As-Built Drawings of Existing Buildings
As-built drawings that record your building as it actually stands, ready to serve as a permit base, a legalization set or a permanent record.
- Stamped by a PE licensed in your state
- Built to IBC, IRC and local amendments
- Plan-check comments answered
Accurate drawings of what is already there
Many buildings have no usable drawings. Original plans get lost, homes are remodeled without records, and commercial spaces change tenants many times. Yet almost every permit for an existing building starts with a plan of existing conditions. As-built drawings fill that gap by documenting the building as it actually stands today, not as it was originally designed.
We prepare as-built drawings for houses, garages, accessory buildings, commercial suites and whole commercial buildings. Typical uses include a base for remodel and addition plans, legalizing work that was done without a permit, supporting a Certificate of Occupancy or change of use application, documenting square footage for a sale or appraisal, and creating facility records for owners and property managers.
As-built drawings are the starting point for most of our other architectural services. Once your building is documented, the same base drawing becomes the existing floor plan for a remodel, an addition or a tenant improvement, so you pay for the measurements only once. That also keeps every later drawing consistent with the building’s true dimensions.
What you receive
- Existing floor plans for each level
- Exterior elevations
- Site plan with structures and setbacks
- Roof plan and building section
- Room areas and square footage summary
- Fixture and equipment locations
What we document
The level of detail depends on what the drawings are for, and we scope it to that purpose.
Floor plans
Each level drawn to scale with walls, doors, windows, stairs, plumbing fixtures and major equipment, dimensioned from field measurements and labeled with room uses.
Exterior elevations
Every side of the building showing heights, roof lines, openings and materials, built from measurements and photos to support permits, appraisals and design work.
Site and plot plans
Structures located on the lot with distances to property lines, driveways, utilities and accessory buildings, based on recorded plats, surveys and field measurements.
Building sections
Cuts through the building showing floor-to-floor heights, ceiling heights, roof framing direction and crawlspace or basement conditions where they can be observed.
Area calculations
Gross and net floor area by level and by use, separating conditioned space, garage, porches and unfinished areas for zoning, appraisal and leasing purposes.
Existing systems layout
Locations of the electrical panel, water heater, furnace, condensers, meters and plumbing fixtures, which permit reviewers and MEP designers need as a starting point.
Your Stamped, Permit-Ready Plans Start With One Upload
Send your drawings or describe the project. A licensed engineer reviews it and sends a clear, fixed-fee proposal, often within hours.
- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
When you need as-built drawings
As-built drawings answer the question every reviewer and designer asks about an existing building: what is there now? Common reasons owners and contractors order them include:
- Remodel and addition permits, which require existing floor plans to compare against the new work.
- Legalizing unpermitted work, such as a garage converted without a permit or a basement finished years ago.
- Certificate of Occupancy and change of use applications for buildings with no plans on file.
- Tenant improvements in commercial spaces where the landlord has no current drawings.
- Real estate transactions, appraisals and refinancing that depend on accurate square footage.
- Insurance and disaster recovery, where drawings of the existing building support a claim or a rebuild.
- Facility management for owners who need accurate records for leasing, maintenance and future projects.
Contractors also use the term for record drawings at the end of construction, when field changes are marked up on the approved set. We can turn those redlines into a clean, updated record set for the owner.
Whatever the reason, the scope should match the purpose. A legalization set needs more detail than a square footage plan, and we confirm what your jurisdiction or lender requires before we start.
How as-built drawings are measured and drawn
Accurate as-built drawings begin in the field. Most of our projects are drawn from measurements and photos collected by the owner, the contractor or a local professional, following a measuring guide we provide. The guide covers what to measure in each room, how to record wall thickness, window and door sizes, sill and ceiling heights, and which photos to take. A laser distance measure makes the work faster and more accurate than a tape alone. Existing documents also help, including old permits, appraisal sketches, county assessor records and any previous survey, because they give us a cross-check on the overall footprint.
When the building is large, complex or the drawings support a legal or structural determination, a site visit may be needed. In those cases we can arrange one through a local licensed engineer.
Back in the office, we draft each level and cross-check the dimensions. Exterior dimensions must close, interior rooms must add up to the overall size, and stairs and walls must align between floors. Where numbers do not reconcile, we ask targeted questions or request a few more measurements rather than adjusting dimensions to fit. The result is a drawing you can rely on as a base for design and permits.
We also distinguish clearly between what was observed and what was assumed. Framing inside finished walls, the size of a beam hidden behind drywall or the depth of a footing cannot be seen, and the drawings say so rather than presenting a guess as fact.
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- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
As-built drawings to legalize unpermitted work
Unpermitted additions, garage conversions, finished basements and decks often come to light during a sale, an insurance claim or an application for a new permit. Most building departments offer a path to legalize the work, and it almost always starts with as-built drawings.
The process usually follows these steps:
- We document the unpermitted work as it exists, along with enough of the surrounding building to show how it connects.
- We review it against the code your jurisdiction applies and identify items that do not comply, such as missing egress windows, undersized beams, inadequate fire separation or missing alarms.
