An as-built survey records what got built. Not what was planned. It measures the finished project. Then it compares those numbers to the design drawings. In Maryland, this survey becomes the last measured record once a job wraps up. It shows owners, engineers, contractors, and reviewing agencies where things actually sit on the ground.
The Finished Location of New Improvements
Plans show where a building, driveway, or wall should go. Crews work from those plans. But field conditions shift things. A footing gets poured a few inches off. A driveway curves around a tree that was not marked for removal. A retaining wall shifts to avoid a buried line.
An as-built survey checks the finished improvements in the field. It ties them to real measurements. It records:
- The location of the building or addition, measured to its actual corners
- Driveways and paved areas, as poured
- Retaining walls, as built
- Other site improvements listed in the survey scope
The surveyor ties these features to fixed points. This could be a property corner or a known elevation marker. That gives everyone a factual set of numbers. Not a guess based on the original drawing.
This is not a boundary survey. A boundary survey sets the property lines. An as-built survey shows where the built items sit. It shows this once construction is done, and relative to those lines.
Where the Project Landed Compared With the Approved Design
Construction rarely follows a design line for line. Crews make field changes. They avoid conflicts. They meet site conditions. They fix problems found mid-project. Some changes are small. Some are not.
An as-built survey gives a measured record of the finished condition. Architects, engineers, contractors, owners, and reviewing agencies can compare that record to the approved design. Each group decides what it means for their part of the project.
The survey does not rule on whether a project meets a code or permit. It just gives the numbers. A civil engineer might use those numbers to check a setback. A building inspector might use them to check a permit condition. The surveyor’s job is to measure and report. Not to approve or deny.
That difference matters. Do not treat an as-built survey as a stamp of approval. Treat it as a factual reference. The people who make that call still need to review it.
The Elevations and Finished Grades That Were Actually Built
Grading and elevation changes happen on most jobs. They are easy to miss once a site looks finished. An as-built survey can record:
- Finished floor and grade elevations
- Grade points called out in the design plan
- Elevations of features like retaining walls, curbs, or drainage structures
- Differences between proposed grades and what was actually built, when this is part of the scope
This is a different job than a topographic survey. A topographic survey maps the ground before design work starts. It gives engineers a starting point. An as-built survey records selected conditions after the work is done. That way, finished grades can be checked against the plan.
Not every as-built survey covers every elevation on a site. The scope depends on what the client, engineer, or reviewing agency needs on record. Talk to your surveyor before field work starts. Settle what gets measured.
The Site Record You Can Rely On for Future Project Decisions
A project closes out. The as-built survey does not lose its value. It becomes the record of what exists on the site. That record gets used again.
A future architect planning an addition needs to know where the current structure sits. An engineer fixing drainage needs current numbers. Not old numbers from a plan drawn years earlier. A contractor bidding a renovation needs to know where walls, pavement, and utilities actually are. Not where they were supposed to be.
An accurate as-built record supports decisions on:
- Building modifications
- Site improvements
- Renovations
- Expansion work
- Future engineering or surveying projects
Without this record, the next project team starts from scratch. They guess, use old drawings, or pay for a fresh survey that repeats work already done. A solid as-built survey saves that step.
What the Final Survey Can Reveal Before You Close Out the Project
The most practical use of an as-built survey comes early. It comes before the project record gets locked in. The survey can show gaps between the design and the finished work. It shows them while there is still time to review.
Maybe a wall sits closer to a setback line than planned. Maybe a grade does not match the drainage design. Catch these differences while the project team is still on the job. That gives everyone a chance to look at the numbers. They can decide if anything needs a second look.
Maryland projects do not all follow the same rule for when an as-built survey is required. Requirements can vary by county. They can vary by project type. They can vary by the reviewing agency involved. A small addition in one county may face different rules than a commercial site plan in another. Order an as-built survey based on the actual requirements. Ask the owner, engineer, architect, contractor, or agency reviewing the project. Do not assume every project needs the same scope of work.
If you are closing out a project, and are not sure if an as-built survey applies, ask the person handling your permit or design review. They will know what your county expects.
