The differences at a glance
| Decision | REHAU | Deceuninck |
|---|---|---|
| Standard casement shortlist | Identify the quoted TOTAL70 configuration. | Identify 2500 chamfered or 2800 sculptured, as applicable. |
| Flush shortlist | Ask whether the proposal is Rio Flush Fit. | Identify the exact flush system and frame detail. |
| Appearance | Compare the full frame, sash and joint sample. | Compare the full frame, sash and joint sample. |
| Finished quotation | Name the fabricator, glass and hardware. | Name the fabricator, glass and hardware. |
Which products are actually being compared?
REHAU lists TOTAL70 casement and Rio Flush Fit options. Deceuninck separates its 2500 chamfered, 2800 sculptured and flush options. Those names help you establish a fair starting point. If one quote is for an overlapping sash and another for a flush finish, part of the price difference may be the design rather than the brand. Ask both suppliers to mark the system and sash style on the elevation drawing.
What should you look at in person?
Start with the corners, meeting lines, opening lights and visible glass. Take a frame sample to the property and inspect it beside the brickwork in daylight. A colour name is not enough to establish that two finishes match. If doors will be fitted at the same time, ask to see the window and door samples together. Confirm the room-side finish as well as the external colour.
When is paying more worthwhile?
Treat a higher quote as a list of differences to investigate. Does it include a preferred finish, a better arrangement of openings, the glass you need or a clearly scoped installation? Request the complete-window thermal information for the quoted assembly. A profile brochure alone cannot establish the performance of the finished window. Ask who will handle adjustment, glass faults and hardware problems after fitting.
What this means for a real brief
Two quotes describe anthracite windows, but the REHAU proposal uses a standard casement and the Deceuninck proposal is flush. Request a matching flush alternative before deciding that the second brand is more expensive. Then compare glass, finish, fabrication and the installed scope.
Turn the comparison into a shortlist
Mark each proposal as confirmed, needs clarification or does not meet the brief. Resolve a failed essential requirement before scoring cosmetic preferences. If both options meet the essentials, compare the extra cost of the details you will notice every day.
- Write down the three essentials for your project: appearance, everyday operation and any required performance.
- Request a dimensioned drawing with opening direction, handles and the exact model.
- Keep glass, finish, survey and fitting scope consistent between quotations.
- Ask for written delivery, warranty and aftercare responsibilities.
- Keep allowances separate from confirmed costs; compare VAT on the same basis.
Manufacturer references
Checked 12 October 2026. Our buying scenarios and decision guidance are editorial interpretation. Manufacturer names identify comparison options and do not imply an approved dealership or confirmed supply relationship.