Two survey crews can show up on the same job site for two different reasons. One marks where the work is supposed to go. The other records where the work actually ended up. Mixing up the two can cost a project time and money.
The Same Project, Two Very Different Surveying Moments
Construction staking happens before or during construction. A survey crew marks the ground with stakes, flags, or paint. Those marks show contractors where to build: the corner of a foundation, the edge of a curb, the center line of a pipe.
An as-built survey happens after. It records what got built, not what was planned. Once a slab is poured or a pipe is buried, a surveyor measures its real location and elevation.
Take a mixed-use project near Ballston. Before the crew pours a foundation wall, a surveyor stakes its corners and grade. Months later, once the wall is up, a separate survey confirms exactly where that wall sits and how tall it stands. Same project, two separate jobs, two separate purposes.
Proposed Coordinates vs. Field-Verified Conditions
Construction staking starts with the approved design: a set of plans with coordinates, elevations, and grades set by an engineer. The surveyor turns those numbers into physical points on the ground. Stakes, hubs, marks on pavement, offsets from a building line.
As-built surveying starts with what’s already there. The surveyor measures the actual position and elevation of selected finished work: a curb, a manhole, a retaining wall, an underground utility line. The output is a plan, or an updated set of plans, showing those measured locations.
One turns numbers into ground marks. The other turns ground conditions into numbers on a plan.
Where Each One Fits in an Arlington Construction Schedule
Staking usually happens in stages. Layout for grading and utilities comes early. Layout for foundations, walls, and paving comes as each phase starts. A single project might need several staking visits as it moves along.
As-built work usually happens later, once a phase is finished enough to check. A utility line gets as-built before it’s covered with soil. A parking lot gets as-built once the paving is done.
Finishing staking doesn’t mean a project no longer needs as-built information. Field conditions change during construction. Crews shift offsets, dig around utilities they find in the ground, or make small adjustments to fit real conditions. Arlington project specifications for public works commonly reference construction layout, control lines, grades, and elevations at one stage, and as-built civil engineering plans at another. Those are treated as separate stages, not one combined step.
When the Field Result Does Not Match the Approved Design
An as-built survey sometimes turns up a gap between what the plans show and what got built. A wall might sit a few inches off its planned line. A pipe invert might land at a different elevation than designed.
That gap gets flagged, not ignored. On Arlington projects, contractors are typically directed to notify the project officer when field conditions differ from approved plans. From there, the difference gets checked against the plans and project requirements. Depending on the cause, the fix might be a plan revision, a field correction, or an approved exception.
The as-built survey’s job stops at recording what’s there. Deciding what to do about a mismatch falls to the design and project team.
Choosing the Right Surveying Support for the Project Phase
A short way to sort it out:
- Need to mark where proposed work should go? That’s construction staking.
- Need to record where completed work actually landed? That’s an as-built survey.
- Working on a larger project with multiple phases? Both services often come into play at different points.
Not every Arlington project needs both. What’s required depends on the approved plans, the project type, the contract documents, and applicable Arlington County requirements. A property owner or contractor should check those specific requirements rather than assume either service applies.
Frequently Asked Questions
Can construction staking replace an as-built survey?
No. They serve different purposes. Staking helps establish the intended location of construction in the field. An as-built survey records relevant conditions after installation. Whether an as-built deliverable is required depends on the project requirements.
Is an as-built survey performed before or after construction staking?
They’re generally tied to different project stages. Staking supports construction placement. As-built fieldwork is generally performed after the relevant improvements have been installed or reached the stage that needs to be recorded.
What happens if the completed work differs from the construction layout?
The difference gets checked against the approved plans and project requirements. Depending on what caused it, it may need to be recorded, reviewed, or corrected by the responsible project authorities.
Does Arlington County require an as-built survey for every construction project?
Not necessarily. Requirements vary by project and approval type. Arlington County documents show that certain development projects require as-built civil engineering plans. That shouldn’t be generalized to every construction project in Arlington.
Who should perform construction layout and as-built surveying in Virginia?
Where professional land surveying services are required, that work should be performed by someone licensed to practice land surveying in Virginia. Arlington project specifications, for example, reference retaining a professional land surveyor licensed in Virginia for the required construction layout work.
