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If you’re building a new house, or renovating an older property with poor-quality glazing, one of your initial questions will likely be ‘how much do new windows cost?’ and ‘what should I budget to install them?’
Window prices will depend on a variety of factors, from the size of the panels through frame materials, glazing options, colour finishes, installation details and more. Of course, window costs count for a substantial chunk of any UK home building project – potentially accounting for around 5%-10% of a typical self builder’s total construction budget.
Your glazing will also likely play a key role in the architecture and overall quality of your house – with many modern design features revolving around glass features. So, it’s worth spending plenty of time at the research stage to ensure you’re investing in quality and the necessary add-ons to ensure a cohesive scheme that performs well for years. Poor-quality windows will not only compromise the look, but they’ll also fall down in terms of durability and longevity. “Generally the better-performing the window is in terms of insulation, airtightness and security, the more it will cost,” Dan Todd, sales director at Kloeber.
So, what other factors influence window costs? We’ve spoken to UK window suppliers and the Build It Estimating Service to break down the considerations in detail and help you better understand how much to budget for your windows. The window cost information given here is intended as a guide only – but it will be a useful reference point when obtaining specific quotes for your project.
When researching how much windows cost, remember that it’s worth paying extra for a first-class, high-quality window – and there are options across the board in terms of PVCu, softwood, hardwood, aluminium and composite products. “The standard of the manufacturing process can vary massively, both across the UK and abroad, so make sure you do your research,” says Adrian Wild from the Build It Estimating Service.
In the PVCu sector, for instance, the quality of the blending, extrusion, injection moulding, foil finishing, colour matching and other criteria will all make a significant difference to the lifespan and therefore future maintenance and replacement costs.
This Build It Award-winning timber alu-clad design from Norrsken is a practical and stylish casement option, manufactured to operate smoothly throughout the entire lifecycle of the product
When it comes to understanding what you’re getting for your money, look at the obvious requirements first. “Does the manufacturer’s warranty extend to at least 10 years, for instance? It’s also important to check if the window warranty includes any cover on finishes and fittings,” says Adrian.
Other questions to ask include whether the products carry a BSI Kite Mark and have been assessed by the British Board of Agrement (BBA). Check, too, if the manufacture and supply is carried out under the ISO 9001 quality management system. Ask for evidence that the window system you’re buying is properly tested in terms of delivering on the performance standards you need, too.
Security is governed by Part Q of the Building Regulations, for instance, and references British Standard PAS24. The latest version is PAS24:2022+A1:2024, and new window products will be tested to this standard. It’s also worth noting that not all windows have to meet Part Q requirements, as the regulation doesn’t apply to replacements or extensions.
Finally, be sure you understand the level of service you’re getting from the window supplier before you buy. Ask questions such as:
The list goes on. Only once you’ve got the complete picture can you then compare window quotes like-for-like.
Trickle vents, triple glazing, solar control glass, colour upgrades, heritage glazing bars, super-slim frames and lifting equipment can all change the final cost (keep reading for more on these elements). Installation is additional, and window replacement projects may also involve removal, disposal, making good and repairs to surrounding finishes.
| Frame material | Typically supply-only starting price | Notes |
|---|---|---|
| PVCu, white | From £800 | Entry point for better quality PCVu systems |
| PVCu, timber effect | From £920 | Premium for replica finish |
| Aluminium | From £1,015 | Slim sightlines and great stability |
| Softwood timber | From £1,150 | Versatile option for character and performance |
| Hardwood timber | From £1,250 | Greater durability and rich natural finish |
| Accoya timber | From £1,535 | Premium option; strong durability and stability |
| Alu-clad softwood | From £1,280 | Low-maintenance external finish |
These figures are indicative, supply-only starting points for a good-quality 1,200mm x 1,200mm double-glazed, double-opening casement window meeting current Building Regulations, excluding VAT and installation.
The biggest differentiator when it comes to window prices is the material used for the frame. “In general, PVCu is the cheapest option, followed by aluminium, softwood, hardwoods and then alu-clad and steel at the top end,” says Dan from Kloeber.
In the past, engineered softwood was typically more cost-effective than aluminium – but materials inflation has affected some products more than others. There will always be some variation, of course, and much depends on the overall quality of the product, design and specification you choose. For instance, a number of PVCu sash window replacement specialists have entered the market in recent years, using the latest tech to deliver very good replicas of timber heritage windows.
