The mirror size is not the rough opening

Start with the installation drawing. The visible door, cabinet box and rough opening can all have different dimensions. Also check the flange that covers the wall cut and the space needed for hinges to swing. A door that fits neatly between two sconces while closed can still hit one when opened.

Kohler’s cabinet instructions distinguish the cabinet’s mounting and installation requirements. Work from the model-specific rough opening and fixing details, rather than buying a cabinet on mirror width alone. Kohler: Medicine cabinet installation instructions.

Can this wall accept a recess?

  • Clear suitable cavity

    Coordinate the required framing, box depth and finished opening.

  • Pipes or electrical services

    Price relocation before cutting; surface mounting may avoid it.

  • Exterior or protected assembly

    Review insulation, air sealing and assembly requirements first.

  • Door collision

    Change the position, hinge arrangement or cabinet format.

Find out what the wall is doing

A stud detector is useful, but it does not certify a cavity free of pipes and wires. Review renovation photographs and inspect through an appropriate existing opening where possible. Have a qualified person assess concealed services before making an exploratory opening. Do not cut a stud because the box is almost wide enough.

An exterior wall also carries insulation and air-control layers. Recessing a deep metal cabinet can take away space those layers need and create a cold surface. A wall between units may have fire or sound requirements. Those assemblies need a proper detail; a bead of caulk around a cabinet is not a substitute.

Check the whole grooming area

Mark the mirror, cabinet body, faucet and light positions with tape. Test visibility for the people using it and the door’s full swing. Think about the shelf depth needed for actual bottles; the prettiest narrow cabinet is less useful if every bottle must lie sideways.

Confirm how an illuminated cabinet will receive power and remain serviceable before wall work. New electrical work belongs with a licensed electrical contractor. If the wall is unsuitable, compare a shallow surface cabinet with a plain mirror and separate storage. For tall fixtures, check vessel-sink height so the cabinet does not create the next collision. ESA explains how to verify a licensed contractor.