A window quotation should give you enough information to understand what you are actually buying. If something about the product, installation, glazing, guarantees or final specification is unclear, it is reasonable to ask.
This guide covers useful questions to ask before choosing replacement windows, helping you compare quotations properly and make sure important details have not been overlooked.
Most homeowners do not buy replacement windows very often.
That makes it easy to focus on the obvious things such as style, colour and price while overlooking details that become important later.
A good quotation should help you understand what you are buying, but it is still useful to know which questions are worth asking.
You do not need to become a glazing specialist.
You just need enough information to compare options properly and avoid agreeing to a specification you do not fully understand.
If you are still at the early research stage, start with our Choosing the Right Windows guide.
This sounds obvious, but quotations are not always as clear as they should be.
Ask for the actual window system or product range being quoted.
That helps you understand:
It also makes it easier to compare one quotation with another.
A quote that simply says "white uPVC windows" does not tell you very much.
Make sure the quotation reflects the actual style you want.
That could include:
If you are still comparing them, use the Window Styles guide.
Do not assume the opening configuration shown on a brochure or sample is what has been quoted for your home.
Ask to see the actual arrangement.
This matters because opening sections affect:
A small change to a mullion or opening sash can noticeably alter both the inside and outside of the window.
Fixed panes can be useful where an opening is not needed.
They can provide a cleaner appearance and reduce the amount of visible hardware.
But they need to be planned properly.
Ask which panes are fixed and which open so there are no surprises after installation.
Make sure you know whether the quotation is based on uPVC, aluminium, timber alternative or another system.
The material influences:
Our Window Materials guide compares the main options.
Do not settle for a vague answer such as "standard double glazing".
Ask what has actually been specified.
Useful questions include:
The Glass & Glazing guide explains the main options.
If energy efficiency is important, ask for the performance of the complete window rather than the glass alone.
A whole-window U-value gives a more useful indication of thermal performance because it includes the frame as well as the glazing.
The Window Energy Efficiency guide explains U-values and Window Energy Ratings in more detail.
Some products are also supplied with a Window Energy Rating.
That can be useful for comparison, but it should not be treated as the only performance figure that matters.
Ask how the rating relates to the exact product being quoted.
Ask what you are actually getting, not what is available as an upgrade.
Useful points include:
Our Window Security guide explains why the complete system matters more than one lock.
Optional upgrades can be useful.
They can also add cost without solving a real problem.
Ask what the upgrade changes and whether it is recommended for your particular property.
A ground-floor accessible window may justify more attention than a difficult-to-reach upper-floor opening.
Make sure the written quotation matches the colour you have chosen.
Ask whether the finish is:
If the windows are a different colour internally and externally, make sure both are recorded.
Our Window Colours & Finishes guide covers the design side of that decision.
You should if possible.
Screens are not reliable enough for a long-term exterior choice.
Ask to see the actual finish and, ideally, hold it against the brick, stone or render where the windows will be installed.
This is worth asking if only part of the house is being replaced.
Will the new frame colour, proportions and glazing lines work with the windows that are staying?
If the answer is no, decide whether the contrast is intentional.
Do not remove them from the specification simply because you dislike the look.
Ask why they are included and whether they are required for the project.
Replacement windows can be more airtight than the old ones they replace, so ventilation still needs to be considered.
The Window Energy Efficiency guide covers this in more detail.
Some openings can form part of the means of escape from a room.
Ask whether any existing windows perform that role and whether the proposed configuration maintains the required opening.
This is especially important if you are changing the size or position of opening sashes.
For many straightforward replacement projects, planning permission is not the main issue.
But listed buildings, conservation areas, Article 4 Directions, flats and significant changes to external appearance can all alter the position.
If there is any uncertainty, ask before ordering.
Our Planning & Conservation guide explains the main situations to check.
Do not assume this without asking.
If the property is listed, within a conservation area or otherwise unusual, establish clearly who is responsible for confirming the planning position and securing any required consent.
That responsibility should not be left vague.
A proper survey helps turn an initial quotation into a confirmed specification.
Ask what the survey covers.
That may include:
If significant changes are found at survey stage, ask how those affect the quotation.
Older homes can reveal issues once openings are inspected properly.
Ask how unexpected findings are handled.
For example:
You should know how changes are agreed before installation begins.
Ask whether installation is carried out by:
The answer does not automatically tell you whether the installation will be good or bad.
What matters is understanding who is responsible for the work and how installation quality is managed.
Clarify whether the quotation includes:
Do not assume every installer includes the same things.
This phrase can mean different things.
Ask what will happen around the opening after the old frame is removed.
Will minor plaster disturbance be repaired?
What happens to exterior render?
Are decorative finishes included?
Will you need a decorator afterwards?
A clearer answer now prevents arguments later.
Maybe.
Replacement frame depths and proportions can differ from the existing windows.
