What to bring to a viewing of a commercial space, what to do there in 20 minutes, and what to ask the landlord. Cheap meters and phone apps give indications, not certified readings: use them to decide what to ask and what to have checked by a professional.
What to buy (~€130–180)
- Laser distance meterLength, width and ceiling height in seconds.€25–40
- NDIR CO₂ meter with temperature and humidityHow stale the air gets. NDIR sensors measure CO₂; cheap “eCO₂” ones only estimate it.€50–80
- Clip-on light (lux) meterDaylight at the counter and at the back.€15–25
- Moisture meterDamp in walls, especially low down and in the cellar.€15–25
- Infrared thermometerCold glass and outside walls: draughts and heat loss.~€20
- Torch, tape measure, an A4 sheet, a bottle of waterDark corners, a second measurement, a scale for photos, a drain test.on hand
Rough 2026 prices, not quotes.
General orientation, not legal advice.
Phone apps
- –NIOSH SLM (iOS) Sound level in dB.
- –phyphox Accelerometer for vibration, compass for the facade direction.
- –BNetzA Mobilfunk-Check Mobile signal and speed test.
- –A spirit-level app Sloping floors and counters.
- –Camera + the A4 sheet Put the sheet in the photo as a scale.
General orientation, not legal advice.
The routine (20 min, in this order)
1Outside2 min
- Photograph the facade from across the street.
- Note which way the facade faces (compass).
- Step or threshold at the entrance; door type.
2Doorway2 min
- Photograph into the space from the door: can you see the counter from the street?
- Feel for a draught; measure the door width.
3Geometry3 min
- Length, width, ceiling height in two places.
- Top of the windows and their sizes.
- Photos back towards the door, the windows, the ceiling and the floor, with the A4 sheet in view.
4Sound2 min
- Clap in the centre and in a corner: how long does it ring?
- Background noise with the door closed, and while a tram or bus passes.
- Vibration on the floor (phyphox).
5Air2 min
- CO₂, temperature and humidity (CO₂ only says much with people in the room).
- Infrared on the glass and on the outside walls.
- Smell the corners.
6Condition3 min
- Damp at the bottom of the walls (moisture meter).
- Torch behind equipment and in the cellar: damp, salt marks, droppings.
7Services3 min
- Water supply and drainage.
- Fuse box: open its door and read the main-fuse label. Look, don't touch.
- Gas meter; the extraction shaft, if there is one.
- Pour water into the floor drains: does it run away?
8Back of house2 min
- WC, storage, cellar.
- WC door width and room to turn around.
9Connectivity1 min
- Speed test at the counter and at the back.
General orientation, not legal advice.
12 questions for the landlord
- 1What was the last permitted use of the space, and is there a permit for it?
- 2Can an extraction duct run up above the roof, and is that allowed?
- 3Main fuse size, three-phase power, gas?
- 4Is there a grease separator (Fettabscheider), or an exemption from the Berliner Wasserbetriebe (BWB)?
- 5Is the building listed (Denkmal)? Rules for the facade and signs?
- 6The energy certificate and the service-charge statements (Nebenkostenabrechnungen) for the last two years?
- 7What heating is there, and who controls its hours?
- 8Are there flats above? Any past complaints about noise or smells?
- 9Any history of damp, flooding or pests?
- 10Are the cellar and storage included? Is the WC shared?
- 11Where is the second exit?
- 12Can I come back during business hours, at the busiest time?
General orientation, not legal advice.