How to light a kitchen, bathroom and home office

Task light in front of the person, under-cabinet light, even light on a face at the mirror, a desk without screen glare, and a test for each work surface.

1. Task light starts where you stand Understand

Task light is the layer aimed at the surface where the work happens. Its job in a work room is simple to state: light on the surface, from a direction your head, hands and body do not block. A light behind you puts your shadow on the work. A light in front of you and slightly to one side lights the work and leaves the shadow behind. Physical principle The Lighting Research Center's kitchen guidance for older adults puts it as a placement rule: luminaires over the sink, stove and counters, slightly to the side of and in front of where a person stands, and not only one ceiling fixture in the center of the room, which casts the person's shadow onto the counter or sink (LRC, Lighting Rooms: Kitchen, an archived copy of a page the Lighting Research Center no longer hosts).

Distance does the rest. The inverse-square law (How light works in a room) says that halving the distance from a small source to the surface gives about four times the light. A task light a foot above the counter or beside the page does more than a ceiling fixture eight feet away, with a fraction of the lumens. That is why the lumen calculator's whole-room figure for a task level is so large, and why this manual's answer for a work surface is a task light and a reading, not more ceiling light.

Published targets for work surfaces

The published targets differ, as they did in Survey and test your rooms. Use them to compare your readings, not as a pass mark.

The first column is from the Defense Department's housing criteria (UFC 3-530-01, section 3-9); the second is Penn State's energy course table (Penn State EGEE 102), commonly cited and attributed to older IES guidance with no edition named. Convention For older eyes the Lighting Research Center's floor for tasks is higher again (Survey and test your rooms). Your before and after readings, with the same device in the same spot, are what this chapter asks for; a phone gives a comparison, not a light level.

2. Kitchens

A kitchen has general light to move around by and task light on the counter, sink and stove. The two do different jobs. The LRC's guidance, the Defense Department's switching pattern and the DOE's under-cabinet brief agree on the shape:

• Under-cabinet light for the counters. The LRC places it under the upper cabinets, hidden from view. A Department of Energy brief on under-cabinet lighting says its first job is light on the work surface directly beneath, and its second is light on the backsplash and nearby areas, to reduce the contrast between light and dark (DOE, Residential Undercabinet Lighting with LEDs). The brief's products are from 2008; the principle stands.
• A light over the sink. The LRC puts a downlight over the sink and calls it especially important when general light comes from one fixture in the center of the ceiling.
• Light over the stove. Many range hoods have their own light; it counts as the stove's task light.
• Uplight from the cabinet tops, where there is space. If there are 12 to 18 inches between the cabinet tops and the ceiling, the LRC suggests light on top of the cabinets, with the tops painted matte white, bouncing off the ceiling as glare-free general light.
• Separate switches. The Defense Department criteria give task light over the sink or work surfaces its own switch. In California, for example, the 2025 code as the City of Roseville summarizes it switches under-cabinet light separately from ceiling light (Roseville, 2025 lighting measures); your building department sets the rules where you live. Ask the authority

A grid of recessed downlights is general light. A downlight behind where you stand at the counter casts your shadow forward, the same way the LRC's single central fixture does, so a grid alone tends to leave the counters shadowed at the moment you work at them. Physical principle The counter is lit by the task layer. Recessed downlights in an insulated ceiling also raise IC and airtight questions; those are in Layers, fixtures and glare and the brief.

No wiring is needed for the first version. Plug-in and battery under-cabinet lights stick or screw under the cabinet. A renter asks the landlord in writing before attaching anything (Working with an electrician).

What a counter reading looks like

PNNL measured counters in demonstration homes in 2008 (PNNL, Lane County demonstration). Measured horizontally at counter height, an LED under-cabinet fixture gave 35.8 fc against 13.4 fc (low setting) and 53.4 fc (high setting) for a halogen unit. They also reported uniformity as a ratio of the highest reading to the lowest: 7.0 for the LED and 10.8 for the halogen. The products are dated; the method is the point. Take a reading at the front edge of the counter where your hands work, at the sink and beside the stove, and note the highest and lowest. A big ratio means bright stripes and dark gaps.

