Construction Site Prep Cost Calculator

Site prep ranges $1.50–8.00 per sq ft depending on terrain, demolition, and utilities.

Lot sq ft

Clearing $/sf

Grading $/sf

Erosion control

Demolition cost

Contingency %

Total site prep

$31,320

Blended $/sf

Contingency

$5,220

How the math works

Base = lot × (clearing + grading) + erosion + demo. Total = base × (1 + contingency).

12,000 × ($0.85 + $0.95) = $21.6k + $4.5k = $26.1k × 1.20 = $31.3k site prep.

How to Use

Enter lot sq ft.
Enter clearing $/sf.
Enter grading $/sf.
Enter erosion control.
Enter demolition cost.
Enter contingency %.
Read total site prep.

Frequently Asked Questions

Site prep components?

Clearing/grubbing: $0.20–1.50/sf. Rough grading: $0.40–1.20/sf. Fine grading: $0.30–0.80/sf. Demolition (existing structure): $4–16/sf of structure. Erosion control (silt fence, BMP): $0.30–0.80/sf. Tree removal: $300–2,500 per tree. Stump removal: $200–800 per stump. Hazardous waste, contaminated soil: $30–200/cy. Dewatering pumps: $200–800/day. Add 15–25% contingency on greenfield, 25–40% on infill brownfield.

How does this impact project budget?

Construction budgets layer hard costs (50–65%), soft costs (15–25%), financing (5–10%), contingency (5–10%), and developer fee (3–5%). Schedule risk often equals or exceeds cost risk — every month delay carries carry cost (interest, real estate tax, insurance, opportunity cost) of 0.5–1.5% of project budget. This calculator quantifies one cost component.

Owner-controlled vs GMP vs CM-at-risk?

Lump sum/GMP: contractor takes risk above guaranteed maximum price, owner pays for change orders. CM-at-risk: open book, fee + GMP, more transparent. Construction management: agent for owner, GC subcontracted directly. Design-build: single accountability, faster but less price competition. Match delivery method to project complexity and owner sophistication.

Schedule and cost contingency?

Standard contingency: 10% of hard cost for entitlement, 5–8% for construction. Schedule contingency: 60–90 days buffer past target completion. Force majeure provisions: weather, material lead time, labor strike, permit delay. Track via critical path method (CPM) schedule. Major lender draws contingent on schedule + cost variance to budget remaining within 5%.