- We prepare plans showing the existing work plus the corrections needed, and submit them as a permit application.
- The inspector reviews the work in the field. Some jurisdictions require portions of walls or ceilings to be opened so framing, wiring and plumbing can be seen.
Where the building department asks for an engineer’s evaluation of existing framing or foundations, we provide it through our structural inspections and letters service. Being proactive generally gives you more control over cost and timing than waiting for the work to be discovered, and a well-prepared legalization set keeps the number of openings and corrections to a minimum.
Square footage and as-built drawings for records
Floor area matters for zoning, appraisals, leases and property taxes, and different parties measure it differently. We calculate areas according to the purpose. For homes, we can follow the approach of ANSI Z765, which separates finished above-grade area from below-grade and unfinished space. For commercial buildings, leasable area is often measured using the BOMA standards that many leases reference. For zoning and permit fees, we follow the definitions in your local code.
Each area calculation is shown on the drawings with a diagram, so anyone reviewing the number can see how it was derived. That transparency helps when an appraiser, a tenant or a zoning reviewer questions a figure, and it lets the number be updated easily after a future addition or remodel changes the building.
For owners of commercial properties, multifamily buildings and campuses, a complete as-built set becomes a long-term asset. Leasing agents use it to market space, facilities teams use it to plan maintenance, and design teams use it as the base for the next renovation. When a project then needs permit drawings, the existing plan is ready, and new work such as a tenant improvement can begin from an accurate base immediately.
We deliver as-built sets as PDF drawings formatted on standard sheets, ready to submit or archive.
You likely need as-built drawings if
- Your city asked for existing floor plans
- You are legalizing unpermitted work
- You have no plans for your building
- You need accurate square footage
- You are applying for a Certificate of Occupancy
- You are planning a remodel or addition
How it works, start to finish
From your first message to stamped drawings, you work directly with the engineering team.
- 1Share your projectSend the address, scope and any drawings, photos or plan-check comments. Two minutes is enough.
- 2Receive a fixed-fee proposalAn engineer reviews the scope and replies with a firm price and delivery date for your as-built drawings drawings.
- 3Engineering and draftingWe run the calculations and prepare drawings to the codes your jurisdiction enforces, checked before sealing.
- 4Stamped set deliveredYou receive a sealed PDF set ready to submit, and we answer any plan-check comments within scope.
Standards we follow for as-built drawings
As-built drawings are prepared to support review under the codes and measurement standards that apply to your project:
- International Existing Building Code (IEBC) for existing buildings
- International Residential Code (IRC) and International Building Code (IBC)
- ANSI Z765 for residential square footage
- BOMA floor measurement standards for commercial space
- Your local permit submittal requirements
How licensing works. Engineering drawings must be sealed by a Professional Engineer licensed in the state where your project is located. PE Engineer works with a network of state-licensed PEs, so every set is reviewed and stamped by an engineer with an active license in the state where your project is located. Their name and license number appear on the seal, exactly as your building department requires.
Related services
Floor PlansDimensioned existing and proposed floor plans with walls, doors, windows, fixtures, egress and room data, drawn to the detail plan reviewers expect.Explore More
Remodel & Renovation PlansKitchen, bath, basement, attic and whole-house remodel plans showing existing conditions, demolition and new work, with structural changes engineered.Explore More
Structural Inspections & LettersSealed structural inspection reports and engineer letters for foundations, cracks, framing, damage, unpermitted work and existing buildings, written for the people who requested them.Explore MoreFrequently asked questions
What are as-built drawings?
As-built drawings are measured drawings that show a building as it actually exists, including later changes not on the original plans. They typically include floor plans, elevations, a site plan and area calculations, and are used as the base for permits, legalization and property records.
Do you visit the property to measure it?
Most as-built drawings are prepared from measurements and photos collected by the owner, contractor or a local professional using our measuring guide. When a site visit is required because of the building’s size, complexity or purpose, we can arrange one through a local licensed engineer.
Can as-built drawings help legalize work done without a permit?
Yes. They are usually the first document a building department asks for. We document the existing work, identify what does not meet code, and prepare plans showing the needed corrections so you can apply for a permit to legalize it.
How accurate are as-built drawings?
They are as accurate as the measurements behind them, which is why we cross-check every dimension and ask for more information where numbers do not reconcile. Concealed conditions such as framing inside walls are noted as assumed unless they can be observed or opened.
What is the difference between as-built and record drawings?
The terms are often used interchangeably. Record drawings usually mean the approved construction set updated with field changes at the end of a project. As-built drawings can also mean drawings created from scratch for an existing building with no plans. We prepare both.
How long do as-built drawings take?
For a typical house, as-built drawings are delivered within a few business days of receiving complete measurements and photos. Larger homes and commercial buildings take longer depending on size and the number of levels. We confirm the schedule with your fixed-fee quote.
Get your free as-built drawings proposal
Tell us where the project is and what you need. Attach any drawings, photos or plan-check comments. A licensed engineer reviews every request.
- Upload your filesPlans, sketches, photos or comments
- Get a fixed-fee proposalUsually the same day
- Receive stamped drawingsSealed by a PE licensed in your state