What a new-build site leaves behind
A new house changes hands several times before it reaches you: site manager, plasterer, kitchen fitter, landscaper. That is why many builders supply a temporary cylinder, or a system in which the owner's first key cancels the one used during construction. You still need to know which one you have: that question belongs at the handover, not three years later. If nothing in your file says so, replacing the cylinder when you arrive remains the simplest precaution, and it touches neither the door nor the mechanism.
The same reasoning applies to buying a ten- or fifteen-year-old house, which happens often here now that the recent housing stock is starting to turn over. You inherit the spares cut by the previous occupants, sometimes a set left with a neighbour or a maintenance company. On these doors, changing the cylinder alone is almost always enough: the dimensions are measured on site — spindle position, length either side, thickness of the door leaf — because a cylinder that protrudes offers a needless grip. The multipoint mechanism itself stays where it is if it works properly.
One key ring per plot: front door, garage, side gate, garden shed
On an estate plot, the front door is only one way in among several. Add the side door of the attached garage, the side gate onto the street, sometimes the pool plant room or the shed at the bottom of the garden. Each was fitted by a different trade, with its own key: the key ring grows and, for want of anything better, one key ends up under a plant pot. A master key system restores order by making several cylinders work with the same key, with the level of protection chosen entry by entry.
Outdoor openings also call for mechanisms that can cope with the air off the Bassin. A side gate cylinder facing straight into the wind, a shed padlock near the canal or the lock on premises at one of the ports do not age like a sheltered landing door: they clog, they seize, and eventually they break a key at the worst possible moment. Fitting parts designed for outdoor use at the time of replacement, then servicing them once a year, takes far less effort than redoing the lot in poor conditions in the middle of winter.
How does this service work?
Techniques, typical situations, standards and things to watch out for: it is all on our lock and cylinder replacement page. This page focuses on what the service involves in Gujan-Mestras.