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What changes the price of triple glazed windows?
The price of triple glazed windows depends on the frame material, the number, size and style of windows, the glass specification, the fitting and making good, and whether the frames can take the extra weight of a third pane. This page does not print a price, because we could not find two dated public sources that agree on one.
Last reviewed:What triple glazing is
A triple glazed window has three panes of glass in a sealed unit, with two gaps between them, instead of the two panes and one gap of double glazing. The gaps are usually filled with an insulating gas, and the glass may have a coating that reflects heat back into the room. The aim is to let less heat escape and to make the inside surface of the glass feel warmer.
QuoteZila is starting in Cheshire, with Crewe, Nantwich and Sandbach among the first towns, and anyone in the UK can post a job. We have not put a price on this page. The figures we found came from window companies and other sites we cannot link to as dated public sources, and they varied widely. This guide covers what changes the price and how to compare quotes.
The Energy Saving Trust says upgrading glazing, such as to double or triple glazing, reduces draughts, cold spots and condensation [S1]. How much difference triple glazing makes over good double glazing depends on your home.
Triple or double glazing?
Triple glazing is not automatically the right choice for every window. Things that affect the decision:
- What you have now. Replacing single glazing or old, failing double glazing is a bigger change than replacing modern double glazing that still works.
- Which way the windows face. North-facing rooms lose heat without much sun gain, while south-facing glass gains heat from the sun.
- Noise. Some triple glazed units help with outside noise, but the glass specification matters more than the number of panes. Acoustic laminated glass is a separate option.
- Weight. A third pane makes the window heavier, which affects frames, hinges and large opening sashes.
- Other insulation. If the walls and loft are poorly insulated, windows are only part of the picture.
- Plans for the house. A wider retrofit or a heat pump may make the extra performance more useful.
Ask each installer to give you the performance figures for their double and triple glazed options for your actual windows, so you can compare like with like.
Frames and styles
The frame and the way the window opens shape the price as much as the glass does:
- uPVC frames are widely available and usually the starting point for comparison.
- Timber frames suit older or period homes and need repainting or treating over their life.
- Aluminium frames have slim sightlines and are often used for large panes and doors.
- Composite frames combine materials, such as timber inside and aluminium outside.
Opening styles include casement windows, tilt-and-turn windows, sash windows and fixed panes. Sliding sash windows with triple glazing need careful design because of the weight. Ask each installer which frames and styles they offer with triple glazing, and whether they make them or buy them in.
What changes a triple glazing quote
| What changes | Why it matters | What to ask |
|---|---|---|
| Number and size of windows | More and larger windows mean more glass and more fitting time | How many windows, and what sizes? |
| Frame material | uPVC, timber, aluminium and composite differ in cost and finish | Which frame, which maker, and what colour? |
| Opening style | Tilt-and-turn, sash and large casements need stronger hardware | Which styles, and are they made for triple glazing? |
| Glass specification | Coatings, gas fill, spacers and safety glass vary | What is the full glass specification? |
| Performance | Units differ in how much heat they let through | What are the performance figures for these windows? |
| Removal and disposal | Old windows have to come out and be taken away | Is removal and disposal included? |
| Making good | Reveals, sills and plaster may need repair after | Is making good inside and out included? |
| Sills and trims | New sills, cills and trims finish the job | Are new sills and trims included? |
| Access | Upstairs windows and awkward sites take longer | How will you reach the upper windows? |
| Ventilation | Trickle vents or other ventilation may be needed | How will the rooms be ventilated? |
| Certification | The installer should register the work | Which scheme are you registered with? |
| VAT | Register if taxable turnover for the last 12 months goes over £90,000 [S5] | Does the total include VAT? |
If one quote is much lower, check the glass specification, the frame maker, making good and certification. Those lines explain most differences.
Building regulations, FENSA and safety glass
Replacement windows are covered by the building regulations. The Planning Portal says building regulations have applied to all replacement glazing since 1 April 2002, covering thermal performance as well as safety, air supply, means of escape and ventilation [S2]. It says safety glazing is needed in critical locations, such as glass in a glazed door within a set height of the floor [S2].
Most homeowners meet the rules by using an installer registered with a competent person scheme. FENSA says its certificate is proof that a replacement window or door installation complies with building regulations, and that without one you may need to pay for a building control inspection [S3]. FENSA also says it does not cover windows in new conservatories, porches, new builds or extensions, or repairs where the frame is not replaced [S3].
GOV.UK: building regulations approval. QuoteZila is not affiliated with this organisation.
Ask each installer which scheme they belong to, and keep the certificate with your house papers. You are likely to need it when you sell.
Living with new windows
New windows change how a room behaves, and a few points are worth asking about:
- Ventilation. Tighter windows let in fewer draughts, which also means less background ventilation. Ask how the rooms will be ventilated, and keep any vents open.
- Condensation. Moisture from cooking, showers and drying clothes still needs to go somewhere. Extractor fans and opening windows help.
- Cleaning. Ask whether the windows tilt or open inwards for cleaning upstairs, and how to clean the frames and seals.
- Hardware. Hinges, handles and locks need occasional checking, especially on heavy opening sashes.
- Misting. If a unit mists up between the panes later, its seal has failed. Ask what the warranty says about failed units.
- Paperwork. Keep the certificate, the warranty and the glass specification together with your house papers.
Listed buildings and conservation areas
If your home is listed or in a conservation area, changing windows can need consent or planning permission, and triple glazed units may not suit traditional frames. Ask your council before you order. Secondary glazing, a separate pane fitted inside the existing window, is sometimes an option where the original windows need to stay.
