The short answer
Yes. Other makers build roof windows to comparable sizes, and a simpler specification within any make, such as a fixed window where nobody needs to open it, also lowers the price. A cheaper window only saves money if it fits the opening already in your roof and meets the 1.4 W/m²K limit that applies to a new or replacement roof window (or Window Energy Rating band B). We can quote another make beside a VELUX for the same opening so the comparison sits on paper.
- Free survey, fixed written quote
- 10-year workmanship guarantee
What actually differs between makes

Sizes are another point. VELUX uses size codes such as MK04, with letters for the width and digits for the height, and other makers have their own systems. We convert everything into millimetres on the quote. That lets you test any maker's catalogue size against the gap in your roof, with the rafter spacing from the loft alongside.
| Point | Why it matters at the roof |
|---|---|
| Size against the existing opening | A near miss can mean trimming rafters or filling gaps |
| Glazing specification | Decides whether the window meets the energy limit |
| Opening style | Centre-pivot and top-hung suit different positions in the slope |
| Flashing kit | Must match the window and the covering of your roof |
| Blinds and motors | Often tied to one make, so check before choosing |
When the cheaper window costs more
The cheapest window on a list is not always the cheapest job. A unit has to be fitted, lined inside, flashed and finished, and each of those steps depends on how well it matches what is already there. If you are replacing an old VELUX and the new unit is a few centimetres different in width, the opening may need carpentry and fresh plasterboard lining. A flashing kit that was ordered separately, or that was left out of the first figure, brings the total back up.
A like-for-like swap into the existing opening avoids the extra carpentry and lining. What can be reused and what is replaced when an old unit comes out is covered in the guide to swapping an old VELUX window. Where a window is new to the roof, the opening is cut to suit whichever make you choose, so a size that is a catalogue standard keeps the carpentry simple. In a loft bedroom with a plastered slope, a window that matches the rafter spacing leaves the surrounding lining alone, and in an unfinished loft the choice of make hardly touches the structure at all. Tell us at the start if the ceiling has been decorated recently, since that affects how much making good the job needs.
Lowering the price within any make
Several choices move the figure whichever name is on the frame. A fixed window costs less than one that opens, and suits a stairwell or a spot beyond arm's reach. A standard catalogue size avoids a special order. Two windows grouped in one visit share access, scaffolding or ladders, and plain white finishes cost less than specials. A window over a bathroom or a kitchen sink may need glass suited to damp or to knocks, so it is wise to settle the room before the make.
Skipping blinds and motors at first keeps the opening cost down, though the wiring is easier to plan before the ceiling is closed. Our guides on VELUX window cost and roof window cost list what drives the price, and the answer on how much it takes to fit a VELUX window covers the labour side.
What moves the price of a roof window
- Opening or fixedA sash that opens needs hardware and a handle
- Size and whether it is a catalogue size
- Glazing specification and safety glass for bathrooms
- Roof covering and flashing kit
- Access to the roof
Setting two quotes side by side
Ask each firm to write down the make and model code, the size in millimetres, the glazing and its energy performance, the flashing kit, the internal lining and finishing, and how the Building Control notification is handled. Quotes that leave a line blank are not yet comparable. Ask too about waste removal, making good the plaster and decoration, and what is included if the opening turns out to differ from the drawing.
Our quote sets out each of those lines; it follows a free survey, the figure is fixed and in writing, and the workmanship is guaranteed for 10 years in writing. For a like-for-like comparison, book a survey and tell us which makes you want priced, or read about VELUX windows and common problems first.
