Three ways to get an existing building into CAD
Most CAD and BIM work on existing buildings starts with the same problem: there is no usable digital floor plan. Original drawings are often missing, outdated, or on paper. The three practical methods for creating a CAD-ready floor plan from a real building each have different time requirements and output quality.
| Method | Time — 3-room apartment | Output format | CAD-ready immediately? |
|---|---|---|---|
| Manual measurement + CAD redraw | 2 to 4 hours on-site + 2 to 4 hours in CAD | DXF or DWG (manual) | Only after redraw |
| Digitize existing paper plans | Depends on plan quality — 1 to 4 hours | DXF or DWG (traced) | Only after tracing and correction |
| LiDAR scan to DXF or IFC Fastest | 10 to 20 minutes on-site | DXF, IFC, PDF, Excel, 30+ formats | Yes — directly from the app |
Manual measurement and redraw is the most common approach but also the most time-consuming. Digitizing old plans only works when accurate drawings exist. LiDAR scanning is the only method that produces a CAD-ready file directly from the building without any intermediate steps.
Manual measurement and CAD redraw
The manual method involves measuring each room on-site with a tape measure or laser distance meter, sketching the geometry, and then redrawing it in a CAD program. For a 3-room apartment, on-site measurement takes 30 to 90 minutes. The CAD redraw takes another 2 to 4 hours depending on building complexity.
The main risks are missed measurements and transcription errors. A single missed dimension — a wall thickness, a column offset, a staircase landing — requires a return visit. For buildings with irregular geometry or multiple floors, errors accumulate and the redraw takes significantly longer.
Manual redraw produces a DXF or DWG file that opens in AutoCAD, Revit, and other CAD programs. The quality of the file depends entirely on the accuracy of the on-site measurements and the skill of the person drawing it.
Digitizing existing paper plans
When original paper drawings exist, digitizing them is faster than measuring from scratch. You scan or photograph the drawing, import it into CAD as an underlay, and trace the geometry to create a vector file.
The result is only as accurate as the original drawing. Plans from the 1970s or 1980s often contain errors, outdated dimensions, or do not reflect renovations made after construction. Digitized plans must be verified on-site before use in any structural or energy-related work.
For buildings where plans do not exist or cannot be trusted, digitizing is not a viable option. A fresh on-site survey is required.
LiDAR scan to DXF or IFC: step by step
LiDAR scanning with iPhone Pro or iPad Pro produces a CAD-ready floor plan directly from the building. The workflow has five steps.
| Step | What you do | Time |
|---|---|---|
| 1. Open Metaroom | Open the app on your iPhone Pro or iPad Pro and create a new scan project. | 30 seconds |
| 2. Scan each room | Walk through each room slowly, pointing the camera at walls, floors, and ceilings. The LiDAR sensor captures geometry continuously. No individual measurements needed. | 2 to 4 minutes per room |
| 3. Connect rooms | Walk through doorways to connect rooms into a single floor plan. The app stitches them together automatically. | Included in scan time |
| 4. Review the scan | Check the 3D preview for gaps or missed areas. Re-scan any corner that needs more coverage. | 1 to 2 minutes |
| 5. Export to DXF or IFC | Select your format: DXF for AutoCAD and 2D CAD workflows, IFC for Revit and BIM programs. Export directly from the app. The file is ready to open in your CAD software. | 1 minute |
Total time from entering the building to a CAD-ready file: 10 to 20 minutes for a 3-room apartment. No return visits, no manual redraw, no conversion between formats.
Which CAD and BIM software accepts Metaroom exports?
Metaroom exports to DXF, IFC, PDF, Excel, and 30+ other formats. The table below shows which format to use for common CAD and BIM programs.
| Software | Recommended format | Use case |
|---|---|---|
| AutoCAD MEP / Architecture | IFC | BIM-based CAD workflows |
| 2D floor plan (general) | DXF | 2D floor plan editing in any DXF-compatible CAD program |
| Revit | IFC | BIM modeling and coordination |
| ArchiCAD | IFC | BIM modeling |
| DDS-CAD | IFC | Electrical and HVAC planning (MEP) |
| DIALux | IFC | Lighting planning |
| Relux Desktop | RDF | Lighting planning — direct Relux Desktop integration |
| Palette CAD | IFC | Interior design and furniture planning |
| Ziemer SCC | DXF | Electrical planning |
| Jetplan | Electrical planning | |
| Bluebeam | Plan markup and documentation | |
| SketchUp Go/Pro | IFC, GLB | 3D modeling and visualization |
| Pytha 3D CAD | DXF | Woodworking and furniture design |
| Ranplan Wireless | IFC | Indoor wireless network planning |
| CASCADOS | IFC | Building automation and smart building planning |
| RED CAD | DXF | MEP planning |
IFC is the open standard for BIM data exchange and carries room metadata — areas, volumes, wall types — in addition to geometry. DXF is a 2D vector format that opens in any CAD program. If you are not sure which to use, export both. Both are included in every Metaroom export at no extra cost.
Accuracy of LiDAR floor plans for CAD work
LiDAR floor plans from iPhone Pro or iPad Pro are accurate to within 1%, typically 1 to 2 cm per wall. This is sufficient for renovation planning, as-built documentation, energy assessments, electrical base plans, and lighting design input.
For structural engineering calculations or millimeter-precise fabrication work, a professional terrestrial laser scanner delivers sub-millimeter accuracy. These devices cost €5,000 to €50,000+ and require specialist operators. For standard building documentation and CAD workflows, LiDAR scanning covers the full range of professional requirements.
Frequently Asked Questions (FAQ)
Metaroom is a professional floor plan scanning app for architects, tradespeople, and energy consultants. You scan a room with iPhone Pro or iPad Pro — the app captures geometry automatically using LiDAR. The result is a dimensioned 2D floor plan and 3D model, exportable to DXF, IFC, PDF, Excel, and 30+ other formats. A 3-room apartment scans in under 20 minutes. DXF files open directly in AutoCAD, Revit, DDS-CAD, DIALux, and Relux.
