What as-built documentation is
As-built documentation records the actual physical state of a building at a specific point in time. It differs from original construction drawings, which show the design intent — not what was actually built or what the building looks like after decades of modifications.
As-built surveys are required before renovation, before energy retrofitting, before BIM modeling of existing structures, and for regulatory submissions in many jurisdictions. The document needs to reflect current reality — actual wall positions, real room dimensions, existing window and door locations — not an architect's original plan from 30 years ago.
Why original drawings are not enough
Most buildings accumulate changes over their lifetime. Walls are moved, rooms are divided, extensions are added, and services are rerouted. Original drawings rarely reflect these changes. Three specific problems make original drawings unreliable for as-built work.
Drawings are missing entirely
Buildings constructed before the 1980s often have no surviving drawings. Local authority archives are incomplete, and private owners rarely retain original plans across ownership changes.
Drawings do not reflect current state
Even when drawings exist, they typically show the original design. Renovations, extensions, and changes made without permits are not recorded. The drawing and the building diverge over time.
Drawings are not in a usable digital format
Paper drawings or scanned PDFs cannot be used directly in CAD or BIM software. They must be redrawn — which takes hours and introduces errors — before any design work can begin.
A fresh as-built survey solves all three problems. It captures what exists today, in a digital format that opens directly in CAD and BIM software.
As-built survey methods compared
| Method | Time — 3-room apartment | Output | CAD-ready immediately? |
|---|---|---|---|
| Tape measure + manual CAD redraw | 4 to 8 hours total | DXF or DWG (manual) | Only after redraw |
| Laser distance meter + manual CAD redraw | 2 to 4 hours total | DXF or DWG (manual) | Only after redraw |
| LiDAR scan (iPhone Pro) Fastest | 10 to 20 minutes on-site | Automatic 2D floor plan + 3D model | Yes — via Metaroom Workspace |
| Terrestrial laser scanner | 1 to 3 hours on-site + processing | Point cloud, requires post-processing | Only after specialist processing |
LiDAR scanning is the only method that produces a CAD-ready as-built floor plan without a manual redraw step. The 2D floor plan and 3D model are generated automatically from the scan and available for export via the Metaroom Workspace — accessible in a browser or from the Export button in the app.
LiDAR scanning workflow for as-built documentation
The following workflow produces a complete as-built floor plan, 3D model, and photo documentation in a single on-site visit.
| Step | What you do | Time |
|---|---|---|
| 1. Scan each room | Walk through each room with iPhone Pro or iPad Pro. The LiDAR sensor captures wall positions, ceiling height, and floor geometry continuously. No individual measurements needed. | 2 to 4 minutes per room |
| 2. Connect rooms | Walk through doorways to stitch rooms into a complete floor plan. The app connects room geometry automatically. | Included in scan time |
| 3. Capture Snapshots | Photograph existing conditions — wall construction, window types, services locations, visible damage or defects — using Metaroom's Snapshot feature. Photos are linked to their position in the floor plan. | 5 to 15 minutes |
| 4. Add Notes | Attach text notes to specific locations in the floor plan — material types, structural observations, access constraints — directly in the app. | 2 to 5 minutes |
| 5. Export | Open Metaroom Workspace — via browser at studio.amrax.ai or from the Export button in the app — and export as DXF, IFC, PDF, or the project report with floor plan, room data, and photos. | 1 to 2 minutes |
Total on-site time for a 3-room apartment: 20 to 40 minutes including photos and notes. The resulting documents are ready for immediate use in CAD, BIM, or regulatory submissions.
What a LiDAR as-built survey produces
A Metaroom as-built survey produces four usable outputs from a single on-site visit.
| Output | Format | Used for |
|---|---|---|
| Dimensioned 2D floor plan | PDF, DXF | Renovation planning, permit applications, client handover |
| 3D building model | IFC, GLB, OBJ, and more | BIM modeling, design visualization, clash detection |
| Room data table | Excel (XLS) | Area calculations, energy assessments, quantity takeoffs |
| Project report | Complete as-built record with floor plan, room data, and photos — ready to submit or share |
Accuracy for as-built work
LiDAR scanning with iPhone Pro or iPad Pro delivers accuracy within 1%, typically 1 to 2 cm per wall. This is sufficient for renovation planning, energy retrofitting, BIM input, and most regulatory documentation.
For structural engineering calculations requiring sub-millimeter precision, a terrestrial laser scanner or total station is more appropriate. These instruments cost €5,000 to €50,000+ and require specialist operators. For standard as-built documentation across architecture, construction, and energy consulting, LiDAR scanning covers the full range of professional requirements.
If walls are being opened up or structural elements exposed during renovation, scan the space before works begin to capture existing conditions, and scan again after to document what was found and what was changed. Both scans take under 20 minutes and produce a permanent record of the building at each stage — useful for insurance, warranty, and future maintenance.
Frequently Asked Questions (FAQ)
Metaroom is a professional floor plan scanning app for architects, tradespeople, and energy consultants. You scan a building with iPhone Pro or iPad Pro — the app captures existing conditions automatically using LiDAR. The result is a dimensioned 2D floor plan, 3D model, room data table, and project report with photos. Accuracy is within 1%. Exports include DXF, IFC, PDF, Excel, and 30+ other formats. A 3-room apartment scans in under 20 minutes.
