The short answer
VELUX, FAKRO and Keylite all make opening roof windows for pitched roofs, and the differences that matter sit in the details: the size range, the opening types, the glazing choices, the flashing kits and the lead time on the day you order. Because the right window depends on your roof, our quote lines up several makers next to each other.
What the makers have in common
The three names above are among the best-known roof window makes in the UK, and each sells windows in a range of standard sizes with matching flashings for different roof coverings. Each also offers glazing, opening and finish options, and each backs its windows with its own warranty.
That overlap is why comparing them is worth the effort. A homeowner who sees one brand name on a neighbour's roof may assume it is the only choice, when another maker's window of a similar size could suit the roof equally well, sometimes with a shorter wait. The brand names are used here only as facts about products, and we are not tied to any one of them.
Our main roof windows page covers the types of window, and our guide to VELUX windows looks at that make in more detail.
The measures that separate one make from another
Five measures decide most comparisons. Sizes come first, because the window has to sit between the rafters, or take the place of an existing one without the roof being opened up. Opening type is second, and glazing third. Flashing kit is fourth, because it must match your tile or slate. The fifth measure is lead time, which varies between makers and between sizes.
| Item | VELUX | FAKRO | Keylite |
|---|---|---|---|
| Size range | Wide range, with a letter and digit size code | Own range, with its own codes | Own range, with its own codes |
| Opening types | Top-hung and centre-pivot, among others | Check the current catalogue at survey | Check the current catalogue at survey |
| Glazing | Choice of glass options by model | Choice of glass options by model | Choice of glass options by model |
| Flashing kits | Kits for each covering type | Kits for each covering type | Kits for each covering type |
| Lead time | Stated on the quote | Stated on the quote | Stated on the quote |
The table stays deliberately general, because ranges and prices change and the current catalogue is the only reliable source. We check it for each quote, and write the findings into the written comparison so the choice is in front of you.
Sizes and size codes
Every maker has its own size system. A VELUX size code like MK04 is read as a width letter followed by the digits that give the height. Another maker uses a different code for a window of the same real size, so a code from one catalogue cannot simply be typed into another.
For a replacement, the sizes already in your roof set the starting point. A window from a different maker can often be fitted into the same opening if the flashing and sides are adjusted, though a size that is close but not exact usually needs a little work to the surrounding roof. Our guide to VELUX window sizes explains the codes, and our answer on replacing an old VELUX window shows how that choice works in practice.
Opening types, glazing and flashing kits
Top-hung and centre-pivot windows are the two opening types most people meet, and they feel different in use. Our guide to top-hung and centre-pivot windows compares them. Some models in each range also open by electric motor, often with a rain sensor that closes the window, which is covered in our guide to electric opening rooflights.
Glazing options include different levels of insulation, noise reduction, solar control and a coating that helps the glass stay clean. Part L 2021 treats a roof window on an existing dwelling as a window, so the target is 1.4 W/m²K or else WER Band B, and each model's data from its maker shows how it measures up.
The flashing kit is the part people overlook. A kit is made for a roof covering, such as plain tiles, interlocking tiles or slate, and for how many windows sit side by side. The wrong kit lets in water, so we choose it from the roof, not from the brand. Our guide to VELUX flashing kits explains the choices.
Price, lead time and how we compare them for you
Price differences between makes shift from one size and spec to the next, so no maker is always lower. A fair comparison puts the same size, glazing and opening type from each maker next to each other, with the flashing kit and the fitting shown as separate lines. What moves the figure is explained in our answer on what a roof window costs to fit.
The quote states lead time as the typical range given by the maker. A window that arrives sooner can be the better choice where you want the work done by a particular date, even if another option suits the roof a little better on paper.
- Same size and glazing for each make
- Flashing kit shown on its own line
- Lead time stated for each option
Book a free survey and we will measure the roof, then set suitable windows from more than one maker out side by side in writing.
Related questions
Is a VELUX window better than a FAKRO or Keylite one?
No make is better for every roof. Each has strengths in particular sizes, glazing and opening types, and the right one depends on your opening and your roof covering.
Can I mix makes on one roof?
You can, though matching the windows on a roof slope gives a neater result, because frames, colours and sizes line up. We say so on the quote when it applies.
Will a different make fit the hole left by my old window?
Sometimes it fits directly, and sometimes the opening needs small adjustments. The survey checks the existing size against the other makers' ranges and the quote shows what is needed.
Do you only fit one brand?
We fit roof windows from more than one maker and list the options on the same sheet, so you can compare them before you decide.