The brightest light you can put in a dark flat is one that lights the whole room from the ceiling, rated in tens of thousands of lumens. A normal bulb gives about 800 lumens. A SAD lamp gives about 1,000, aimed at your face from 10-40 cm. Sunday Light, the artificial skylight we make in London, gives 34,500 lumens from the ceiling and follows the colour of the sun through the day.
Most dark flats already have plenty of lamps. What they lack is a large, bright source overhead, which is what a window full of sky provides.
Why more lamps don't make a dark flat feel brighter
Light from a lamp falls off with the square of the distance. Sit twice as far from it and you get a quarter of the light, so a lamp brightens its own corner and not much else. Add three more and you get four bright corners.
Most homes sit at 100-300 lux. A well-lit office is about 500. Outdoors is 50 to 100 times brighter than a typical room, and that light arrives from the whole sky at once, from above. A flat that faces a wall, sits below street level or only gets north light never sees much of that sky, so it spends the day at lamp levels.
Making a room feel like daylight takes two things a lamp can't give: a lot of light, and light that comes from a large area overhead rather than a point at eye level. How many lumens a room needs works through the numbers for different room sizes.
Your options, from the cheapest
| Option | Light output | What it lights |
|---|---|---|
| Brighter bulbs in your existing fittings | About 800-2,500 lumens per bulb | The area around each fitting |
| SAD lamp | About 1,000 lumens; 10,000 lux only at 10-40 cm | Your face, for a 20-30 minute session |
| Sky panel (Philips Skylight, Nanoleaf, Govee) | 1,400-7,000 lumens | Like a bright ceiling light, with the look of a sky |
| Brighter floor lamp | Up to 60,000 lumens (maker's figure) | The room, from a 6 ft 3 in pole lamp |
| Sunday Light | 34,500 lumens | The whole room, from the ceiling, as an artificial skylight |
Brighter bulbs are the right first step and cost very little. Pick 4000-5000K for daytime rooms and a CRI of 90 or more so skin and wood don't look grey. They won't change how the room feels at 3pm in December, but they stop it feeling dingy.
A SAD lamp does what it says for seasonal affective disorder: 10,000 lux for 20-30 minutes each morning. It treats one person sitting still in front of it. The room around you stays as dark as it was.
Sky panels look like a patch of sky and run a daylight schedule. Their output sits between 1,400 lumens (one Nanoleaf Skylight panel) and 7,000 lumens (Govee's Sky Ceiling Light), which is a good ceiling light, not daylight. Brighter makes the brightest lamp we know of, $1,199 in October 2026, dimmable from 2,500 to 60,000 lumens from a pole that stands in the room.
What 34,500 lumens from the ceiling does to a dark room
The LED sits at the bottom of Sunday's arm and shines up at a sheet 120 cm across. The sheet scatters the bluer light and reflects the warmer light. It's called Rayleigh scattering, the same thing that makes the sky blue. You look up and see a sky glow with a warm centre, and the room gets soft, indirect light rather than a glare point.
Sitting under it you get 5,000 lux and more, reaching 10,000 lux at 60 cm from the sheet, and because the source is overhead and large, the light reaches you wherever you sit. Professor Russell Foster, who directs the Sleep and Circadian Neuroscience Institute at Oxford and advises us, put it this way: "Critically, you do not have to sit next to the device to get the levels of light that will deliver physiological benefits."
Set a schedule once in the app and it follows the sun: cool 6000K daylight in the morning, then warmer and dimmer through the afternoon, down to 2650K. We recommend having it off by around 6pm. The CRI is 97+, so colours look the way they do outdoors. Water flows through the arm to cool the LED, which is what lets it run at this brightness all day. At full brightness it costs about 10p an hour to run.
Will it fit in a flat?
Sunday hangs like a chandelier from a ceiling rose. Any qualified electrician can fit it in 1-2 hours, and nothing is recessed, so there's no cutting into the ceiling and a solid concrete ceiling is no obstacle. If the room has no ceiling light point, it can be powered by a cable run to a wall socket. More on that in artificial skylights that don't need a hole in the ceiling.
You need a ceiling of 240 cm or more. For ceilings between 240 and 280 cm there's a reduced-height mount that holds the disc 11 cm below the ceiling, and below about 260 cm it's best hung over a table or a sofa rather than a walkway. In London we install it for £450, and you can see one in person by appointment.
Sunday Light, our indoor sunlight fixture, is £5,900 in the UK, $6,900 in the US and €6,900 in Europe, with free worldwide delivery. It ships within 5 working days and comes with a 3-year comprehensive warranty covering all components. The full specification is on the sunlight ceiling light page. For a flat that faces north, how to light a north-facing room covers colour temperature and the winter months in more detail.