Before you ask for quotes
You will get more useful quotes if you:
- List each window, with rough sizes and the room it is in.
- Photograph each window from inside and outside.
- Note any problems, such as misting between panes, draughts, rot or condensation.
- Decide on frames and colours, or ask for options.
- Think about opening styles, including fire escape windows in bedrooms.
- Check your house's status, such as listing or conservation area.
How to compare triple glazing quotes
Citizens Advice says a quote is a fixed price, while an estimate is only a guess [S4]. It suggests written quotes from at least three traders, and says some traders charge for a quote, so ask first [S4]. For windows, ask each quote to state:
- Every window, with size, style and opening.
- The frame material, maker and colour.
- The full glass specification, including any safety glass.
- The performance figures for the windows.
- Removal and disposal of the old windows.
- Making good, sills, trims and decorating.
- Ventilation, such as trickle vents.
- Certification, and which scheme the installer belongs to.
- Any written warranty on the frames, glass and fitting.
- Whether VAT is included. A business must register for VAT when its taxable turnover goes over £90,000 [S5].
Be wary of high-pressure sales visits or prices that drop sharply if you sign on the day. Take time to compare written quotes.
Jobs you might post
These are examples, not taken from real job posts.
- "Replacing eight old double glazed windows that have misted. Looking at triple glazed uPVC. Semi-detached house."
- "North-facing bedroom and landing windows feel cold. Want quotes for triple glazing on those windows only."
- "Timber sash windows in an older house. Interested in triple glazed timber windows if suitable, or other options."
Say how many windows, the frame you are thinking of, whether the house is listed or in a conservation area, and any problems with the current windows.
Get quotes for triple glazing
Describe the windows and your postcode. Up to five matched local businesses can send you a quote [QZ2]. QuoteZila is free for customers and local businesses [QZ1].
Honest status: QuoteZila is new. We're starting in Cheshire, beginning with Crewe, Nantwich and Sandbach, and growing area by area. Anyone in the UK can still post a job or register a business. How fast you get quotes depends on how many local businesses have joined near you. Businesses can register and receive jobs straight away. We don't check insurance, qualifications or registrations, so please check these yourself before you hire.
Posting a job is not open yet
See our glaziers and builders pages for the trades involved.
Questions about triple glazing prices
How much do triple glazed windows cost?
This page does not print a figure. The frame material, the number and size of windows, opening styles, the glass specification, removal of the old windows and making good all change the total. Ask installers for itemised written quotes for the same windows and the same specification.
Is triple glazing worth it over double glazing?
It depends on your home, your current windows and your plans. The Energy Saving Trust says upgrading glazing, such as to double or triple glazing, reduces draughts, cold spots and condensation. Ask installers to compare the performance figures of their double and triple glazed options for your windows.
Do new windows need building regulations approval?
Yes, replacement windows must meet the building regulations. The Planning Portal says building regulations have applied to all replacement glazing since 1 April 2002, covering thermal performance, safety, air supply, means of escape and ventilation. A registered installer can self-certify the work.
What is a FENSA certificate?
FENSA says its certificate is proof that a replacement window or door installation complies with building regulations. If your installer is not registered with FENSA or another scheme, you may need to pay for a building control inspection. Ask which scheme the installer uses before you sign.
Are triple glazed windows heavier?
Yes. A third pane adds weight, so frames, hinges and fixings have to be designed for it. Ask installers whether the frame and opening style they propose are made for triple glazing, especially for large opening windows.
Should I get more than one quote?
Yes. Citizens Advice suggests getting written quotes from at least three traders, and says a quote is a fixed price while an estimate is only a guess. Make sure each quote is for the same windows, frames and glass.
Does QuoteZila check the businesses?
No. We don't check insurance, qualifications or registrations, so please check these yourself before you hire. You can report a quote or a business from your job page.
This page is general information, not professional or legal advice. QuoteZila does not check Gas Safe, WaterSafe, NFRC, NICEIC or other registrations against the register on your behalf: look them up yourself.
Part of Cost guides. All services
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Related pages
- UPVC Bay Windows: What a Quote Should Name. A UPVC bay quote in Cheshire should name the projection, the corner posts and whether a new bay counts as an extension. Ask who carries the wall above.
- Velux Window Work in Cheshire: What to Ask. A standard roof window is around £980 to £1,200 in the Federation of Master Builders loft guide of 3 September 2025. QuoteZila does not set prices.
Sources
- QZ1: QuoteZila product fact. QuoteZila home and jobs-for-tradesmen copy.
- QZ2: QuoteZila product fact. QuoteZila FAQ and app README.
- S1: Energy efficient windows and doors, Energy Saving Trust. Accessed 2026-10-25. https://energysavingtrust.org.uk/home-energy-efficiency/energy-efficient-windows
- S2: Doors and windows: building regulations, Planning Portal. Accessed 2026-10-25. https://www.planningportal.co.uk/permission/common-projects/doors-and-windows/building-regulations/
- S3: Homeowners, FENSA. Accessed 2026-10-25. https://www.fensa.org.uk/homeowners
- S4: Before you get work done on your home, Citizens Advice. Accessed 2026-10-25. https://www.citizensadvice.org.uk/consumer/getting-home-improvements-done/before-you-get-building-work-done/
- S5: Register for VAT, GOV.UK. Accessed 2026-10-25. https://www.gov.uk/register-for-vat