These Origin aluminium windows combine strength with a slim, sleek design. The minimal frame offers maximum light flow and minimal sightlines, while prioritising security and thermal efficiency – achieving U-values as low as 1.2W/m²K
Similarly, Internorm offers a range of high-spec PVCu options (as well as PVCu-aluminium and timber-aluminium solutions) that rival other materials for style and performance. Such products will have a price tag to match their quality.
There’s a host of considerations to account for when choosing between different frame materials, but here’s a quick rundown of the major factors for the four most popular options:
PVCu is the cheapest option up front, but there’s a huge variance in prices depending on the window system’s quality. It is low maintenance, but generally not as durable as the alternatives. Once they deteriorate, they’ll probably need to be replaced rather than repaired, increasing whole-life costs.
Softwood windows can offer a very good lifespan, although they will need more maintenance than PVCu. Look for products that provide a lengthy warranty on
the factory finish (six years is commonplace on stains; longer on paint) to reduce ongoing costs for upkeep. Fluctuating materials costs mean engineered softwood window prices are currently slightly higher than aluminium windows.
Hardwood is a slow-growing and expensive material, so the initial costs for windows in this material will be greater. However, you get the benefit of a very stable timber window offering excellent durability. As with softwood, these units come with protective coatings to maximise the lifespan.
Aluminium windows are ultra-low maintenance thanks to their corrosion resistant coatings, meaning the frame is easy to care for. The metal will not swell, crack, split or warp over time; ensuring an extended product life. Their growing popularity makes them competitive price-wise.
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Depending on the product line, you may have the opportunity to choose pretty much any colour you like – or you might be limited to a particular palette.
Whether there’s a surcharge for more unusual shades and finishes will come down to the frame material and the supplier’s process. “With aluminium windows, off-the-shelf colours are typically cheaper than special shades – although this does depend on the manufacturer,” says Dan. “With timber, the painting process is different so it’s generally the same cost, whatever RAL colour you opt for.”
Metallic and textured finishes on aluminium windows also generally cost more, as do the higher-quality timber lookalike surfaces on plastic products. “Bear in mind that standard colours usually also have a quicker lead time,” says says Edward Stobart, technical sales manager at IDSystems. This could help support a swifter, more cost-effective build.
These stylish triple-glazed casement windows from 21 Degrees feature a dual finish, with a striking green chosen externally for added wow. The range can achieve U-values down to 0.80 W/m²K
Dual-colour finishes are now very popular among self builders and renovators. For instance, at Build It’s Self Build Education House, we chose a stylish grey-green paint externally, and lacquered timber internally to add warmth and character to the living spaces. A dual-colour finish might add around 15% to the base cost of an aluminium window. However, there’s generally less of a price uplift for dual-colour finishes on timber or alu-clad composite products.
Sales director at Kloeber
Managing director of HBXL Building Software
Technical sales manager at IDSystems
The makeup of the window is important when it comes to the price. “In general, having fewer sections is cheaper than opting for multi-section windows,” says Edward.
Like-for-like, fixed pane windows (sometimes referred to as picture windows) will always be the cheapest option, as there are no additional moving parts to pay for. There’s typically very little cost difference between top-hung and side-hung casement windows, as the components are very similar. However, tilt-and-turn mechanisms where the windows can hinge in two directions (typically inwards as a side-hung casement and tilting from the bottom to provide secure ventilation) will cost slightly more.
Winner of Best Casement Window at the 2024 Build It Awards, the Aura Plus casement window from Rationel is available both double glazed and triple glazed, with U-values down to an excellent 0.75 W/m²K
A good example is designs with fanlights (aka toplights) above the main panes. The smaller upper windows could be top-hung openers, but it will be cheaper to go for fixed panels. You then have the choice of whether to use dummy sash fanlights to match the profile of the opening panels; or opt for direct glazed panels beaded directly into the frame.
“This is something we considered with the Build It team for the Self Build Education House, and we ended up going with direct glazing to reduce the frame and let more light in,” says Dan. “A general rule of thumb is less frame and more glass will keep costs down.”
