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Sitework & Earthworkaka: site prepaka: site clearingaka: mobilization

Site Preparation

In Plain English

All the preliminary work done to get a construction site ready — clearing, demolishing, and preparing the ground.

Definition

All preliminary work required to ready a site for construction, including land clearing, demolition of existing structures, grubbing of vegetation, removal of unsuitable soils, and establishment of temporary site infrastructure. Site preparation sets the stage for all subsequent earthwork and construction activities. Proper site preparation prevents problems with soil stability and drainage throughout construction.

Why It Matters in Bidding

Site preparation is one of the riskiest line items to estimate because much of it is hidden — unsuitable soils, buried debris, or undocumented utilities can balloon costs well beyond the bid, making subsurface assumptions a major source of contingency and change orders. Bidders rely on the geotechnical report and existing-conditions surveys to price clearing, demolition, and soil removal, and they often carry unit-price allowances so unexpected quantities can be reconciled fairly. Done correctly it protects the entire project schedule, since drainage and soil-stability problems left unaddressed resurface throughout construction.

Example

After clearing the site the contractor discovered an old buried foundation not shown on the survey, triggering a change order for additional demolition and unsuitable-soil removal beyond the site-preparation allowance in the original bid.

Related Terms

Land ClearingEarthworkGradingTopsoil

Frequently Asked Questions

Common items are land clearing and grubbing of vegetation, demolition of existing structures, stripping and stockpiling topsoil, removal of unsuitable soils, rough grading, and installing temporary infrastructure like erosion controls, construction entrances, and site fencing. Exact inclusions depend on the contract scope, so estimators check whether utilities, dewatering, or environmental remediation fall inside this line or a separate package.
They study the geotechnical report and existing-conditions surveys, then carry contingency or unit-price allowances for items like undocumented utilities, rock, or unsuitable soils that may differ from assumptions. Many contracts include a differing-site-conditions clause that lets the contractor recover added cost when actual conditions vary materially, shifting some hidden-condition risk back to the owner.
Mobilization covers moving equipment, crews, and temporary facilities onto the site and setting up to work. Site preparation is the physical work of readying the ground itself, including clearing, demolition, and soil correction. Although the two overlap on the schedule and are sometimes bundled, treating them as separate line items gives cleaner cost tracking and avoids front-loading.

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