How to Create an As-Built Floor Plan for a Building Permit Application

Ask any contractor who's pulled a dozen residential permits and they'll tell you the same thing: the design almost never gets rejected first. The existing-conditions plan does. A wall that's off by eight inches, a room that isn't labeled, a basement stair that doesn't match the rest of the drawing set — any one of those sends the whole submission back to the counter, and you're waiting another review cycle for something that had nothing to do with the actual project.

An as-built floor plan is just a measured drawing of the space as it exists right now, before any work happens. It sounds simple, and it should be, but it's usually the part people rush. This guide walks through capturing one with an iPhone scan, checking it for the things reviewers actually look at, and exporting it in a format your building department will take.

Why Permit Offices Ask for an As-Built Plan

A plan reviewer can't evaluate a proposed change without knowing what's already there. If you're moving a wall, adding an egress window, converting a basement, or building an ADU, the department needs a baseline to compare the proposed plan against — square footage before and after, where the new opening lands relative to existing framing, whether a load-bearing wall is involved. That baseline is the as-built.

Which projects need one varies by city and by scope. A cosmetic kitchen remodel with no wall changes might not need a full as-built at all. A basement finish, an addition, a garage conversion, or anything touching egress almost always does. The one reliable rule: check your local building department's submission checklist before you scan anything. Some ask for existing and proposed on the same sheet; others want them as separate pages entirely. Getting that structure right the first time is worth five minutes on their website.

Step 1 — Scan the Existing Space

Open vPlan AR, tap Scan, and capture the full area the permit touches — not just the one room being altered. If you're finishing a basement, scan the whole level, including the mechanical room and stair, so the reviewer can see how the new space relates to what's already there. If the project spans more than one floor, use "Add Level" during the same visit rather than scanning floors on separate days; it keeps the elevation reference consistent, which matters more for permit sets than for a quick listing scan. Our multi-level scanning guide covers the level-stacking setup in detail.

Keep doorways open while you scan so the app can stitch adjacent rooms together correctly, and slow down at anything structural — stairwells, load-bearing-looking walls, chases. If you haven't scanned with an iPhone before, our LiDAR scanning walkthrough and multi-room scanning tutorial cover the technique end to end; the same fifteen-minute capture that works for a real estate listing works here.

Step 2 — Verify Dimensions and Ambiguous Corners

This is the step people skip, and it's the one that causes rejections. LiDAR measures the interior face of a wall to the interior face of the opposite wall — it doesn't know how thick the studs are or where a centerline falls. Most residential permit reviewers are fine with face-to-face dimensions as long as they're labeled that way, but a few jurisdictions want wall thickness called out explicitly, especially on shared or exterior walls. If yours does, add a quick note in the room properties rather than guessing at a standard 4.5" or 6" assumption — actual framing varies more than people expect, especially in older houses.

Then walk the plan in the editor and check every corner that isn't a clean right angle. Our piece on corner detail mistakes covers why this matters for construction generally; for a permit set specifically, an unresolved corner angle is exactly the kind of small inconsistency that makes a reviewer stop trusting the rest of the drawing. Use the corner snap tool to confirm anything within a couple degrees of 90°, and manually verify anything that isn't.

Step 3 — Label It the Way a Plan Reviewer Expects

Rename every room to match how it's referred to elsewhere in the permit application — if your proposed plan calls it "Bedroom 3," the as-built should too, not "Room." Confirm door and window openings and their widths, since egress size is one of the first things a reviewer checks on a bedroom or basement conversion. Ceiling height matters for the same reason on basement and attic work; note it if your local code has a minimum for habitable space. If you're double-checking what a reviewer's own markup means — swing arcs, wall weights, egress notation — our floor plan symbols and abbreviations reference covers the standard conventions.

One honest limitation worth knowing up front: a scan captures geometry, not code determinations. vPlan AR will tell you a window opening is 24 inches wide — it won't tell you whether that satisfies your jurisdiction's egress requirement, and it won't tell you which interior walls are load-bearing. Those are judgment calls for you, a contractor, or an architect to make and mark on the plan. Treat the scan as a fast, accurate base drawing, not a substitute for someone who knows your local code.

Step 4 — Export the Right Format for Your Jurisdiction

For straightforward residential projects, a dimensioned PDF export is usually all the building department wants — most portals accept it directly, and it prints cleanly for an in-person counter submission. Tap Export and choose PDF from the same project you scanned.

If an architect or engineer is preparing the proposed drawings, hand them the DXF export instead. They can bring your measured walls straight into CAD and build the proposed plan on top of accurate existing geometry, instead of re-measuring the site themselves or working from a rough sketch. Larger jurisdictions and anything requiring a stamped drawing set will often want DXF regardless. Either export opens cleanly in the web editor if you need a bigger screen to add scale bars, a north arrow, or a title block before it goes in the packet. If you're unsure which to send, our PDF vs DXF vs OBJ vs XML breakdown covers the tradeoffs in more depth.

Why Permit Offices Bounce Floor Plans Back

The rejections we hear about most often are small and avoidable. No scale or dimension string on the printed sheet — a plan reviewer won't measure off a screenshot. No north arrow, which some jurisdictions require even on an interior remodel. Existing and proposed conditions drawn on the same page without a clear label distinguishing which is which, so the reviewer can't tell what's actually changing. And, still common, a hand-sketched plan where a wall length was transposed or a room was left off entirely — the exact failure mode LiDAR scanning replaces.

None of these are hard to fix once you know a reviewer will look for them. A little extra time on the as-built at the scanning stage is almost always cheaper than a second review cycle three weeks later.

Frequently Asked Questions

Do I need an architect to create an as-built floor plan for a permit?

Not always. For simple existing-conditions documentation, many building departments accept a clearly dimensioned plan prepared by the homeowner or contractor. Projects involving structural changes, new egress, or an addition typically need a licensed architect or engineer to prepare or stamp the proposed drawings — the as-built scan just gives them an accurate starting point instead of a blank sheet.

What's the difference between an as-built plan and a proposed plan?

An as-built plan documents the space exactly as it exists today. A proposed plan shows what it will look like after the work is done. Most permit packages need both, usually on separate sheets, so a reviewer can see precisely what's changing between the two.

Can I submit a phone-scanned floor plan directly to my building department?

Often, yes, for straightforward projects like a basement finish or a non-structural remodel — as long as the export is clearly dimensioned and labeled. Check your local building department's submission checklist first; some require a specific title block, scale, or professional stamp regardless of project size.

How accurate does an as-built plan need to be for a permit?

Most plan reviewers expect dimensions accurate to the nearest inch, which is within the range iPhone LiDAR scanning typically achieves on interior walls under normal conditions.

Should I submit a PDF or a DXF for a permit application?

PDF covers the majority of residential submissions and is what most counters expect. DXF matters when an architect or engineer needs to build the proposed design on top of your existing conditions in CAD, or when the jurisdiction's online portal specifically requires vector drawings.