Case Study

Field Coordination: When the Building Doesn't Match the Drawings

How a contractor used a 3D laser scan to document existing conditions, measure a deviation from the design, and resolve it before it turned into rework.

Project Overview

Partway into a Chicago renovation, the general contractor suspected the existing structure did not match the design drawings. Trusting the discrepancy to tape measures and field notes risked a dispute later, so the contractor brought in Laser Scan Chicago to document the actual conditions and measure exactly how far reality differed from the plan.

Point cloud overlaid against the design BIM model to measure field deviation: Laser Scan Chicago
Point cloud overlaid against the design model. The gap between as-designed and as-built, measured rather than argued.

The Challenge

  • The design assumed conditions that the field appeared to contradict
  • An undocumented deviation discovered late is expensive: rework, schedule slip, and finger-pointing
  • The contractor needed an objective, dimensioned record, not an estimate, to coordinate the fix and account for it

The Approach

Laser Scan Chicago scanned the area in question with FARO Focus equipment and registered the point cloud, then overlaid it against the design model. That overlay turned a suspicion into a measured fact: the precise location and magnitude of the deviation, documented in three dimensions.

Deliverables

  • Registered point cloud of the existing conditions
  • Scan-versus-design overlay quantifying the deviation
  • An objective, dimensioned as-built record of the area

Results

With the deviation documented to the millimeter, the contractor coordinated the fix against real conditions instead of guessing, and had a precise record to support the change order. The conversation moved from "it looks off" to "here is exactly what is built and by how much," which is a far stronger position for everyone at the table. The scan paid for itself many times over against the cost of discovering the same problem after the work was already in place.

Measured Deviation documented, not estimated
On record Objective basis for the change order
Before, not after Caught at documentation, not in finished work

Have a Condition You Need to Pin Down?

Laser Scan Chicago gives general contractors, architects, and owners an independent, dimensioned record of exactly what is built. Your scan is yours: an objective record to coordinate from and rely on. As a local Chicago team, we can be on site quickly when the question can't wait. Contact us to discuss your project.