A rooflight (often used interchangeably with "skylight") is a glazed unit installed in a roof to bring natural light into the space below. In the UK, they are a staple of modern extensions, providing up to three times more light than a standard vertical window of the same size.
By 2026, rooflight technology has focused heavily on minimalist design (frameless looks) and smart integration (automated venting).
The "best" type depends entirely on your roof pitch and the architectural look you want.
- Flat Rooflights: Fixed or opening glass panes designed for flat roof extensions. The most modern versions are "frameless" from the inside, giving a seamless view of the sky.
- Roof Lanterns: A 3D "pitched" structure that sits proud of a flat roof. They are popular for "zoning" open-plan kitchens or dining areas, adding both height and architectural drama.
- Pitched Roof Windows (e.g., Velux): Designed to sit flush within a sloped roof (15 degree to 90 degree). These are the standard for loft conversions.
- Walk-On Rooflights: Feature extra-thick toughened glass designed to be part of a roof terrace or floor, allowing light into a basement or room below without losing outdoor floor space.
- U-Value Measures heat loss. Most quality units now aim for 1.2 Wm2k to comply with 2026 energy standards.
- Solar Control A coating that reflects infrared heat. Crucial for south-facing roofs to prevent the "greenhouse effect" in summer.
- Smart Sensors Many opening models now feature built-in rain sensors that automatically close the window at the first drop of rain.
- Self-Cleaning Glass Uses UV rays to break down organic dirt and rainwater to wash it away, reducing maintenance on hard-to-reach roofs.
For most UK residential projects, rooflights fall under Permitted Development, meaning you don't need full planning permission if:
- They do not protrude more than 150mm above the roof plane.
- They are not higher than the highest part of the existing roof.
- Any side-facing rooflights are obscure-glazed for privacy.