Understand what is included before comparing the final number. Appearance and price per square metre rarely tell the whole story.
Start by making the two offers comparable
Two windows can have similar colours and dimensions while representing different specifications. One quotation may include a different opening layout, glazing build-up or hardware package. Transport, installation, surrounding finishing or screens may be treated differently too.
Ask each supplier to describe the same set of items. This is not about automatically preferring the most expensive offer or rejecting the least expensive. It is about understanding which product and amount of work each price represents, and whether it suits your project.
The profile must suit the opening
The frame and moving sash need to be selected for the dimensions, geometry, glazing weight and project requirements. Those factors affect the system that can be proposed. A profile that works for one opening should not automatically be copied to a larger or differently configured opening.
Visible width, wall thickness and the amount of aluminum are not independent proofs of suitability. There is no universal height at which every window needs the same heavier profile. Ask why the proposed system is appropriate and how its configuration will be confirmed.
Build your quotation comparison
Use this list during your project discussion. Your choices stay on this page.
Look inside the glazing description
“Double glazed” leaves several questions unanswered. Ask about the pane build-up, glass type, coatings where specified, spacer and edge construction. Different choices can affect appearance, manufacture and cost even when the finished glass looks similar.
The catalogue’s 10, 14, 16 and 20 mm spacer options are choices within compatible assemblies. Wider does not automatically mean better. The useful comparison is between complete glazing proposals responding to the same requirements for the opening, room and exposure.
Hardware and its supporting detail matter
A sliding leaf places demands on rollers, guides, locking and the sections that carry them. A hinged sash needs compatible hinges and locking components. Ask what is included and how it relates to the selected panel and glazing.
Try the representative sample rather than judging from a handle photograph. Move the leaf, operate the lock and ask about service parts. Across several openings, differences in hardware and accessories can contribute to a difference in price and in everyday use.
Remember seals, screens and finish
Seals and brushes may be less visible than a frame face, but they are part of the complete opening. Ask about their intended arrangement and how they meet at the moving joints. Appearance alone will not explain these details.
If screens are included, compare their construction, operation and closing arrangement. Confirm the finish using a sample and identify which surfaces receive it. A particular architectural expression or finish may involve a different specification. Record the actual choice rather than an imprecise description such as “premium finish”.
Read the work after fabrication
Check measurement, delivery, fixing, alignment, perimeter sealing, adjustment and the agreed finishing scope. Ask what site preparation is required and what is excluded. Installation is part of what you are purchasing, not a detail to clarify only when the frames arrive.
Compare the written programme, service contact and applicable warranty documentation alongside the product specification. Make a list of unanswered questions and resolve them before finalising the order. A clear, equivalent scope makes the price comparison useful; a universal claim about the cheapest or best window does not.
Questions to leave with.
- Both offers identify the product clearly.
- Options and exclusions are written down.
- Installation scope is equivalent.
- Unanswered questions have a named contact.