Color for food and faces

The Defense Department criteria recommend 2700 K for homes, no interior source above 4100 K, CRI 80 or more everywhere, and for kitchens either a TM-30 fidelity (Rf) of at least 80 with gamut (Rg) between 97 and 110, or CRI 90 or more with a minimum R9. Convention California's JA8 qualification asks for CRI 90 and R9 of 50 or more, as one state's rule (Energy Code Ace, JA8 2025). Bulbs, labels and color explains the measures (color rendering). The DOE color fact sheet's advice applies: there is no substitute for looking (DOE, LED Color Characteristics). Put a tomato, a lemon and a raw chicken breast or a piece of salmon under the light you are trying; if they look as you expect, the bulb passes your test. Test it

Pendants over an island

Pendant heights are conventions. The one fetched source is a practitioner publication about dining tables: Hunker gives 30 to 34 inches from the tabletop to the bottom of the fixture for an 8 ft ceiling, and says designers disagree about taller ceilings, some keeping the same range and others adding 3 inches per extra foot (Hunker, The Height of a Light Over a Dining Table). Preference We found no free source for island pendants; the same range is a starting point to test. Hang a cardboard mock-up at the planned height, stand and sit at the island, and check two things: you can see across without the pendant in your eyes, and nobody seated sees a bare bulb. The mock-up settles it.

3. Bathrooms

The bathroom task is a face at the mirror. The LRC's bathroom guidance says the light should be bright, uniform and shadow-free while minimizing glare, and that faces lit from all sides have few shadows (LRC, Lighting Rooms: Bathroom, an archived copy of a page the Lighting Research Center no longer hosts). It describes two ways to get there:

• Light on both sides of the mirror, where there is room. Side light reaches under the brows and the chin.
• A vanity light that bounces off the ceiling, with a white countertop and light walls, so light arrives from several directions. The LRC adds that a matte, light-colored counter reflects light to the underside of the chin.

A single downlight over the mirror lights the top of the head and casts shadows under the eyes, nose and chin. Physical principle The no-wiring version is a lamp beside the mirror on the counter, kept dry and away from the sink, with the bulb shaded.

A night setting. The LRC describes a separately switched shower light as a gentler middle-of-the-night option, and the IES consumer guide for older adults suggests dimming the bathroom at night so the eyes do not have to readapt to the dark bedroom (IES, Lighting Your Way to Better Vision, a copy hosted by the Center of Design; the guide derives from IES RP-28-20, since revised as RP-28-25). The night path is Living rooms, bedrooms and stairs.

Damp and wet markings

Fixture boxes and labels carry a location marking. H.E. Williams, a fixture maker, reprints the electrical code's and the UL 1598 listing standard's definitions side by side (H.E. Williams, Dry, Wet, and Damp Locations). In that reprint:

• A damp location is protected from weather and not subject to saturation, but exposed to moderate moisture (a roofed open porch, some basements).
• A wet location is exposed to weather, subject to saturation, or, in the UL wording, a place where water can drip, splash or flow on or against the fixture.
• Fixtures in wet locations are marked "Suitable for Wet Locations"; fixtures in damp locations are marked either "Suitable for Damp Locations" or "Suitable for Wet Locations". A dry location fixture carries neither.

Use this to read a box and to ask. Write in the brief: "Which of these fixtures need a damp or wet rating where we want them, and does the bathroom circuit have the ground-fault protection the code requires?" Ask the authority NFPA's consumer guidance adds that GFCIs (ground-fault circuit interrupters) are tested monthly, following the maker's instructions (NFPA Educational Messages, 2026).

4. Desks, screens and video calls

A desk has two tasks that want different light: paper, which wants light on it, and a screen, which makes its own light and suffers from reflections.

The desk lamp

VisionAware, a low-vision resource from the American Printing House for the Blind, gives a set of task-lamp tips (VisionAware, Lighting and Glare):

• Put the lamp close to the task (the inverse-square law again).
• Put it on the side opposite your writing hand, so your hand's shadow does not fall on the work: left side if you write with your right hand.
• Keep the shade below eye level, with the bulb recessed in the shade, so the bulb is not in your eyes.
• Use task light with room light, not instead of it, so the room is not dark when you look up.

Preference These are one organization's tips, without cited sources; they agree with the geometry in section 1. Try the lamp on each side and keep the one that leaves no shadow.

Screen glare

Reflected glare is a bright source seen in a shiny surface: a window or a lamp in your monitor. VisionAware suggests positioning the screen so the window or lamp is behind the screen, not reflecting off it; for paper it suggests working with your back to the window so light does not reflect off the task. The two can pull in different directions at one desk, so test. The Canadian Centre for Occupational Health and Safety gives three tests (CCOHS, Lighting Ergonomics: Survey and Solutions), which Survey and test your rooms introduced (glare tests):

• Mirror test. Lay a small mirror face up on the work surface, or look at the dark screen. If it shows a fixture or the window, that source causes reflected glare.
• Blocking test, reflected. Look at the task and block light from in front or above with a book. If details get easier to see, reflections are the problem.
• Blocking test, direct. From your seat, look at something distant at eye level and block the light from the fixtures. If it gets easier to see, the fixtures cause glare.

