What data an energy audit requires
An energy audit — whether for an energy performance certificate (EPC), a renovation roadmap, or a subsidy application — requires a specific set of building data. The quality of the audit depends directly on the accuracy of this data.
| Data point | Why it is needed | Typical source |
|---|---|---|
| Floor plan (all floors) | Base geometry for all calculations | Manual measurement or LiDAR scan |
| Room areas (m²) | Heated floor area for energy demand calculation | Derived from floor plan |
| Room volumes (m³) | Ventilation and heating load calculations | Derived from floor plan + ceiling height |
| Wall areas (m²) | Thermal envelope calculation | Derived from floor plan + wall height |
| Window and door positions | Thermal bridge and solar gain calculations | On-site survey |
| Ceiling heights | Volume calculations and HVAC sizing | On-site measurement |
All of this data starts with the floor plan. A floor plan that is inaccurate by 5% produces energy demand calculations that are inaccurate by a similar margin — which can affect subsidy eligibility and renovation recommendations.
How energy consultants currently collect building data
Most energy consultants use one of two approaches for building documentation: they request existing plans from the building owner, or they measure on-site with a tape measure or laser distance meter.
Existing plans are often unavailable, outdated, or inaccurate. Buildings renovated after original construction rarely have updated drawings. For older residential buildings, plans from the 1960s to 1980s frequently contain errors or do not reflect the current state.
On-site measurement with a tape measure or laser distance meter takes 2 to 4 hours for a 3-room apartment, including manual entry into a spreadsheet or energy software. For a multi-unit building with 10 apartments, that is 20 to 40 hours of documentation time before the audit work begins.
LiDAR scanning workflow for energy documentation
LiDAR scanning with iPhone Pro or iPad Pro captures all required building data in a single on-site visit. The scan produces a dimensioned floor plan, room areas, room volumes, ceiling heights, and wall areas automatically — all exported to Excel or PDF without manual data entry.
| Step | What you do | Time |
|---|---|---|
| 1. Open Metaroom | Open the app on iPhone Pro or iPad Pro and create a new project for the building. | 30 seconds |
| 2. Scan each room | Walk through each room slowly. The LiDAR sensor captures walls, floor, and ceiling geometry continuously. No individual measurements needed. | 2 to 4 minutes per room |
| 3. Connect rooms | Walk through doorways to stitch rooms into a complete floor plan per floor. | Included in scan time |
| 4. Add photos | Photograph windows, doors, heating system, insulation, and any visible building defects directly in the Metaroom Snapshot feature. Photos are linked to room positions in the floor plan. | 5 to 10 minutes |
| 5. Export | Export room data to Excel (areas, volumes, dimensions) and floor plan to PDF. Both files are ready for energy assessment software. | 1 minute |
Total on-site time for a 3-room apartment: 15 to 30 minutes including photos. For a 10-apartment building: 3 to 5 hours instead of 20 to 40. No return visits for missed measurements. No manual data entry.
Export formats for energy software
Metaroom exports building data in the formats that energy assessment software requires.
| Export format | Content | Use in energy workflow |
|---|---|---|
| Excel (XLS) | Room names, areas (m²), volumes (m³), ceiling heights, wall lengths | Direct input into energy assessment software and calculation spreadsheets. Compatible with Kaiser EDV. |
| PDF (2D floor plan) | Dimensioned floor plan with room labels | Attached to energy certificate documentation and subsidy applications |
| PDF (project report) | Complete building survey including floor plan, room data, and photos | Client handover document and audit record |
| IFC | Full 3D building model with room metadata | BIM-based energy simulation software |
Metaroom's Snapshot feature lets you attach photos to specific positions in the floor plan during the scan. Photograph the heating system, insulation visible in the attic or basement, window frame conditions, and any thermal bridges. The resulting project report contains floor plan, room data, and photos in a single PDF — ready to attach to subsidy applications or share with clients without additional preparation.
Accuracy requirements for energy documentation
Energy audits typically require floor area accuracy of 1 to 5%. LiDAR scanning with iPhone Pro or iPad Pro delivers accuracy within 1%, typically 1 to 2 cm per wall. Room area calculations are typically within 1 to 2 m² of the actual figure for a standard apartment.
This is more than sufficient for energy performance certificates, renovation roadmaps, and subsidy applications under GEG (Gebäudeenergiegesetz) and comparable European regulations. A 1% area deviation produces a proportionally small effect on energy demand calculations, well within the accepted tolerance ranges for regulatory documentation.
Documenting multi-unit buildings
For apartment buildings with multiple units, LiDAR scanning scales efficiently. Each apartment is a separate scan project. Scans for an entire floor can be completed in 30 to 60 minutes. A 10-apartment building takes 3 to 5 hours on-site — including photos — compared to 20 to 40 hours with tape measure and manual entry.
Each apartment produces its own Excel export with room data and its own PDF floor plan. The Metaroom Workspace allows all scans for a building to be managed in a single project, with individual exports per unit or a combined report for the full building.
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, room areas, volumes, and ceiling heights, exportable to Excel, PDF, IFC, and 30+ other formats. A 3-room apartment scans in under 20 minutes. The Snapshot feature links photos to room positions for complete audit documentation.
