Plan your room
Prefer the full contact form? Open it with this plan filled in.
Estimate only. This is a starting layout to help you plan, not a final design. The real layout depends on a site visit: ceiling joists, ducts and pipes, insulation, the fixtures you choose (their lumens, beam spread and ratings), and California electrical code. We’ll check all of that with you, and estimates are free.
How the planner works
- 1A target for the room
Each room type starts with a target in lumens per square foot, taken from the published foot-candle guidance for homes (table below). One foot-candle is one lumen per square foot (Ohio University). Most home lighting guides use these numbers this way: as the amount of light the ceiling lights should put out for each square foot of floor.
- 2How many lights
Lights = floor area × target ÷ lumens per light, rounded up. For a 14 × 12 ft kitchen with under-cabinet lights: 168 × 30 ÷ 900 = 5.6, so 6 lights.
- 3A spacing check
The lights go in an even grid with the outside lights half a space from the walls. The planner only adds lights if the grid would be wider than the room’s max spacing (about 1 to 1.25 times the distance from the ceiling to the counter, and never more than 8 ft). If it does add lights, it says so and suggests smaller or lower-lumen lights.
- 4A light-level check
The planner also estimates the light that reaches counter height, using the coefficient of utilization from a typical 6-inch wafer light spec sheet and a 0.9 light loss factor (Ohio University). This is shown as a check only. It comes out lower than the target because some light lands on the walls, which is why counters, mirrors and workbenches get their own task lights.
- 5Task lights, listed separately
Under-cabinet lights, vanity lights, island pendants and workbench lights are suggested on their own and are not counted in the ceiling lights. Watts are rough; shop by lumens (ENERGY STAR).
Targets we start from
| Room | Published guidance (foot-candles) | Planner starts at (lumens per sq ft) | Max spacing | Source |
|---|---|---|---|---|
| Kitchen | 30–40 | 30 with under-cabinet lights, 40 without | 1.0 × | Penn State |
| Living room | 10–20 | 15 | 1.25 × | Penn State |
| Bedroom | 10–20 | 15 | 1.25 × | Penn State |
| Dining room | 30–40 | 20 | 1.25 × | Penn State |
| Home office | 20–50 | 30 | 1.0 × | Penn State |
| Bathroom | 20–50 | 30 | 1.0 × | Penn State |
| Laundry room | 30–50 | 40 | 1.0 × | IES table |
| Walk-in closet | about 28 (300 lux) | 30 | 1.0 × | Journal of Extension |
| Hallway | 5–20 | 8 | 1.25 × | Penn State |
| Garage / shop | 30 general, up to 100 at a workbench | 40 | 1.0 × | Penn State |
Published ranges differ a little from source to source, so we start inside the range and let you adjust. The walk-in closet value is the Illuminating Engineering Society figure for ages 25–65 as reported by the Journal of Extension; treat it as a starting point. The newest IES home lighting practice (IES RP-11) sets levels by age, and they roughly double for people over 65, so try a higher target if that applies.
California notes, in plain English
- Dimmers in living spacesLiving rooms, dining rooms, kitchens and bedrooms need a wall dimmer for the general lights (California Energy Commission).
- Auto shut-off in some roomsBathrooms, garages, laundry rooms, utility rooms and walk-in closets need at least one light on an automatic shut-off, such as a vacancy sensor.
- JA8-rated lightsNew lights generally have to be certified and marked to the state’s JA8 standard, with a few exceptions.
- Recessed lights: airtight, no screw baseNew recessed downlights can’t have a screw-in bulb socket, and they must be labeled airtight and sealed to the ceiling. Under-cabinet lights go on their own switch.
- Insulation, showers and closetsWhere insulation will touch a recessed light, it needs to be rated for that (IC-rated). Lights over a shower or tub must be rated for damp or wet spots, and closet lights have to stay a set distance from shelves and stored items. We check all of this on site.
