Project planning
How to Compare Window and Door Quotations Like for Like
Two totals only make a useful comparison when they describe the same work. A lower quotation might use a different opening layout, omit finishing work or leave a glazing choice undecided. Put the proposed product and the installation scope on the same page before comparing prices.
Give every opening a reference
Use a simple schedule: opening one, opening two and so on, with a room label and a drawing. Include which parts are fixed, which open, the hinge side and the direction of movement. Confirm whether a drawing is viewed from inside or outside; that small detail can change how a layout is read.
Treat your early measurements as planning information, not manufacturing instructions. Identify which dimensions have been professionally checked and who is responsible for the final survey. A consistent reference system makes later changes much easier to track.
Compare the complete product description
Record the frame finish, glass specification, handles, locks, vents and any other selected components. If a quotation uses a product range name, ask which configuration within that range it includes. The same family name can cover more than one arrangement.
For performance figures, check what they describe. A glass-only number is not automatically a complete-window figure. Keep the supporting product information beside the quotation so that a promising headline does not replace the actual specification.
Make installation and finishing explicit
Ask what happens before, during and after fitting. Does the scope include removing the existing units, dealing with waste, protecting the room and making good the surrounding surfaces? Which finishes are included, and which are to be completed by somebody else?
Write exclusions down as carefully as inclusions. If one proposal includes finishing work and another does not, place that difference beside the totals rather than hoping it will be minor. Where building requirements or permissions apply, clarify responsibility with the appropriate professional; do not assume a generic quotation answers them.
Record the assumptions behind the price
A proposal may rely on access being available, existing surfaces being sound or other work being completed first. Ask which assumptions have been checked and which remain provisional. Keep a clear distinction between an agreed item, an allowance and an option.
Do the same with timing. Record the proposed sequence and what could affect it without turning an estimate into a promise that was never made. If you choose a different finish or arrangement, request a revised written specification rather than relying on a conversation about the change.
Keep one current version
Save the selected drawings, specification, quotation and product information together. Mark superseded documents so they cannot be mistaken for the latest agreement. A short change log can be enough: what changed, when it changed and which document now applies.
A useful comparison is not a contest to collect the longest specification. It is a way to make sure that the design you are discussing, the work being priced and the product eventually supplied are all describing the same project.
Explore the subject: Glazing guide.
