If you’re looking to add natural light to your home, you may be deciding between a sun tunnel and a skylight (also called a roof window or rooflight). Both options brighten dark areas, but they work differently and suit different rooms. This guide compares cost, installation, energy efficiency, maintenance and long-term performance to help you choose the best option for your home.
Quick Summary
- Sun tunnels are ideal for dark internal rooms, hallways, stairwells and bathrooms.
- Skylights suit rooms where you want a view or ventilation, such as loft bedrooms or kitchens.
- Sun tunnels cost less, install faster, and prevent heat loss better than skylights.
- Skylights provide full daylight and sky views, but need structural roof alterations.
What Is a Sun Tunnel?
A sun tunnel captures sunlight on the roof and channels it down a reflective tube, delivering diffused natural daylight into interior rooms. It’s low-impact, fast to install and energy-efficient.
Best for:
✔ Internal rooms with no external walls
✔ Hallways and windowless bathrooms
✔ Areas where a skylight won’t fit
What Is a Skylight?
A skylight (roof window) is a glazed window fitted directly into the roof structure. It provides full daylight, ventilation and, in some cases, roof access.
Best for:
✔ Loft conversions
✔ Attic bedrooms
✔ Kitchens and living areas
✔ Rooms where you want a view
Sun Tunnel vs Skylight: Cost Comparison (UK 2025/2026)
| Feature | Sun Tunnel | Skylight / Roof Window |
|---|---|---|
| Typical installation cost | £600 – £1,200 | £1,500 – £3,500+ |
| Premium system cost | £1,200 – £2,800 | £2,500 – £6,000+ |
| Labour time | 2–4 hours | 1–2 days |
Sun tunnels are almost always cheaper to supply and install.
Installation Comparison
| Feature | Sun Tunnel | Skylight |
|---|---|---|
| Roof structure changes | Minimal | Yes (rafters altered) |
| Planning permission | Rarely needed | Sometimes required |
| Scaffolding | Often no | Often yes |
| Loft disruption | Low | Moderate to high |
Key point: Sun tunnels cause far less disruption and usually do not require structural changes.
Light Quality & Performance
| Feature | Sun Tunnel | Skylight |
|---|---|---|
| Light type | Diffused natural daylight | Direct daylight & sky view |
| Energy usage | Zero during the day | Zero during the day |
| Heat gain / loss | Very low | Moderate |
Sun tunnels produce steady, even light ideal for bathrooms, stairs and landings.
Skylights provide strong directional light and outdoor views, especially beneficial for loft conversions.
Ventilation & Airflow
- Skylights open — ideal for ventilation, moisture control and fresh air.
- Sun tunnels do not open — they purely deliver light, not airflow.
For humid rooms like kitchens or shower rooms, some homeowners install both: a sun tunnel plus a vented skylight.
Energy Efficiency
- Sun tunnels prevent heat loss and reduce daytime electricity usage.
- Skylights can lose heat in winter and gain heat in summer, although modern glazing improves performance.
Winner: Sun tunnels for energy savings.
Maintenance
| Feature | Sun Tunnel | Skylight |
|---|---|---|
| Cleaning | Low | Needs regular internal/external cleaning |
| Seal checks | Every 2–3 years | Every 1–2 years |
| Condensation risk | Low with insulation | Medium in bathrooms/kitchens |
Skylights require more upkeep due to glazing and moving parts.
Use Cases: Which Should You Choose?
Choose a Sun Tunnel if:
- The room has no direct roof access
- You want quick, clean installation
- You are trying to eliminate artificial lighting in daytime
- You want diffused, soft daylight
Choose a Skylight if:
- The room needs ventilation
- You want to see outside or create a focal point
- You are renovating a loft or attic room
Can You Install Both?
Yes — and many UK homeowners do.
Example combinations:
- A sun tunnel on the landing + skylight in the loft bedroom
- A sun tunnel in an internal bathroom + skylight in the ensuite
- Multiple sun tunnels along long corridors + single large skylight in the centre
This creates balanced light throughout the house.
Typical UK Brands Compared
| Brand | Best Product Type | Notes |
|---|---|---|
| Velux | Skylights & sun tunnels | Most popular UK choice |
| Solatube | Sun tunnels | Best daylight performance |
| Fakro | Both options | Good value |
| LiteLite | Sun tunnels | Affordable solutions |
Get Free Quotes
Tell us about your home and receive up to four free quotes for both sun tunnels and skylights. Get advice from vetted UK installers who work with Velux, Solatube, Fakro and more.
Compare options, save money, and choose the best daylight solution for your space.
Frequently Asked Questions
Which lasts longer, a sun tunnel or a skylight?
Both systems last many years, but sun tunnels have fewer moving parts and typically require less maintenance.
Do sun tunnels work in winter?
Yes — reflective tubes capture and deliver light even in overcast conditions.
Are skylights better for upstairs rooms?
Often yes, especially in bedrooms and loft spaces where you want views and airflow.
Will a sun tunnel add value to my home?
Yes — it improves natural lighting and reduces energy usage.
Can sun tunnels leak?
Leaks are rare when installed professionally. Most issues come from damaged flashing or roof seals.