Run them at the time of day you work. A west window is a different source at 3 p.m. than at 9 a.m. Test it The fixes are the ones Layers, fixtures and glare named: turn the desk, close a blind for those hours, move the lamp, or shade the fixture.

Light for video calls

For a video call, your face is the task. The same geometry applies as at the mirror: light from in front and to the sides lights a face evenly, and a bright window behind you puts your face in shadow on camera. Test it Sit where you take calls, open the camera preview, and try the desk lamp aimed at a wall in front of you, the window to one side, and the blind closed behind you. Keep the setup the preview likes best.

Laundry and utility rooms

A laundry room's task is reading labels and finding stains. The Defense Department criteria give 200 lux at 3 ft above the floor. In California, for example, the 2025 code as Roseville summarizes it puts at least one laundry-room light on a vacancy or occupancy sensor (Switches, dimmers and evening light). A reading on the folding surface before and after a change works as it does in the kitchen.

5. See it: Tunde and Sam's kitchen, Noor's desk See it

• LRC, Lighting Rooms: Kitchen (archived copy of a page the Lighting Research Center no longer hosts): the kitchen plan with under-cabinet, sink and cove light; use the placement, not its 2000s lamp choices.
• CCOHS, Lighting Ergonomics: the glare tests in a government agency's words, written for workplaces and usable at home.
• H.E. Williams, Dry, Wet, and Damp Locations: the definitions and markings on one page, so you can read a fixture box.

6. Practice: a before and after on one work surface Practice

Minimum: one work surface, one reading before, one task light added without wiring (or noted for the brief), one reading after. Time: about 30 minutes. Materials: your meter or phone app, a lamp or a plug-in or battery under-cabinet light you have or can borrow, a small mirror, a book, and the tests sheet.

1. Pick the surface. The counter where you cut, the mirror where you shave or put on makeup, or the desk where you write.
2. Find your shadow. Stand or sit as you work, with the room's usual lights on. Note where your shadow falls.
3. Take the before reading. Phone or meter flat on the surface (at the mirror, held at your chin facing the mirror's light), average of three, after dark or at the hour you work. Write it with the spot and device.
4. Add the task light. In front of you and to the side, close to the surface, shade below eye level. At a desk, opposite your writing hand.
5. Take the after reading in the same spot with the same device, and note whether the shadow moved.
6. Run the glare test that fits. Mirror test at a desk; look in the mirror for shadows under brows and chin at a vanity.

7. Your rooms Your rooms

8. Check your work Check your work

Criteria

• The tests sheet has a before and an after reading for one work surface, same spot and device.
• The task light is in front of you or to the side, not behind, and your shadow is off the work.
• At a desk, the lamp is opposite your writing hand and the mirror test shows no fixture or window.
• Anything that needs wiring, or a damp or wet rating, is a row in the plan for the brief, written as a question.
• You read your readings as a comparison, not against a target as a pass mark.

Worked example

Tunde and Sam (fictional) meet the criteria for planning: the counters have a task layer on its own switch, the grid is labelled general light, and the downlight count, IC rating and dimmer are questions for the electrician. Their readings come after the work. Noor (fictional) meets them for her desk: the window is identified as the glare source, the lamp is on the correct side, and her before and after readings are recorded.

Common mistakes

• Adding ceiling light to fix a shadowed counter. A light behind you casts the same shadow, brighter.
• Lighting the mirror from above only. Light from the sides or bounced from the ceiling reaches under the chin.
• Putting a plug-in lamp beside a sink or tub. Keep lamps and cords away from water.
• Running the glare test in the morning for a desk used in the afternoon.
• Reading a pendant height off a chart. Hang a mock-up.

What is still unresolved

Whether a work surface is lit well for you is settled by your readings and your eyes. Where a fixture may go in a bathroom or near a sink, and the circuit protection it needs, is settled by the electrician and the inspector. How many downlights a kitchen needs is settled by the electrician's layout and the readings after the work.

9. Knowledge check and scenario

Checklist

• The tests sheet has a before and an after reading for one work surface (or I have no work room and went on to Living rooms, bedrooms and stairs).
• I know where my shadow falls at that surface, and the task light is in front of me or to the side.
• Anything that needs wiring or a damp or wet rating is a row in my plan for the brief.
• I ran the glare tests at my desk at the hour I work. (Go deeper; optional)
• I took counter readings along the counter and worked out the highest-to-lowest ratio. (Go deeper; optional)