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Solatube alternatives: heliostat vs. sun tunnel
Looking for a Solatube alternative? All of these bring daylight into dark spaces - but in very different ways. A light tube pipes light down from the roof; a heliostat aims real sunlight wherever you want it. Here's how to choose.
The quick answer
- Choose a light tube / Solatube if you have a suitable roof above the room, want a passive fix, and don't need to aim or schedule the light.
- Choose a heliostat if the room has no usable roof access (e.g. lower floors), if you want to direct sun to a specific spot - indoors or outdoors - or if you want control, scheduling and winter performance.
Side by side
| Heliostat | Solatube / sun tunnel | |
|---|---|---|
| How it works | Tracks the sun and redirects sunlight onto your target | Passive shaft pipes roof light down |
| Installation | Outdoor mount; uses an existing window | Roof penetration + ceiling work |
| Aim / schedule | Yes - app-controlled, multiple spots | No - fixed |
| Lower-floor rooms | Works (no roof needed) | Hard or impossible |
| Outdoor use | Yes - terrace, garden | No |
| Low winter sun | Actively re-aims to catch it | Weak when sun is low |
| Moves with you | Retrofittable / removable | Permanent |
What each is best at
Solatube and sun tunnels
These are proven, low-maintenance and invisible once installed. For a top-floor bathroom, hallway or walk-in closet directly under the roof, a light tube is often the simplest answer. The trade-offs: it needs building work, it can't be redirected, and it delivers diffuse light only where the tube ends.
Heliostats
A heliostat is the flexible, active option. Because it sits outside and reflects through a window, it reaches rooms that no roof shaft can - including ground-floor and shaded rooms - and it can put sun on a desk at 9 a.m. and a reading chair at 4 p.m. It's also the only one of the three that works outdoors, reclaiming a shaded terrace or garden seat.
A note on cost
Light tubes are usually cheaper to buy but add installation labour and roof work. A premium home heliostat is a higher up-front device cost, but it's retrofittable, needs no structural work, and you can take it with you. The right choice depends less on price than on where you need the light and whether you want to control it.
Frequently asked questions
What's the real difference between a heliostat and a Solatube?
A Solatube (sun tunnel) pipes daylight straight down from the roof through a fixed tube - no aiming, no moving parts, best for a room directly under the roof. A heliostat is a motorised outdoor mirror that tracks the sun and redirects real daylight through an existing window to a spot you choose - it works on any floor and can be aimed, but needs power and a spot with real sun.
Which one works if I'm not on the top floor?
A heliostat. Sun tunnels need a short, direct run to the roof, so they don't suit flats with occupied floors above. A heliostat sends light through a window, so the floor doesn't matter.
Do either need construction?
A skylight or sun tunnel needs roof work - cutting and sealing the roof. A heliostat mounts outside and uses your existing window; nothing is built or cut indoors, and it's reversible if you move.
Is redirected sunlight from a heliostat safe? Does it concentrate?
No. The mirror is slightly convex and creates no focal point, so you get a broad area of light. Safety is not carried by that shape alone - no-glare zones are enforced in firmware, the mirror parks itself in a safe position, and the siting notes are part of the installation. Two of the three are in the device, the third is yours to follow.
Want to aim daylight, not dig through the roof?
The ohoya Heliostat redirects real sunlight to any spot - indoors or on the terrace - with app control and no building work. Reserve from €49, fully creditable and refundable.