Prague is full of panel buildings, and each one has flues that function as ventilation or exhaust for combustion gases. The topic of chimneys in panel buildings is more complex than it appears. Different rules, different responsibilities, different problems.
Let us break this down.
Are there chimneys in the apartment block?
Yes: but most of them serve as natural ventilation ducts, not as a flue for heating. In a typical apartment block flat you will find vents in the kitchen (for the extractor hood or natural ventilation) and in the bathroom/toilet.
In some older panel buildings (1970s–80s), the original gas supply lines and flues for gas stoves or boilers have been preserved. Today these appliances are used less frequently, but the flues remain in place.
Three types of ventilation ducts in a panel building
1. Ventilation ducts (WC, bathroom)
They extract air from rooms. They usually discharge onto the roof or connect to a central ventilation shaft. Regular inspection and cleaning are a legal requirement, but not for the flat owner, rather for the building's owners' association. The building's owners' association or the house owner.
2. Flues for gas appliances (boiler, water heater)
If you have a gas boiler or an instantaneous water heater with flue gases vented through a duct in your flat, you are required to have the flue path regularly cleaned and inspected. 1× a year. This obligation rests with you as the flat user.
3. Unused flues
Older flues for gas stoves or ceramic heaters are often bricked up or left unused. Their condition should be addressed by the building's owners' association.
Who is responsible for what in a panel building?
This is a key question. Responsibility depends on whether it concerns part of the flat or a common area of the building.
- Flue path of your gas boiler - your responsibility: you must ensure annual cleaning and inspection
- Shared ventilation ducts - liability of the building's owners' association or the house owner
- Roof terminations for ventilation ducts - The building's owners' association or the house owner
Tip for tenants: If you are a tenant, the obligation depends on the wording of the tenancy agreement. If the agreement is silent, the owner (landlord) is usually responsible. I recommend clarifying this in writing.
Most common flue problems in panel buildings
Backdraft: air blows from the flue into the flat
A classic problem in older panel buildings. The ventilation duct intended to extract air instead draws it in, especially in winter. The cause is usually:
- Overpressure in the shaft (other flats ventilate better)
- Blocked flue or blocked roof terminal
- Malfunctioning ventilation component
Spread of odours between flats
Ventilation ducts connect flats throughout the entire height of the building. Unsealed or damaged ducts allow odours (cooking, tobacco) to migrate between flats. The solution involves sealing the air inlet and, where necessary, installing backdraft dampers.
Forgotten and blocked flues
During flat renovations, flues are sometimes bricked up or covered by furniture. However, if the flue remains functionally connected, covering it can cause problems for both you and your neighbours.
Do you have doubts about the condition of the flue or exhaust gas passage in your flat? I will come and assess. I also work in apartment blocks in Praha.
Call 277 278 918Do you want to install a fireplace or stove in an apartment block?
Technically possible but demanding. A panel building usually lacks flues sized for solid fuels. Installing a fireplace stove requires:
- Project and building authority permit
- SVJ consent
- Construction of a new flue gas duct (either a new shaft or lining an existing flue).
- Inspection of the new flue gas path before commissioning
Without meeting these conditions, stoves cannot be legally operated in a flat within a panel building.
When to call a chimney sweep for a block of flats?
You need a chimney sweep if:
- Do you have a gas boiler or water heater with flue gas extraction (mandatory once per year)?
- Do you smell exhaust fumes or gas in your flat?
- The air vent blows back into the flat.
- Installing a new gas appliance (mandatory inspection)
- Planning a stove or fireplace (assessment required)