Bathroom Mirrors and Medicine Cabinets

The mirror is where you spend most of your time in a bathroom, and the medicine cabinet is often the only closed storage at eye level. Both look simple, but the good versions depend on decisions made inside the wall: whether there is room to recess a cabinet, where the power goes for lights and defoggers, and where the blocking sits for a heavy mirror. This page covers sizing, lighted and defogging mirrors, recessed and surface cabinets, and what to check before you buy.

Sizing the mirror to the vanity

Start with the vanity and work up. The mirror should relate to the sink and faucet below it and to the lights beside or above it. These are designer guidelines, not code, but they are the ones most bathroom designers use.

• Width. Keep the mirror within the width of the vanity, and center it on the sink rather than on the cabinet if the sink is off center.
• Bottom edge. Set it high enough to clear the faucet spout and any backsplash, so water does not splash the glass every time you wash.
• Top edge and height. The mirror should show the face of the tallest regular user and the shortest. A taller mirror solves both.
• Double vanity. Two mirrors, each centered on a sink, leave room for a sconce or a tall cabinet between them. One wide mirror makes a small room feel larger.
• Room for lights. If sconces go beside the mirror, the mirror width has to leave space for them within the wall. Plan the mirror and lights together.

The vanity side of this, including common widths and heights, is on our vanity sizes and heights page. For how light should fall on your face, see bathroom lighting.

Mirror types compared

Lighted and defogging mirrors

A lighted mirror is a light fixture as far as the electrical code is concerned, so it needs a power supply in the right spot behind the glass. Some plug into a receptacle hidden behind the mirror; most premium models are hard-wired to a junction box. Either way the box location comes from the mirror's installation drawing, which means choosing the mirror before the electrical rough-in.

• Light quality. Compare the color temperature and the color rendering index (CRI) on the spec sheet. Light that renders color poorly makes makeup and shaving harder.
• Dimming and switching. Built-in touch switches are convenient, but a wall switch or dimmer is easier for guests. Decide which controls the light, and do not let two switches fight each other.
• Defoggers. A heating pad behind part of the glass keeps that area clear after a shower. Many lighted mirrors include one, and stand-alone pads are made for ordinary mirrors. A defogger helps, but it is not a substitute for a fan that actually removes the moisture; see choosing a bathroom exhaust fan.
• Near a tub. Washington's electrical rules (WAC 296-46B-410) require luminaires within an enclosed shower area or within five feet of the waterline of a bathtub to be enclosed unless listed for that use, with GFCI protection where they have exposed grounded metal parts. If a lighted mirror will be close to the tub, check its listing. The full picture is on our bathroom electrical code page.

Mirrors near a tub or shower: safety glazing

Glass near a tub or shower can fall in a hazardous location under the Washington residential code (R308.4.5), and glass mirrors in hazardous locations must pass the safety glazing impact test. The code makes an exception for "mirrors and other glass panels mounted or hung on a surface that provides a continuous backing support" (R308.3, Exception 2). A mirror fully bonded to a flat wall usually falls under that exception; a mirror hung on clips with an air gap behind it, or a mirrored door, may not. If a mirror will sit beside a tub or inside a shower area, ask your contractor or the inspector before ordering. Our page on safety glass rules explains the hazardous-location measurements.

Medicine cabinets: recessed or surface-mounted

A recessed medicine cabinet sits inside the wall cavity, so only the door and a thin frame project. A surface-mounted cabinet hangs on the wall like a mirror. Recessed is neater and keeps the cabinet clear of the faucet and your head, but only where the wall allows it.

Which walls cannot take a recessed cabinet

• The plumbing wall. The wall behind the sink usually carries the drain, the vent and the supplies. A cabinet cannot share the bay with a vent pipe.
• Walls with ducts or wiring. A fan duct, a heating duct or a run of cable in the bay has to be rerouted, which is only practical with the wall open.
• Exterior walls. A recessed box takes the place of insulation in an outside wall. When exterior wall cavities are opened during a remodel, Washington's energy code expects them to be filled with insulation (WAC 51-11R-50300, R503.1.1). A cabinet in that bay leaves a cold spot that can collect condensation in a damp Northwest winter. A side wall or an interior wall is the better place.
• Shared walls in condos and townhomes. A wall between units may be part of a fire separation. Do not cut into it without the association's and the building department's approval; see remodeling in a condo or townhome.
• Load-bearing walls. A cabinet wider than one stud bay means cutting a stud and adding a header. In a bearing wall that is structural work to be designed and permitted.

Features to compare in a cabinet

• Door count and hinge side. One door suits a single sink; two or three doors suit a wider vanity. A door that swings into a sconce or a wall is a common mistake.
• Mirrored interior and side panels. Interior mirrors give a second view; mirrored sides on a surface cabinet look finished from an angle.
• Shelves. Adjustable glass shelves hold up to humidity better than painted particleboard.
• Soft-close hinges and magnetic strips for small metal items.
• Box material. Aluminum or other moisture-tolerant boxes resist swelling better than raw particleboard in a steamy room.

What to check before you buy

1. Mirror or cabinet width against the vanity, the sink centerline and any sconces planned beside it.
2. The bottom edge clears the faucet and backsplash.
3. For a recessed cabinet: the rough opening size and depth, and confirmation that the chosen stud bay is empty, interior and not part of a shared or bearing wall.
4. For a lighted mirror: whether it is hard-wired or plug-in, the junction box position on the installation drawing, color temperature, CRI and dimming, and its listing if it will be within five feet of a tub.
5. For any mirror near a tub or shower: whether it will be fully backed or needs safety glazing.
6. Weight and mounting method, so blocking goes in before drywall.
7. Edge treatment or backing made for humid rooms.
8. Door swing and hinge side against nearby lights, walls and the shower door.

How JDI plans mirrors and cabinets

On our bathroom projects we choose the mirror or medicine cabinet during design, so the stud bay, blocking and power are set during framing and rough-in rather than discovered afterward. The 3D design layout shows the mirror, lights and vanity together before anything is ordered. To see how a full bathroom project runs, visit our bathroom remodeling service in Vancouver page or book a free in-home consultation.