composite windows vs upvc


(Accurate at time of publishing)

As manufacturers of Swedish true bonded aluminium timber composite windows and doors, we’re often asked why customers should choose composite windows over uPVC or plastic/wood alternative windows.

There are so many options to consider when choosing windows for your home, it can be confusing comparing the costs, materials, energy efficiency, environmental benefits, plus the best solution to add value and aesthetic appeal to your property.

Here’s a quick guide to the pro’s and con’s of each to aid your decision making:


PLASTIC/WOOD ALTERNATIVE WINDOWS – Plastic/wood alternative windows are considered to last only 20-25 years, maybe 30 years maximum. They also tend to be lightweight and less robust than composite windows, and often have to be strengthened with a metal core. Due to this there are size limitations as the frames are often prone to sagging. Temperature variations can cause expansion and contraction of the framework, which can lead to issues with weathertightness.

COMPOSITE WINDOWS – Industry professionals suggest composite windows have a lifespan of 40 to 50 years or more with regular cleaning and annual maintenance, including lubrication of moving parts – twice as long as plastic/wood alternative windows. Westcoast Windows high performance composite windows are designed and manufactured in our factory in Sweden, with a unique bonded aluminium and timber composite construction.  Westcoast Windows provide a comprehensive 10 year guarantee on our windows and doors, including glass, ironmongery and all components. For more info see our FAQs page.


PLASTIC/WOOD ALTERNATIVE WINDOWS – Plastic/wood alternative windows are not bio-degradeable and although steps are being taken to improve and increase recycling facilities, only a small proportion of windows are being recycled and many end up in landfill. They are manufactured from unsustainable resources, and available studies still show considerable concerns about the impact on the environment of plastic windows, particularly the consumption of fossil fuels, human toxicity, energy and emissions in manufacture and the toxic legacy of recycling.  Further reading available from The Alliance for Sustainable Building Products and The Wood Window Alliance:

A clear choice WWA WWF 10.5.17.pdf

COMPOSITE WINDOWS – Due to their aluminium and timber construction, our composite windows are fully recyclable. Westcoast Windows composite windows‘ aluminium exterior is finished in a powder-coated colour which is environmentally friendly and virtually pollution-free. Due to our unique window construction we don’t need to rely on preservatives to treat our internal wood finish, only water-based lacquer or paint. We are committed to using only energy efficient sustainable materials that can be recycled or disposed of by environmentally friendly methods. Westcoast Windows use PEFC certified wood, which guarantees that it comes from renewable sources.  View our Environment & Sustainability statement here: Westcoast Environmental.pdf

Furthermore, in the case of Westcoast Windows’ composite products, our manufacturing facilities are based in Trollhättan on the West coast of Sweden where residents and commercial businesses benefit from many years of investment into sustainable energy technology. The local heating system recovers excess energy from industrial activities which is recycled and complemented with local biomass production to heat the whole city. Westcoast Windows’ waste timber contributes to this renewable energy source. Power generation is principally from Trollhättan’s own hydro-electricity plant, supplemented by local wind farm and solar energy sources with occasional nuclear support at times of exceptional demand.

composite windows vs upvc
composite windows

Industry professionals suggest composite windows have a lifespan of 40 to 50 years or more with regular cleaning and annual maintenance

aluminium wood composite windows for eco house
aluminium wood composite windows for eco house
composite windows for new build

Our 48mm triple-glazed Design Series offers U-values as low as 0.9 W/m2k for fixed glazing.


PLASTIC/WOOD ALTERNATIVE WINDOWS – Although plastic/wood alternative windows enjoy a reputation of being long-lasting and requiring little or no maintenance, this has often proven unrealistic, as they need to be cleaned every six months or they become irreversibly discoloured by dirt. They can also turn yellow and brittle in sunlight and can even develop hairline cracks. Once degraded in this way, uPVC frames are difficult, if not impossible to repair.

COMPOSITE WINDOWS – Our composite windows and doors are constructed of an aluminium exterior, powder-coated in a colour of your choice, therefore no exterior painting is required. Maintenance just involves occasional cleaning with a soft cloth, luke warm water and a few drops of mild detergent, plus annual lubrication of certain moving parts. The authentic warm wood interior is coated in a water-based lacquer or paint.  The aluminium outer and wood inner are divided by high performance butyl tape, compressed to eradicate air and thus prevent the risk of condensation. This means no timber is exposed externally, ensuring a longer lifespan and minimum maintenance. The regular maintenance cycle will ensure your windows retain their look and function for many years to come. Take a look at the colour finishes available for the low maintenance power-coated exterior: STYLES & OPTIONS


PLASTIC/WOOD ALTERNATIVE WINDOWS – Plastic/wood alternative windows do offer good energy efficiency. If you decide on this option, ensure your supplier can provide the energy ratings of their windows – often they are registered with the British Fenestration Rating Council.

COMPOSITE WINDOWS – Our unique bonded construction offers exceptional energy efficiency, thermal insulation, weathertightness and acoustic benefits. Our 48mm triple-glazed Design Series offers U-values as low as 0.9 W/m2k for fixed glazing. Our Classic Series and more traditional looking Antik Series are available in 28mm double glazed or 36mm triple-glazed, all offering exceptional U-values. Take a look at our full range of composite windows, doors and sliding doors: PRODUCTS.


PLASTIC/WOOD ALTERNATIVE WINDOWS – White plastic windows generally have thicker frames that affect the appearance of the window, allowing less light into your home and lighter coloured frames can discolour, turning yellow or stained. However some of the new developments in wood alternative windows are more appealing and can improve the aesthetics of your home.

COMPOSITE WINDOWS – The construction of composite windows and doors allow for slim frames and larger glazing areas to maximise the light into your home – this is particularly the case with our triple-glazed Design Series which is ideally suited for use in contemporary architecture. Composite windows, doors and sliding doors offer greater flexibility, allowing you to specify larger windows and doors (our largest sliding door is 6m x 2.4m). The stylish low maintenance aluminium exterior can be finished in a wide range of standard RAL colours or bespoke to your preference. The interior is constructed of real wood, available in knot-free laminated pine, oak or alternative species, offering a warm authentic feel indoors. Take a look at the colours available in STYLES & OPTIONS.


PLASTIC/WOOD ALTERNATIVE WINDOWS – While the lower initial capital cost of plastic/wood alternative windows may be tempting, they are likely to need replacing more frequently than composite windows and require regular maintenance to keep them looking good and functioning properly.

COMPOSITE WINDOWS – While composite windows are not the most expensive option on the market, the initial investment is likely to be more than plastic/wood alternatives. However when you consider they are longer lasting than plastic/wood alternatives, require minimal maintenance, look attractive and have a genuine wood interior, plus potentially increase the value to your home, we believe they are worth the initial outlay. Why not contact our team to have your project priced up – you might be surprised that they’re not as expensive as you may think! Email the team at:


Composite windows benefits

  • Fully recyclable
  • Environmentally friendly
  • Energy efficient
  • Sustainably sourced
  • Low maintenance
  • Cost efficient over their lifetime
  • Stylish and enhances the value of your home
  • Authentic – real wood

To discuss your project and how Westcoast Windows Swedish composite windows and doors are the perfect choice, contact our team on 01359 241944 or email us at

For more information on the construction of our composite windows and doors visit MADE IN SWEDEN.

Read how Westcoast Windows were the ideal environmentally friendly glazing solution for this eco house holiday home in Cornwall: CONTEMPORARY ECO HOUSE

Brochure Downloads