Daylight factor assessment in an existing flat after construction of an adjacent building. The report demonstrated a drop below the limit required by ČSN 73 0580.
The owner of a flat in Pilsen contacted me after construction of a neighbouring building, which in their view significantly shaded the living rooms.
Assessment
I calculated the daylight factor (DF) in two scenarios — pre-construction (reconstructed from documentation) and post-construction (with a measured 3D model of surroundings).
Result
DF in living rooms dropped:
- Living room: 1.2 % → 0.6 % (limit 0.9 %)
- Bedroom: 1.0 % → 0.5 % (limit 0.7 %)
The report demonstrated that ČSN 73 0580 requirements are not met and was used as evidence in the administrative proceedings.