Guide · Daylight without construction

Can You Redirect Sunlight Indoors Without Construction?

Most ways of adding daylight to a dark room involve building something: cutting a skylight, fitting a sun tunnel through the roof, or knocking through a wall. If you rent, live in a flat, or simply don't want the mess and cost, that can feel like a dead end. The short answer: yes - by redirecting the sun you already have, rather than building a new opening for it.

The idea: move the light, don't rebuild the room

Somewhere on most properties, the sun does reach - a balcony, a sunny exterior wall, a patch of garden, a roof terrace. A heliostat puts a motorised mirror in that sunny spot and reflects real daylight through an existing window into the shaded room. Nothing is cut, drilled through the roof, or built indoors. You're relocating sunlight, not renovating.

Because the mirror tracks the sun as it moves, the redirected daylight keeps landing on the same spot - a wall, a floor, a ceiling - for hours, instead of drifting away after a few minutes as a fixed mirror would.

What "no construction" actually means here

• No roof work. Unlike a skylight or sun tunnel, nothing penetrates the roof.
• Nothing built indoors. The light comes through a window you already have.
• Mounting is outside, where the sun is. Placed on a balcony, wall bracket, railing or garden stand - a normal fixing, not a building project.
• It's reversible. Renting? A mounted heliostat can be removed and taken with you, unlike a cut-in skylight.

This is why redirecting sunlight suits flats, rentals and rooms with occupied floors above them - exactly the places a sun tunnel can't serve. (For the full comparison, see Heliostat vs. Solatube vs. sun tunnels.)

How a home heliostat does it

A modern home heliostat like ohoya replaces old manual calibration with software:

• It calculates the sun's position locally from location, date and time, and keeps the reflected daylight on your chosen spot - no constant re-aiming by hand.
• You set it up once with your phone. Augmented reality lets you point the light and draw "no-go" zones. The device itself has no camera, ever - the app uses your phone's camera only for that one-time setup, and the images stay on your phone.
• The light arrives as a broad area. A slightly convex mirror creates no focal point. Glare is kept off eyes and neighbours by three measures: no-glare zones in firmware, a safe park position, and the siting notes you follow.
• It runs local-first. No account and no cloud required; everyday operation works without an internet connection (the initial AR setup needs internet once).

When redirecting sunlight is the right call

If all three are true, redirecting sunlight is very likely your most practical route to real daylight indoors:

• You can't or don't want to build - a rental, a flat, a listed building, or just no appetite for roof work.
• The dark room has a window, even one that faces the shade.
• There's real sun somewhere on the property for the mirror to catch - a few hours of direct sun on a balcony or wall is ideal.

And when you compare devices: prefer open smart-home compatibility over a closed app-only system - look for “Matter-ready”.

Frequently asked questions

Do I need to modify the room or the window?

No. The daylight enters through your existing window; nothing is built or cut indoors.

Where does the mirror go?

Outside, in a spot that gets direct sun - a balcony, an exterior wall, a railing or a garden stand - using a normal mount.

Is it safe to bounce sunlight into a room?

The mirror is slightly convex and creates no focal point, so the light arrives as a broad area of daylight. What keeps it out of eyes and off neighbours is not that shape on its own but three measures together - no-glare zones enforced in firmware, a safe park position, and the siting notes in the manual. Two are built in, the third one you follow when you choose the spot.

Can I take it with me if I move?

Yes - because it's mounted rather than built in, a heliostat can be removed and reinstalled elsewhere.