A 30-minute technical inspection of a flat

A phone with a torch and a charger (for testing sockets), a tape measure of at least 5 m, a small spirit level — optional but useful for checking the floor and the windows. A sheet of paper and a pen for notes.

Ideally daytime, with good light. Evening lighting hides stains and damp. If only an evening viewing is offered, ask for a second visit during the day; a refusal is suspicious.

First, inspect the corners of the ceiling and the floor along the walls. Yellowish or brown marks are signs of a leak from above or of mould. One freshly painted corner in an otherwise old finish is suspicious — they may be painting over a recurring problem.

Musty, damp or chemical smells are cause for caution. Fresh paint can also mask things: ask to air the flat and come back in 15 minutes. If the smell returns, there is a problem with ventilation or plumbing.

Roll any round object (a pen) across the floor. If it rolls by itself, the slope is serious: either a poor refurbishment or a structural problem.

Close and open every window; check for a draught around the frame. Condensation between panes means the sealed unit has failed and replacement is expensive. In winter such windows = a cold flat and high heating bills.

A double door or a good lock is the safety standard. Ask whether the lock has been changed and who might know about the previous keys. On move-in it is better to swap the lock cylinder.

Turn on cold and hot water simultaneously in the kitchen and bathroom. If the pressure drops sharply, there is a pipe problem. Flush the WC and at the same time watch the basin: the water should drain quickly and without gurgling.

Plug a phone charger into 3–5 sockets in different rooms. A flickering indicator lamp or a charger that heats up means old wiring. Not a blocking issue, but a reason to ask for a discount or a replacement.

Glance into the distribution board on the landing. Modern circuit breakers are fine. Old fuses or twisted wire splices on the floor are serious: under overload such a flat catches fire easily.

Measure 1–2 rooms with the tape and compare to the declared area. If the actual area is 5 m² less, ask questions and do not buy or rent at the same price. The discrepancy often comes from a balcony or an unapproved alteration.