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Bigelow Interior Design

The Design Studio

The Room Ambience Planner

Work out exactly how much light your room needs, how to split it across the three layers every designed space uses, and which colour temperature to buy.

Lighting is the cheapest way to change a room

It is also the thing most homes get wrong. Not because the fixtures are bad, but because there is only one of them — and because nobody reads the numbers on the box.

01

One big light flattens a room.

A single ceiling fixture throws light from one direction, which erases texture and drops the corners into shadow. It is the reason a room can be bright and still feel unwelcoming. Three layers at lower individual output will always beat one bright source.

02

Lumens matter, watts do not.

Wattage tells you what a bulb costs to run, not how much light it gives. LEDs broke that old link entirely. Read the lumen figure on the box and ignore the watt equivalence, or you will keep buying by a number that no longer means anything.

03

Mixed Kelvins cheapen everything.

Warm and cool bulbs in the same sightline fight each other, and the eye reads the whole room as slightly wrong without being able to say why. Matching colour temperature costs nothing and is the fastest upgrade most homes can make.

The Design Studio

The Room Ambience Planner

One overhead light is why a room feels flat. Enter your space and get the full three-layer plan — lumens, fixture counts, and the right colour temperature for each.

Room type
AmbianceSoft and warm, with light pooled rather than flooded.

Enter your room size to see the full lighting blueprint.

Based on IES foot-candle standards. Fixture counts assume roughly 800 lm ambient, 600 lm task, and 300 lm accent per unit — check the lumen rating on the box, not the wattage.

Common lighting questions

How many lumens do I need per square foot?
Multiply your room’s square footage by its foot-candle target: about 15 for a living room, 12 for a bedroom, 35 for a kitchen, and 40 for a home office. A 220 square foot living room therefore needs roughly 3,300 lumens in total. Reduce that by around 15 percent for a cozy scheme or 40 percent for a deliberately moody one, and add roughly 12 percent for every foot of ceiling above the standard eight.
What are the three layers of light?
Ambient, task, and accent. Ambient is your overall foundation, usually overhead, and carries roughly 40 to 50 percent of the total. Task light covers the places you actually do things — worktops, desks, bedsides — and takes 25 to 45 percent depending on the room. Accent light picks out art, shelves, and architecture with the remaining 15 to 25 percent. A room lit by only one of the three always feels flat.
What Kelvin colour temperature is best for each room?
Use 2700K in living rooms and bedrooms for a warm, relaxed light. Kitchens work best at 3000K for general lighting with 4000K over work surfaces, and a home office wants 3500K to 4000K to help you stay alert. Lower numbers are warmer and yellower, higher numbers are cooler and bluer. Below 2700K reads candlelit and dramatic; above 5000K reads clinical in a home.
Can you mix different Kelvin bulbs in the same room?
No — not within the same sightline. Mixing colour temperatures is the most common lighting mistake in homes, and it makes an otherwise expensive room look cheap, because one cool bulb turns every warm bulb around it visibly yellow. The single exception is dedicated task lighting, such as a 4000K strip under kitchen cabinets, where the cooler light genuinely helps you see. Everything else in the room should match.
How many light fixtures does a room need?
Divide each layer’s lumen target by the output of a typical fixture: around 800 lumens for an ambient downlight, 600 for a task lamp, and 300 for an accent fitting. Most rooms end up with three to six ambient sources, two to four task lights, and two or three accent pieces. More small sources always beat one bright ceiling light, because pools of light are what create depth.
Why does my room feel flat even with bright lights?
Because it has one layer instead of three. A single overhead fixture flattens everything it touches and pushes the corners into shadow, which reads as harsh and unfinished no matter how many lumens it produces. Add task lighting at the places you sit and work, plus a little accent light on a wall or shelf, and put all of it on dimmers. The room will feel completely different at the same total brightness.

Measuring for curtains or art next? Visit the Scale & Placement Guide.