave and come back, there is a cost. A project that grades the whole site once is usually more efficient than one that grades in many small phases. Phasing is often needed for financing or leasing, so the goal is to phase on purpose: group work so each return trip is worth it, and plan stockpiles and drainage between phases.
8. Season and weather
Clay soils that grade well in a dry summer can turn to mud in a wet spring. Starting mass grading in a wet season can mean more drying, more stabilization, or lost days. Erosion control maintenance also goes up with rain. A schedule that puts mass grading in the drier months, where possible, is one of the cheapest risk reductions available.
9. Access, demolition and existing conditions
Tight access, haul restrictions, existing buildings or pavement, and old fill all add cost. Some can be found with a site walk and a review of historical aerials. Demolition debris can sometimes be crushed and reused on site, which affects both the demolition and the import line.
Where to start
The drivers that matter most on your site depend on what's under it and what's being built on it. Our Early Site Budget reviews your survey, concept plan and geotech, then explains which drivers apply and what can still change. We price sites across the region, from St. Louis to St. Peters and Belleville.
Use our due-diligence checklist to collect the information, and browse the resources library for related guides.
Questions
- Why won't Kuesel give a cost per acre for sitework?
- Because it would be misleading. Earthwork balance, rock, soils, utilities and stormwater vary so much between sites that a per-acre number can be off by a wide margin. A preliminary budget built from your survey and geotech is far more useful.
- Which cost driver should I check first?
- Usually the earthwork balance and the geotech findings, since they affect export, import, and subgrade preparation across the whole site.
- Can design changes really reduce site cost?
- Often, yes. Adjusting pad elevations, parking grades, detention location or a utility route during design can reduce export, walls, or trench depth. Those changes are hard to make once plans are bid.
- Do you include dollar figures in this guide?
- No. Prices change and every site is different, so this guide covers the decisions and conditions that move cost. For numbers on your site, request an Early Site Budget.
This guide is general information from a site contractor, not engineering or legal advice. Your engineers and the reviewing agencies set the requirements for your project.