If you have expensive blinds, shutters or fitted interior finishes, raise this before ordering.
The window company may not be responsible for altering them, but they should at least be part of the conversation.
Again, ask.
Some can remain.
Others may need to be altered or replaced.
Bay and bow windows can make this particularly relevant because the interior board may form a noticeable part of the finished space.
Ask for a realistic indication.
The answer will depend on:
A straightforward replacement project and a large bay installation should not be expected to take exactly the same amount of time.
If the work is expected to run over several days, this is a perfectly reasonable question.
You should know how openings are managed at the end of each working day.
Window replacement involves removing part of the building envelope.
There will be some disturbance.
Ask about:
A little preparation can make installation considerably easier.
Installers work in British weather. It comes with the territory.
But severe wind or rain can make certain work impractical or unsafe.
Ask how weather delays are handled and how you will be kept informed if the installation schedule changes.
This is one of the most important questions.
Ask what is guaranteed and for how long.
The answer may cover different parts separately, such as:
Do not assume "10-year guarantee" means every component is covered identically for ten years.
Read what it actually includes.
Establish whether the guarantee comes from:
And ask what happens if you need to make a claim.
Windows may occasionally need adjustment after installation as components settle or are used.
Ask how aftercare works.
Who do you contact?
Is there a dedicated service team?
Are adjustments covered?
What happens if a sealed unit fails later?
You are buying more than the installation day.
Even low-maintenance windows benefit from some care.
Ask about:
If you are choosing between materials partly because of maintenance, the Window Materials guide is worth revisiting.
Ask how long the quotation is valid and what could cause the price to change.
Potential reasons may include:
A clear process for variations is more important than pretending changes can never happen.
Understand:
Do not rely on a verbal understanding of the payment schedule.
If you are considering finance, ask:
Compare the total cost rather than focusing only on the monthly payment.
This can help prevent confusion.
Ask which items are standard and which are upgrades.
These might include:
A quotation should make those distinctions reasonably clear.
Usually, but ask what effect that has.
Removing something useful purely to hit a target price may not be sensible.
Equally, there is no reason to pay for an upgrade that solves a problem your property does not have.
The Window Costs guide explains how to think about value rather than simply reducing the final number.
This is particularly useful when appearance matters.
Ask to see similar examples of:
Real projects show scale and proportion much better than isolated product photographs.
If possible, yes.
Frame thickness, operation, handles, finishes and build quality are much easier to judge in person.
If two products sound almost identical on paper, physically comparing them can make the choice much easier.
This may be the most revealing question on the whole page.
Do not just ask:
Which window is best?
Ask:
Which would you recommend for this house, and why?
A useful answer should refer to things such as:
If the answer is simply that one product is "the best one we sell", you have not really learned much.
This is another good question.
Sometimes understanding what does not suit the property is more useful than being shown ten different options.
A company should be able to explain when a product is unnecessary, inappropriate or poor value for a particular project.
Ask it.
If acoustic glazing, premium hardware or a specialist finish does not provide much benefit in your circumstances, it is useful to know.
The recommendation should fit the home and budget rather than simply maximise the order value.
The reverse matters too.
Perhaps a cheaper colour is noticeably different from the one you really prefer.
Maybe reducing opening sections will make a room awkward to ventilate.
Maybe removing a glazing upgrade means a noisy bedroom remains noisy.
A good discussion should work both ways.
Before accepting the final specification, make sure the important details are recorded.
That should include whichever items apply to your project:
If something matters enough to influence your decision, it should not exist only in a conversation you had three weeks ago.
This is a guide, not an interrogation script.
A straightforward replacement project may not require half of these questions.
The useful approach is to pick the ones relevant to your property.
If you are replacing three simple Casement Windows, you may not need a detailed discussion about planning restrictions, acoustic glass and heritage proportions.
If you are replacing twenty windows on an older property in a conservation area, you probably need considerably more detail.
Use common sense.
If you ask nothing else, make sure you can answer these:
If those twelve answers are clear, you have already removed a lot of uncertainty from the buying process.
The final chapter in the Windows Buying Guide is Window FAQs, where we bring together shorter answers to common questions that do not necessarily need an entire guide of their own.
You can also return to any other part of the guide:
Imagine two quotations that are £1,200 apart.
Without asking questions, the obvious conclusion is that one company is simply more expensive.
Once you compare them properly, you might discover that one includes a coloured finish, laminated ground-floor glazing, different opening configurations and more extensive installation work.
Or you might discover there is barely any meaningful difference at all.
The questions above are what allow you to tell the difference.
You should not feel awkward asking what you are paying for.
A good quotation process should make the project clearer as it progresses, not leave you feeling that you need to nod along with terminology you do not understand.
If a question matters to you, ask it.
The purpose is not to catch anyone out. It is to make sure the finished windows are the ones you thought you were buying.
