5 Warning Signs Your Prague Apartment Needs Attention

Prague winters are relentless on window seals. If you feel a slight breeze while the windows are closed, or if you notice condensation trapped between the panes of glass, your thermal envelope is compromised.

In older buildings (činžáky), the original double-box windows often suffer from wood rot or poor fitting. In new builds, it's usually the rubber gaskets that have perished. Ignoring this leads to a "Heating Tax" — where 20% of your energy bill is simply leaking into the street.

If you notice a dark tint in the upper corners of a room or behind large wardrobes, it is rarely just dust. In the Prague climate, this is the first stage of mold growth caused by a thermal bridge.

This often happens after a renovation where new windows were installed without upgrading the ventilation. The apartment becomes "too airtight," trapping humidity. If your bathroom fan sounds like a jet engine but the mirror stays foggy for 20 minutes after a shower, your ventilation is failing.

Prague's subsoil, particularly in areas like Libeň, Vysočany, or the slopes of Vinohrady, can lead to subtle building settlement. While tiny "spider-web" cracks in plaster are often cosmetic, diagonal cracks starting from the corners of door frames or windows are a signal of movement.

If a door that used to close perfectly now sticks or scrapes the floor, the "Technical Organism" of the building is shifting. This needs a technical baseline to determine if the movement is historic or active.

If your shower pressure drops when a neighbor flushes, or if you hear a "thumping" sound (water hammer) when you turn off a tap, your plumbing system is under stress.

In older Prague districts, many buildings still have aging horizontal distribution pipes. Fluctuating pressure often points to a failing pressure-reducing valve or a buildup of limescale and sediment. Left unchecked, this pressure stress is the primary cause of burst pipes behind tiles — the most expensive "surprise" a landlord can face.

For those owning ground-floor or "-1 floor" units (popular in Prague's hilly terrain), the sokl — the lower exterior edge of the building — is your first line of defense.

If you see peeling paint or "salty" white deposits (efflorescence) on the interior walls near the floor, the building's horizontal moisture barrier has likely failed. In Prague's older brick stock, ground moisture can travel up the walls through capillary action, destroying the value of your renovation from the inside out.