For most of construction history, as-built drawings meant one of three things: hire a surveyor, rent a laser scanner, or send someone to the site with a tape measure and enough patience to fill a legal pad.

That assumption made sense when it was true. It's worth revisiting now.

Space Mode in Polycam captures spatial geometry in real time as you walk a space. The output is a dimensioned, layered, CAD-ready floor plan, and it is available before you leave the building. The question isn't whether a phone can produce as-built documentation anymore. It's whether the output meets the standard the job requires.

For most of the work that drives as-built demand, it does. Here's what the workflow looks like and where the honest limits are.

Why Manual As-Built Documentation Falls Short

The tape measure workflow has a compounding error problem.

Field measurements go into notes. Notes become sketches. Sketches go to a drafter, sometimes the same person, often not. The drafter produces a CAD file from a hand sketch made under time pressure in a space that may or may not have had good lighting. Details that seemed obvious on-site get ambiguous on paper. Ceiling heights, rough opening widths, wall thicknesses, and fixture offsets can be wrong by the time they reach the drawing.

The downstream costs aren't abstract. For GCs, inaccurate as-builts show up as design coordination problems, permit revision cycles, and change orders. For architects, they show up as drawings that don't match field conditions when construction starts, which means someone goes back to the site, which means the project slows down.

The process works until it doesn't. And when it doesn't, the fix is another site visit.

How To Create As-Builts With Your Phone

Here's the practical sequence, in plain terms.

Equipment

Any iPhone or iPad running Polycam. No additional hardware, no rental equipment, no operator certification. If you're carrying your phone, you're already carrying the scanner.

Capture

Open Polycam, select Space Mode, and walk the space slowly, moving the phone up and down as you go and working your way around the room in one consistent direction. The app automatically detects and maps walls, windows, doors, fixtures, and furniture as you move, so you don't mark anything manually. A good rule of thumb is 2 minutes per 100 square feet. Rushed scans miss detail and reduce dimensional accuracy.

On-site review

When the capture is complete, dimensions surface immediately on your screen. Verify room dimensions, ceiling heights, rough opening sizes, and wall runs while you're still in the building. If something looks off, like a wall dimension that doesn't match what you're looking at or a fixture that didn't register, you correct it before you leave. This is the accuracy checkpoint. Not the desk. Not the drafter's inbox. Here, while the space is still in front of you.

Export

Choose the format the job requires. DXF for AutoCAD or Revit. PDF or PNG for permit submissions or client handoffs. SVG for design tools. On-device processing works without an internet connection and takes a few minutes for most spaces. For larger jobs over 5,000 sq ft, cloud processing is recommended as it handles the additional data significantly faster. The file is ready when you walk out the door.

JNR Architecture captured an entire house in one hour using this workflow, compared to an estimated 16 hours of manual measurement for the same space. Esteban Martinez Homes reduced site documentation time by 90% and cut preliminary site visits by two-thirds.

What the Output Actually Looks Like and What It Can Be Used For

Professionals evaluating this for real work need specifics, not a demo reel. Here's what you actually get.

The DXF export is a layered file with walls, openings, fixtures, and room labels on separate named layers. It imports directly into AutoCAD and Revit as a drafting baseline. Layer structure stays intact through the import. Nothing collapses or needs to be rebuilt. Your drafter gets geometry they can work with, not a flat image to trace over.

The same capture simultaneously produces a 3D spatial model with embedded measurements. That model lives in your Polycam library and can be revisited after the site visit: pulling a ceiling height you forgot to note, checking a wall run, confirming a rough opening, all without scheduling a return trip.

Polycam also generates a spatial report from the scan and downloads it as a PDF. It includes room-by-room square footage, wall surface area, and a fixture inventory. Drop it into Excel for a material takeoff or into Procore for project documentation.

Total export formats: 15+, including DXF, PDF, PNG, SVG, OBJ, FBX, and point cloud formats compatible with AutoCAD, Revit, SketchUp, Blender, and Rhino.

