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A facade survey is the precise, complete measurement of a building’s external walls and openings. Its purpose is to provide reliable geometry data for planning, renovation, tendering and documentation, ideally captured digitally and ready for further processing. As a digital facade survey, it creates the basis for an accurate measurement of the facade.
Why is a facade survey important?
- Reliable basis: Exact dimensions for insulation, cladding, windows/doors, fixings and details.
- Efficiency and cost control: Reduces change orders, repeat site visits and material waste.
- Evidence and funding: Clean quantities and tolerances support quotations, approvals and funding applications.
- Digital workflows: Data flows directly into CAD/BIM, tender documents and installation planning.
How a facade survey works in practice
- Data capture:
- Photogrammetry/drone surveys for large-scale views, orthophotos and hard-to-access areas.
- Mobile LiDAR (SLAM) for supplementary interior and connection measurements.
- Evaluation: Derivation of orthographic projections, facade elevations, dimensions, opening schedules (windows/doors) and grid axes; optionally scan-to-BIM for building elements/attributes as well as facade recording and 3D laser scan evaluation.
- Handover: Open formats: E57/LAS/LAZ (point clouds), orthorectified images (GeoTIFF/JPG with world file), 2D plans (DWG/DXF/PDF), BIM (IFC), including metadata on version, units, coordinates and accuracy.
- Use: Quantity take-off, detailed planning (connections, substructure), clash detection, renovation and documentation (as-built).
Common errors and misunderstandings
- Missing references: Without control points/targets, reliable georeferencing and tolerances are missing.
- Gaps/shadowed areas: Uncaptured recesses or canopies lead to incorrect quantities. A coverage check is essential.
- Image instead of measurement: Photos without orthorectification are not sufficient for precise dimensioning.
- Unclear units/coordinates: Missing documentation (m/mm, local vs. global coordinate system) creates downstream errors.
- Over-/under-resolution: The wrong scan density either misses details or inflates file sizes. It should be aligned with the intended purpose.
Facade survey vs. area measurement survey
- Area measurement survey: Focuses on gross/internal floor areas according to defined standards, e.g. DIN 277.
- Facade survey: Focuses on vertical building envelope surfaces, openings, details and facade elevations for planning and renovation according to suitable measurement rules.
FAQ
What Accuracy Is Typical for a Facade Survey?
With TLS, millimetre to low-millimetre accuracy is realistic. Photogrammetry delivers centimetre-accurate facade elevations, depending on the camera, GCPs and calibration.
When Should I Use Drone Photogrammetry?
For high, hard-to-access facades or large-scale projects. Orthophotos and facade elevations accelerate planning and quantity take-off.
Which Formats Should I Request?
Point clouds (E57/LAS/LAZ), orthorectified facade images (GeoTIFF/JPG + world file), 2D plans (DWG/DXF/PDF) and optionally IFC, each with metadata covering version, units, coordinates and tolerances.