These apply to new homes, additions and lighting changes under the 2025 California Energy Code (permits from January 1, 2026). Code details change, so this is a plain summary, not legal advice. See also the UC Davis residential lighting guide.
Have a floor plan or room scan?
Great, send it along. Many newer phones can measure a room and make a simple floor plan with a free scanning app (magicplan and Polycam are two examples; we don’t endorse any one app). A floor plan, a room scan, or even a quick sketch with measurements helps us give you a better estimate.
How to send it: mention it in your request on our contact page and we’ll reply so you can send the file, or text it to (530) 401-7419. You can also email it to walter@ieselectricalservices.com.
How IES helps
- We look before we cutWe check the ceiling framing, insulation and what’s already there, then adjust the layout so it looks right and works.
- Fixtures that fit your spaceWe help you pick lights by lumens, color and beam spread, and match dimmable lights with the right dimmers.
- Permits and code handledWe take care of the permit and inspection when one is needed.
- Free estimatesNo pressure. Call (530) 401-7419, answered 24/7, or send your plan below.
Learn more about our lighting and LED work and smart lighting.
Common questions
How many recessed lights do I need?
Multiply the floor area by a target for the room in lumens per square foot, then divide by the lumens of one light and round up. A 14 by 12 foot kitchen at 30 lumens per square foot with 900-lumen lights works out to 6. The planner starts from published guidance for each room and then checks that the lights aren’t spaced too far apart.
How far apart should recessed lights be?
A common rule of thumb is about half the ceiling height. Fixture spec sheets often allow a little more: a typical 6-inch wafer light spec sheet lists about 1.1 times the distance from the ceiling down to the counter. The planner uses 1.0 times that distance in kitchens, baths and work rooms, 1.25 times in living rooms and bedrooms, and never more than 8 feet. The outside lights sit about half a space from the walls.
What’s a foot-candle?
A foot-candle is one lumen of light landing on one square foot. Lighting guidance lists rooms in foot-candles: hallways need less light, kitchens and work areas need more. The planner shows a rough foot-candle estimate at counter height as a check.
Do under-cabinet lights change the count?
Yes. Under-cabinet lights put light right on the counters, so the planner starts a kitchen at 30 lumens per square foot with them and 40 without them. In California they also go on their own switch.
Is this layout ready to install?
No, it’s an estimate to help you plan. The final layout depends on a site visit: where the joists, ducts and pipes are, insulation, the fixtures you pick, and California code. We’ll go over all of that with you, and estimates are free.
Should I put my lights on a dimmer?
In California, living rooms, dining rooms, kitchens and bedrooms need a wall dimmer for the general lights, and it also lets one layout work for both bright tasks and a relaxed evening. LED lights need dimmable fixtures and a dimmer made for LEDs. We’ll help you match them.
Send your plan for a free estimate
Free estimates, no pressure. Tell us a little about the job and we’ll get back to you. Or call (530) 401-7419, answered 24/7.
Sources
- Penn State EGEE 102: How Much Lighting is Needed (recommended residential light levels, based on Illuminating Engineering Society guidance) courses.ems.psu.edu
- Illuminating Engineering Society: ANSI/IES RP-11-26, Lighting for Interior and Exterior Residential Environments store.ies.org
- Journal of Extension: Measuring Light with Useful Tools (Illuminating Engineering Society light levels by room and age group) doi.org
- How to Choose Lighting Based on IES Standards (residential foot-candle table, including laundry rooms) www.electricalmarketplace.com
- Ohio University ART 2640: Lumen Method Calculation (1 foot-candle = 1 lumen per square foot; coefficient of utilization) people.ohio.edu
- California Energy Commission: 2025 Residential Dwelling Units Lighting FAQs www.energy.ca.gov
- UC Davis California Lighting Technology Center: Residential Lighting Guide for the California Energy Standards cltc.ucdavis.edu
- ENERGY STAR: Learn About Brightness (lumens) www.energystar.gov
Light levels and rules of thumb checked against the sources above in November 2026. Sources are listed for reference only; we don’t sell or endorse any brand.