Rooflights vs roof windows vs skylights: what’s the difference? Learn which suits your roof and explore GLRE’s UK-made range. Get expert advice today.
A rooflight, a roof window and a skylight all bring natural light through a roof, but the terms are not interchangeable. In short, “rooflight” is the broad industry term for any glazed unit set into a roof, a “roof window” is a specific unit fitted in line with a pitched roof slope, and “skylight” is a more general word often used to mean the same thing as a rooflight. To see the options for your project, explore GLRE’s range of rooflights and skylights. This guide explains each term and helps you choose the right product for a flat or pitched roof.
The main difference lies in how each unit is installed and how the terms are used in the UK building trade. The table below summarises the key distinctions.
| Feature | Rooflight | Roof window | Skylight |
| Common usage | Preferred trade and manufacturer term | Specific product type | General or consumer term |
| Typical roof | Flat or low-pitch roofs | Pitched roofs | Flat or pitched roofs |
| Installation | Sits proud of the roof, often on an upstand | Fitted in plane with the roof slope | Broadly the same as a rooflight |
| Governing standard | Product-specific | BS EN 14351-1 | No separate standard |
In everyday conversation, rooflight and skylight are often used to mean the same thing. Roof window has a more precise meaning, which we explain below.
A rooflight is a glazed unit built into a roof to bring in daylight. It is the broad term that professionals, including architects and manufacturers, use for almost any glazing set into a roof.
Rooflights are most commonly fitted to flat or low-pitch roofs, where they sit slightly proud of the roof surface, often on a kerb or upstand. They come in many forms, including flat glass rooflights, pyramid rooflights and circular rooflights.
A roof window is a specific type of glazed unit that is installed in the same plane as the surrounding roof, so it sits flush with the tiles or slates. It is designed for pitched roofs.
Roof windows are covered by the product standard BS EN 14351-1 and are typically installed at a minimum pitch of around 15 degrees. In practice, a roof window opens like a conventional window and is a common choice in loft conversions.
A skylight is a general term for a window in a roof that lets in natural light. It is used more often by homeowners than by trade professionals, and in the United States it is the standard word for what the UK calls a rooflight.
There is no strict technical difference between a skylight and a rooflight in the UK. The term you hear often depends on who you are speaking to rather than on the product itself.
Your roof pitch is usually the deciding factor.
Ventilation is another consideration. If you want airflow as well as light, an opening rooflight is available with manual or electric operation.
GLRE specialises in UK-made rooflights and skylights, precision-engineered by a team with over 50 years of experience in architectural glazing. Every product is backed by a 25-year quality guarantee.
We hold recognised industry accreditations, including ISO certification, CHAS Elite and Constructionline Platinum. You can review detailed specifications on our technical drawings page or read real projects in our case studies.
Still deciding?
Not sure which is right for your roof? Contact the GLRE team for expert, no-obligation advice.