What this output is not: a certified survey or a stamped engineering document. What it is: a verified, dimensioned, CAD-ready record of field conditions that eliminates manual measurement and desk redrawing for the range of work that makes up the majority of as-built demand.

Where Phone-Based As-Builts Fit and Where They Don't

Polycam's Space Mode is not a certified survey instrument. For projects that require stamped as-built drawings for structural engineering, jurisdictions with strict survey tolerances, or legal documentation purposes, a licensed surveyor or registered professional is still the right call. That work exists and it has specific requirements that a phone scan doesn't fulfill.

For the range of work that makes up most GC and design-build volume, such as renovation scoping, pre-design existing conditions documentation, permit close-out on residential and light commercial jobs, subcontractor bid packages, and facilities records, the output from a phone scan meets the practical standard of the work. The on-site dimension review is the quality control mechanism. You verify accuracy at the source, in the field, before the file leaves your hands.

The professional's judgment determines when the output is sufficient for the job. This article isn't making that call for you. It's giving you an accurate picture of what the tool produces so you can make it yourself.

Getting the As-Built Into the Right Hands

Producing the as-built is half the job. Getting it to the people who need it is the other half.

Polycam's shareable link lets anyone, an architect, structural engineer, owner, or remote project manager, review the full 3D spatial model without installing software or requesting a file transfer. They can pull measurements, check conditions, and understand scope from wherever they are. No additional site visit. No back-and-forth to confirm a dimension.

On the Business plan, captures are stored in a shared team library with folder-level access controls, spatial comment threads, and saved measurements. The field tech who scanned on Monday doesn't have to be the point of contact every time someone needs to reference the space. The record lives in the project, accessible to the team, for the life of the job.

That's a different model than as-built documentation has traditionally operated on, where the file lives in someone's email attachments and a return site visit is the default answer to any follow-up question.

Conclusion

As-built documentation has always been a necessary cost of doing construction correctly. The question is how much time and money that cost consumes per job.

A phone-based workflow that produces a verified, layered, CAD-ready as-built before you leave the site changes that math, and it does it with hardware most professionals are already carrying. The Business plan is what unlocks the full workflow: floor plan generation, layered DXF export, AI spatial reports, team sharing, and shareable links for remote review.

Try it free for 7 days at poly.cam/pricing. No equipment to rent, no scanner to learn, no return trip because the dimensions were off.

Three FAQs, all pulled directly from the article — nothing invented:

Can I create as-built drawings with my iPhone? Yes. Polycam's Space Mode runs on any iPhone or iPad with no additional hardware, no rental equipment, and no operator certification. As you walk a space, the app automatically detects and maps walls, windows, doors, fixtures, and furniture in real time. The output is a dimensioned, layered, CAD-ready floor plan that exports as a DXF for AutoCAD or Revit, a PDF or PNG for permit submissions, or one of 15+ other formats — and it is available before you leave the building.

How accurate is a phone-based as-built compared to manual measurement? Accurate enough to use as a drafting baseline for the range of work that drives most as-built demand. Dimensions surface immediately on-screen when the capture is complete, so room dimensions, ceiling heights, rough opening sizes, and wall runs are verified on-site rather than at the desk. JNR Architecture captured an entire house in one hour with this workflow, compared to an estimated 16 hours of manual measurement for the same space. Esteban Martinez Homes reduced site documentation time by 90% and cut preliminary site visits by two-thirds. The on-site review is the quality control mechanism — accuracy is verified at the source, in the field, before the file leaves your hands.

When should I use a licensed surveyor instead of a phone scan? Polycam's Space Mode is not a certified survey instrument. For projects that require stamped as-built drawings for structural engineering, jurisdictions with strict survey tolerances, or legal documentation purposes, a licensed surveyor or registered professional is the right call. Phone-based as-builts fit the practical standard for renovation scoping, pre-design existing conditions documentation, permit close-out on residential and light commercial jobs, subcontractor bid packages, and facilities records. The professional's judgment determines when the output is sufficient for the job.