How to create an as-built floor plan, from site walk to CAD

Two ways to make one: measure and redraw, or scan and export

Every as-built floor plan ends as a scaled drawing of what is really there. The difference is how many times the numbers pass through your hands on the way.

Manual times: amrax, a scanning vendor.^[1] Scan time: Ersoz and Bosché, ISARC 2026.^[2]

Step	Tape and redraw	Scan and export
On site	Measure each room, sketch it, photograph the walls	Walk once with an iPhone or iPad Pro; the plan draws itself
Back at the desk	Type every dimension into CAD and close the loops	Open the DXF as the base drawing
Missing dimension	Drive back	Measure it on the plan or replay the walk
Time	30-90 minutes on site plus 2-4 hours of redraw for a three-room apartment, by one vendor's estimate	32 minutes from scan to model for a house and two office floors in a 2026 study of a RoomPlan app

The rest of this guide is the scan route, step by step, from the site walk to a drawing you can design on.

Step 1: Get the building ready

• Light. Turn on the lights and open the blinds. Apple recommends at least 50 lux for RoomPlan.^[3]
• Doors. Open every interior door so the scan can follow you from room to room.
• Mirrors and glass. Apple names full-height mirrors and glass walls as hard cases for LiDAR.^[3] A wall PlaceAnew could not see is drawn dashed.
• One floor at a time. Each floor of a house is its own scan.

Step 2: Walk the building once

Start PlaceAnew, start a new scan and walk calmly, sweeping the camera from floor to ceiling along each wall. PlaceAnew outlines walls, doors, windows, openings and furniture as it finds them and records a video of the walk at the same time.

Keep each room's scan short and the house within Apple's limits: rooms up to 30 by 30 feet and scans under 5 minutes,^[3] and about 2,000 square feet for a whole single-floor home.^[4]

Step 3: Look over the plan before you leave the site

This is the step that saves the second trip. Open the floor plan while you are still standing in the house.

• Dashed walls are walls PlaceAnew could not see and filled in from what it did see. Look at each one.
• "Estimate" labels mark anything PlaceAnew estimated, so a filled-in number never looks like a measured one.
• Fix a wall or a door in seconds in the editor: move a wall, add or change a door or window, rename a room. Earlier versions are kept.
• Measure anything with the measure tool on the plan.

Step 4: Design on the scanned dimensions

A scan gives you a reliable layout. In the 2026 ISARC study, a RoomPlan app found all 8 rooms of a house and came within about 5% of the laser-scanned total room area.^[2] In our own office, all 7 wall lengths that compare one to one with a hand-measured plan came within 2.5 inches, median under 1 inch, and the longest wall, 17' 2", came out a third of an inch long.^[5]

• Dashed walls and estimates show what PlaceAnew filled in, so your drawing knows which lines were measured.
• Walk replays the visit. A sill, a radiator or a beam is a tap away at your desk, not a drive.
• Interior walls come in as lines, the way a layout plan shows them.^[5] Give them your wall types when you draw.

Step 5: Export to CAD and draw

1. Export the DXF from the share button and send it by AirDrop or Mail, or save it to Files. The same scan also gives PDF report, SVG drawing, DXF for CAD and USDZ 3D model.
2. Open the DXF in your CAD program as the existing-conditions base.
3. The DXF is drawn in meters.^[6] If your template works in feet and inches, insert it with that unit so the plan lands at full size.
4. Draw your walls on your own layers and standards over it, and keep the scan layer for reference.

Step 6: Title it honestly

Call it "Existing conditions" and note the method: "Measured by LiDAR scan with PlaceAnew on [date]." A professional liability insurer advises design professionals to avoid drawings titled "As-Built", because the word suggests an exact, certified depiction.^[7] See what as-built drawings are for the difference.

What belongs on an as-built floor plan

• Every wall, with overall and room dimensions
• Room names and areas, and the total
• Doors with their swings, windows and open passages
• Stairs, fixtures, built-ins and the furniture that stays
• Ceiling heights where they change
• Scale, north arrow, date and how it was measured

PlaceAnew gives you the walls, rooms, areas, doors, windows and furniture from the walk. You add the north arrow and your title block.

Questions about as-built floor plans

Working from an iPhone? Read what an iPhone as-built captures. Architects: PlaceAnew for architects.