Case study Contemporary timber-clad home built on a rural family farm in Kent
Freddie and Katie Pack saved up to build this contemporary and efficient house on their family’s Romney Marsh farm after living in a small cabin a few fields away. They set out to renovate an existing 1950s brick house on the plot, but soon realised it would be easier to knock down and self build a new home. The couple enlisted the help of Rob Pollard, of local practice RX Architects, to draw up plans. “The brief was to create an adaptable and practical country home. The design needed to suit Katie and Freddie’s lifestyle now, but also with the potential to adapt as they grow as a family”, says Rob.
Photo: Richard Gadsby
“A boot room, utility space and office were all essential for them, but still keeping bright, open and fun internal main living spaces. The design also incorporated high levels of insulation, triple glazing and an air source heat pump, resulting in a low-energy property with minimal long-term running costs,” says Rob.
Photo: Richard Gadsby
The project came in pretty much on budget, with the only overspend being on the garage. Insuring the build was straightforward too, because they tied it into the existing NFU farm policy. Outside, the property is clad in Siberian larch, with charred sections on the lower level. “I was used to working with larch and we went for shadow gaps rather than rebating. We had to put a black felt wrap on the exterior, followed by batons, a double skin of UV facade felt and then the cladding,” he adds.
The 175m² build cost a total of £350,000 (£2,000 per m²), with the external walls and windows making up 13% of the total spend, at £45,000 (£257 per m²). The triple-glazed windows and glazed doors are from Norrsken.
| Location | Kent |
| Construction method | Timber & steel frame |
| Project route | Commissioned Architect & tendered to own builder contacts |
| House size | 175m² |
| Build cost | £350,000 (£2,000 per m²) |
| Building work took | 50 weeks |
Triple glazing requires an extra pane of glass – so in theory it should be about 50% more expensive than double glazing (minus any economies of scale). That rings true with Kloeber’s ballpark costs: they put standard double glazing at around £157 per m² (for the glass panels only); and standard triple around £261 per m² (an uplift of over 60%).
Of course, you might then choose to increase the spec of these with features like inert gas fillings to improve thermal performance or special coatings for particular applications.
“While triple glazing costs more than double glazing, at around £30-£40 per unit, the long-term benefits can make this a worthwhile investment,” says Jo Trotman, sales and marketing manager at The Residence Collection. “With improved thermal efficiency and u-values as low as 0.76 W/m²K on our Residence 9 system, triple glazing can help reduce heat loss and potentially lower heating costs over time.”
In recent years, many suppliers have pushed triple glazing with marketing offers, such as triple glazing for the price of double glazing, to encourage more people onto this specification – presumably with the goal of increasing the future market share for triple glazing. This could deliver a significant saving on the right project – but, as with any home building purchase, do your due diligence before signing up, to ensure you are happy with the quality of the window you’re getting.
A low-e (low-emissivity) coating is a special finish that reduces heat loss through a window pane. It does this while still allowing the passage of visible light – delivering excellent thermal performance without impacting on natural brightness.
In the past, low-e (low-emissivity) coatings were a premium upgrade for improving the efficiency of glazed products. These days, however, low-e comes as standard and won’t add to your window prices. “A low-e coating is mandatory on any glass now, in order to pass modern Building Regulations,” says Dan.
Susan and John Shearer‘s self build in the Cairngorms National Park features bespoke triple-glazed curved windows, specially made by Nordan. They are weather protected by generous eaves, but also covered in aluminium facings externally for minimum maintenance. Photo: David Barbour
The excellent overall efficiency of modern homes means designers, manufacturers and installers are now often more concerned about excess heat gain through windows. That’s where solar control coatings come in. If you have large swathes of south-facing windows, a solar control upgrade will reduce the amount of incoming solar gain and minimise the risk of summer overheating. Expect to pay about 15% on top of your baseline window cost for solar control glass.
Another common requirement is privacy or opaque privacy glass. This is often a planning requirement for windows on side elevations, and sometimes useful for bathrooms and other zones. The cost of privacy glass varies depending on the manufacture and type of finish, but coatings might add anywhere from £10-£100 to typical window prices. Expect to pay a significant premium for electric smart glass.
Depending on your project, Building Regs may require you to include trickle vents within window and door frames. “Trickle vents will always add to the price of your windows,” says Dan. “How much is very product dependent, as some items need to be manufactured differently to accommodate the vents.” So, you might pay as little as £20 for trickle vents, potentially rising to £100s if it’s a large unit that needs extra framework to accept the vent.
