Before any fixture is ordered, the rough-in—the plumbing and electrical points already fixed in the walls and floor—is verified against the fixture that has been chosen. The rough-in is permanent. The fixture chosen has to fit what is already there, or walls have to be opened and reconfigured. A toilet set for a 30-centimetre rough-in cannot be made to work at a 38-centimetre rough-in. Checking the actual rough-in position against the fixture specification before ordering prevents expensive adjustments later. This is done with the walls and floor still open, before finishes close over the rough-in positions.
The order that fittings go into the room matters. Some go on early; some go on last. The basin might go in after the wall is tiled but before painting, because access to plumbing is still needed. The mirror and wall-mounted lights go on after painting, when the walls are finished. The toilet and floor-mounted fixtures go on after flooring is done. Plumbing final connections happen after the toilet is set. The sequence anticipates what needs access and what can wait until surfaces are finished.
A set of fittings that are coordinated—vanity, mirrors, sconces, towel rails—has to be installed together so elements are consistent with one another. Heights are aligned; finishes match or contrast as intended; the whole arrangement reads as designed rather than assembled from pieces. This consistency matters when pieces are ordered separately or come together from different phases of the work.
Handling a finished fitting against a finished surface is where damage happens most often. The last stage of installation—bringing a fixture through the finished room and setting it in place—is the point where scratches and marks occur. Care in movement, protection of both the fixture and the surfaces it passes through, and gentle setting prevent the small damage that adds up to looking careless.