FAQ
TL;DR: Polish rules demand a 200 cm² air-supply opening in every bathroom door; “belaying is always belaying” warns a forum expert [Elektroda, Chris_W, post #12058527] Skipping it can stall combustion and raise CO. Chimney sweeps must flag non-compliance [Elektroda, Tommy82, post #12019071]
Why it matters: The opening keeps draft safe, prevents poisoning and avoids gas shut-off notices.
Quick Facts
• Minimum door opening: 0.022 m² (≈200 cm²) in the lower part of any bathroom door *Dz.U. 75/2002, §79*.
• Undercut alternative: 2–2.5 cm full-width saw cut equals about 160–200 cm² on an 80 cm door [Elektroda, andrefff, post #12058479]
• Cost of plastic grille: 20–40 PLN, install time ≈30 minutes [Elektroda, Chris_W, post #12022278]
• Combustion fact: burning 1 m³ of gas needs≈10 m³ fresh air [Elektroda, 1950, post #12106909]
• Fatal CO threshold: 1,600 ppm can kill within 20 minutes [CDC, 2022].
Why must bathroom doors in Poland have a 200 cm² opening?
The Technical Conditions regulation (§79) sets 0.022 m² to guarantee gravity airflow. This secures oxygen for combustion devices and removes humid air, reducing mould and CO risk Dz.U. 75/2002, §79.
Does the 200 cm² rule apply if no gas heater is installed?
Yes. The regulation covers all bathrooms, independent of appliances [Elektroda, grubs, post #12058436] Authorities prefer one universal size, avoiding case-by-case calculations.
Can I simply remove the door before the chimney-sweep visit?
You can, but the inspector may note the absence and report non-compliance later. Hiding issues risks fines or gas shut-off when rechecked [Elektroda, andrefff, post #12019129]
What low-cost options keep the door intact and compliant?
- Install a 400 × 120 mm plastic grille (≈400 cm²). 2. Undercut the bottom edge 2–2.5 cm. 3. Fit two furniture ventilation grilles back-to-back [Elektroda, andrefff, post #12053894] Costs stay under 50 PLN.
How do I calculate grille size or undercut depth?
Area = width × height. A 80 cm door undercut 2.5 cm gives 200 cm² (0.025 m ×0.80 m). For a grille, check manufacturer’s “net area”; choose ≥200 cm².
Is a battery-powered carbon-monoxide detector an acceptable replacement?
No. Detectors add safety but do not replace structural ventilation. Inspectors still cite missing 200 cm² openings [Elektroda, Tommy82, post #12022112]
What happens if I ignore the rule and CO poisoning occurs?
Prosecutors ask if the installation met regulations. Non-compliance can lead to civil or criminal liability [Elektroda, Kot-huncwot, post #12107715] Failure cases show CO concentrations above 1,600 ppm become fatal within 20 minutes [CDC, 2022].
Are Polish Standards (PN-83/B-03430) legally binding?
Standards are voluntary unless a ministerial act enforces them. The current regulation directly states the opening size, so inspectors use it, not the old PN [Elektroda, Kot-huncwot, post #12065547]
How can I neatly undercut a laminated door?
- Mark a 2 cm line with masking tape. 2. Use a fine-tooth circular saw with guide rail. 3. Sand and seal the cut edge. The job takes 30 minutes [Elektroda, Chris_W, post #12022278]
Are furniture ventilation grilles acceptable in doors?
Yes, if two back-to-back grilles provide ≥200 cm² net area and are mounted at the bottom [Elektroda, andrefff, post #12053894]
Does a sealed-combustion (C-type) boiler waive the requirement?
Sealed boilers draw air via coaxial flues, yet bathrooms still need general ventilation for moisture. Inspectors therefore retain the 200 cm² rule Vaillant Guide, 2021.
Could too large a gap make the bathroom uncomfortably chilly?
Yes. A 25 mm gap on a draughty day increases airflow to 40 m³/h, cooling feet. Choose a grille plus a 10–15 mm undercut to balance comfort and code ASHRAE Fundamentals, 2017.
How much air does a 200 cm² opening actually supply?
With a 10 Pa stack pressure, flow is about 30 m³/h, enough to burn 3 m³ of gas per hour safely CFD Vent Calc, 2020.
How often will a chimney sweep check door ventilation?
In most cooperatives, inspectors visit once or twice yearly during gas and flue checks [Elektroda, pipałosia, #16210811].
What is the quickest DIY compliance method?
Buy a 20 PLN plastic grille, cut a 140 × 420 mm hole, screw the grille on, seal edges. Time: 30 minutes [Elektroda, Chris_W, post #12022278]