Sales and marketing manager at The Residence Collection
Many companies offer a supply-and-fit service, with labour split out in your quote – so you can see exactly what it costs. As a rough guide, on the Build It House, about 20% of the price of our windows, French doors and front door went into installation.
One top tip is that you’ll get a better price if you buy more windows; especially on the installation side. “It is typically not cost effective for a window company to fit less than four windows on a project,” explains Edward. “As a reference point, for four of our (IDSystems) 2,400mm (W) x 1,200mm (H) aluminium windows, installation would cost around £250 per window, when installing at least four windows.”
It’s important to note that style of window will impact the installation costs. “Standard PVC casement windows are generally more affordable, while options such as flush windows and bay windows can require more detailed installation and precise alignment,” says Jo from The Residence Collection. “Factors including window size, labour, addition of Georgian bars, choice of hardware, specialist glazing, installation height and the condition of the existing structure can all affect the final price. For this reason, we recommend obtaining two or three quotes from experienced professionals before making a decision.”
Another key element to factor into the total price is access to the site – in particular, whether new or amended scaffolding will be required. Note that if you’re replacing existing windows, the openings may need preparing and redecorating by your builder at additional cost.
‘Should I repair or replace my home’s windows?’ is a question many of those undertaking a major renovation project will ask themselves. Your home’s windows are a vital part of its character, so if you’re tackling a renovation project and your fenestration needs attention, deciding on exactly how to proceed and whether to specify a window replacement is not something to be taken lightly.
Knowing whether to replace windows isn’t straightforward and will vary by type, house and age. Some warning signs to look out for include:
As part of their listed home renovation, Mark Camillin and Liam Denny replaced the original home’s single-glazed windows with conservation double-glazed hardwood models, alongside installing heritage-style aluminium bifolds and French doors. Photo: Richard Downer
The cost of buying a brand-new window for replacement purposes should be very similar to buying a window for a new house. So, in terms of indicative pricing for the units themselves, you can use the table for new window costs in this article.
The key differentials will come in terms of the labour involved in removing and disposing of the old window or windows, prepping and/or repairing openings, and any unusual requirements in terms of size and style. As a result, it will usually cost slightly more to completely replace an existing window than to install one in a new opening.
Rebecca Clayton is communications director at IQ Glass, one of the UK’s leading architectural and structural glazing companies specialising in bespoke projects.
The best savings usually come from simplifying the design, not reducing the quality. Using fixed windows where openings are not needed, reducing complex window arrangements and avoiding shaped windows can all help control costs without detracting from the design. Also ensure you are not over-specifying; you don’t always need triple glazing to get the thermal performance needed and nor do you need it for good acoustic reduction if you are using high quality glass. If you tell your supplier what performance standards you need to achieve they can advise the best way to get there.
Silicone sealed, insulated glass units and structurally bonded systems are well worth the investment if you are looking for high quality with slim frames. Bonding the glass onto the frame increases the strength of the opening, creating a durable window, with a much slimmer design. The silicone seal on the windows also creates a more robust window seal than your typical hot wax seal which most uPVC or casement window systems might use, meaning the units last longer.
All made-to-order windows are technically bespoke, but you should look for a window system that is fully designed and has been tested extensively. Budgets vary widely depending on the frame material, glass specification and size. The best way to get a good understanding of what you should budget is to get a supplier involved from an early stage; they can then advise on the cost of what you want to achieve and can offer guidance on how to alter the design to meet your budget requirements.
The greatest impact usually comes from large panes of glass, slim sightlines and simple glazing layouts. Frameless picture windows, floor-to-ceiling fixed glazing and slim sliding glass doors can completely change how a space feels. To control budget, focus the highest specification glazing on the key areas, such as the main living space, garden elevation or important view, then you can opt for a simpler system elsewhere.
The best approach to balance performance and budget is to make sure you are not over-specifying the glazing. You don’t have to throw big glass specifications at a window to get the performance you need. Most don’t know that the U-values (a measurement of energy efficiency where smaller numbers mean better performance) are lower on larger windows compared to smaller windows. This is because in many instances, the glass has better insulating properties than the frame.
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