As-Built Drawings: When You Need Them for a Permit or Certificate of Occupancy
As-built drawings show a building exactly as it was actually built, not as it was designed. Building departments ask for an as-built plan when construction changed from the approved permit drawings, when work was done without a permit, or before issuing a certificate of occupancy for an existing structure. A typical as-built set includes measured floor plans, elevations and a site plan, plus structural and MEP information where the city needs to verify it.
What are as-built drawings?
As-built drawings (sometimes called record drawings or existing-conditions plans) document the real, finished state of a building. They are drawn from field measurements and photos rather than from the original design, so they capture every wall that moved, window that changed size, or room that was added along the way.
When a city asks for an as-built plan
The most common situations are:
- Certificate of occupancy or occupancy permit for a building whose drawings are missing or out of date; see certificate of occupancy vs building permit
- Legalizing unpermitted work, such as a garage conversion, basement finish or addition built without a permit
- Changes made during construction that differ from the approved permit set
- Change of use or occupancy, for example turning a house into an office
- Refinancing, sale or insurance, where a lender or buyer needs accurate square footage
What an as-built set includes
At minimum, expect a site plan with property lines and setbacks, measured floor plans with room names and dimensions, and exterior elevations. If the city needs to verify the structure or systems, the set also includes framing and foundation information and electrical, plumbing and mechanical layouts. Anything that can't be seen, such as hidden framing, may need to be opened up or noted as an assumption.
As-built drawings for unpermitted work
When work was done without a permit, the as-built set is the starting point for a permit after the fact. The city reviews it like a new permit application and may ask you to open walls for inspection. Read what happens if you build without a permit and how to legalize unpermitted work for the full process.
Turning old plans into as-built drawings
If you have the original plans as a PDF, a scan or a paper blueprint, they can be converted to CAD and then updated to match the measured conditions, which is faster than drawing from scratch. See our PDF to CAD and Revit conversion service and our architectural drawings service.
Frequently asked questions
What is an as-built drawing?
An as-built drawing shows a building exactly as it was constructed, based on field measurements, including any changes from the original design.
Do I need as-built plans for an occupancy permit?
Often, yes, if the building's approved drawings are missing, out of date, or don't match what was built. The city uses the as-built plans to review the building before issuing a certificate of occupancy.
What is the difference between as-built and permit drawings?
Permit drawings show proposed work for approval before construction. As-built drawings show what was actually built after construction.
Can my old PDF plans be used for as-builts?
Yes. Old PDF or paper plans can be redrawn in CAD and updated with field measurements to create an accurate as-built set.
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