FAQs (Frequently asked questions) about composite windows, doors and sliding doors by Westcoast Windows

When you’re choosing windows and doors for your project, whether it’s replacement windows, renovation, new development or self-build, the choice of windows and doors on the market place can be mind-boggling.

There are so many options to weigh up and decisions to make, based on budget, low maintenance, energy efficiency, sound-proofing… the list goes on. If you’re looking at patio doors or French windows, which is best: bifold doors or sliding doors? Are you looking for a painted finish or low maintenance aluminium exterior? A warm wood interior or coloured to suit your decor?

We’ve put together a short list of FAQs on composite windows and doors to help with your decision making process. If you’d like to chat through your project with one of our team, get in touch: info@westcoastwindows.com or call 01359 241944.


Q1: What type of windows and doors are available in a composite construction?

A: Westcoast Windows can make your windows and doors to bespoke sizes and shapes to fit your individual requirements, in a comprehensive range of styles including open out top and side hung windows, projecting and fully reversible models, fixed lights, open in tilt and turn windows, open out and open in hinged balcony doors, terrace doors, access doors, tilt and slide doors and lift and slide doors.


Q2: Which finishes are available with composite windows and doors?

A: Westcoast Window products are manufactured with a low maintenance stylish aluminium exterior that can be finished in a huge range of powder coated colours, including two finishes that mimic anodising which are unique to Westcoast Windows. Your warm wood interior can be finished in a range of paints or lacquers to suit your style, including clean white, clear lacquer, teak, cherry, oak or dark brown. Visit our HOMEOWNER GUIDANCE page to view the range.


Q3: How energy efficient are composite windows?

A: Our double-glazed Classic opening windows are rated with U-values down to 1.4 W/m2 K and as low as 1.0 W/m2 K for our triple gazed Design series. Fixed light windows offer even better performance. The unique construction of Westcoast window and door products means the aluminium and timber are bonded to make a truly composite frame and sash. The timber element acts as a thermal break enabling the frame to offer very high levels of insulation. Westcoast Windows are factory assembled with double or triple glazed sealed units which incorporate the latest ‘warm edge’ technology, insulated super spacers and argon gas filling as standard.


Q4: What type of glazing bars can be fitted with composite windows?

A: Composite windows can be fitted with True Composite Glazing Bars, Bonded (or Duplex) Glazing Bars, Integral Glazing Bars or Clip-on Glazing Bars. Your decision on which is right for you will likely be based on cost, appearance and ease of cleaning. View our article to understand more on glazing bar types and imagery: Composite windows glazing bars


Q5: Are composite windows and doors maintenance free?

A: In short, the answer is almost certainly yes! Westcoast Windows unique composite construction consists of an outer framework of powder coated aluminium extrusions, which are rustproof, resistant to UV rays and harsh weather conditions and eliminate the need to repaint every few years.  The aluminium profiles are specially designed to allow the window frame to be fully drained and ventilated, preventing harmful moisture and rot from damaging the timber. As a result, maintenance is limited to periodic cleaning both internally and externally with water containing a mild detergent and annual lubrication of certain moving parts such as hinges and espagnolette bolt mechanisms.


Q6: Are composite windows sound-proof?

A: Westcoast standard entry level double glazed Classic Series windows offer exceptional, tested sound reduction performance of 35dB (Rw) and 29dB (Rw+Ctr) respectively. Areas of high noise pollution can be better insulated by increasing the thickness of the glass, using acoustic laminated panes or adjusting the size of the cavities between glass panes. Westcoast Windows can offer a variety of tested glass combinations to improve whole window noise reduction up to 48dB Rw. View our datasheet for more information: Westcoast acoustic composite windows


Q7: What is the difference between composite windows and aluminium clad windows (alu clad windows)?

There is a fundamental and important difference between aluminium clad windows and the Swedish unique bonded construction composite windows manufactured by Westcoast Windows.

Aluminium clad windows are basically a standard timber window with a piece of aluminium clipped to the outer face of the window. This creates a gap between the aluminium and timber, allowing air and therefore moisture and dirt to penetrate the timber. As the timber section is indirectly exposed, the aluminium would have to be periodically removed and the timber section refurbished to maximise the life of the windows.

Westcoast Windows’ unique bonded aluminium and timber composite window system uses a high density timber inner section bonded to a powder coated aluminium outer section to create a window with maximum lifespan and minimum maintenance.   The primary benefit of the true composite Westcoast Windows system over aluminium clad windows is that the timber and aluminium is bonded via a butyl tape, which is compressed to eradicate all air. No air means no condensation can build up between the timber and aluminium sections. This creates the added benefit of allowing the window to be sealed in the building at the extreme outside face of the aluminium, meaning no part of the timber section is exposed to the elements. This in turn means the timber section doesn’t need to be preserved, leading to a more environmentally friendly product with a longer lifespan and less maintenance. For further explanation read our news feature:  WHY CHOOSE BONDED ALUMINIUM TIMBER COMPOSITE WINDOWS OVER ALUMINIUM CLAD TIMBER WINDOWS?


Q8: What is the difference between sliding doors and bifold doors?

If you’re looking to install patio doors or French windows you may consider the pros and cons of sliding doors vs bifold doors. Sliding doors offer a larger glass area for uninterrupted views of the outside. Their smooth easy-glide action makes them easy and convenient to use, plus they save space by sliding back on themselves. Bi-fold doors usually have smaller glazing areas and need enough room to allow the panes to flex and fold back to store when open. Both have similar costs, so it’s really a case of what will work best with your project. View our Sliding Doors brochure for more information.


Q9: What kind of glass can I use with composite windows?

A: Westcoast Windows can supply any commercially available type of glass available on the market in order to meet thermal insulation, safety, security, solar control, acoustic, obscure, self-cleaning, fire rating and external condensation requirements. For more information visit our HOMEOWNER GUIDANCE page and scroll down to the GLASS section.


Q10: What are SBD certified windows?

A: The SBD (Secured by Design) initiative is a quality standard for burglar-proof products, developed by the PCPI (Police Crime Prevention Initiatives) to create secure windows and doors that reduce the risk of intrusion by 75%. Westcoast Windows are a SBD license holder, which demonstrates not just successful testing to PAS 24:2016 but also regular independent UKAS accredited 3rd Party auditing to ensure consistency of product quality and performance and evidencing compliance with Building Regulations Approved Document Q – Security. For more information read our Part Q feature: WHAT IS PART Q AND HOW DOES IT APPLY TO COMPOSITE WINDOWS AND DOORS FOR A NEW BUILD


Q11: What kind of warranty is available with composite windows?

A: Westcoast Windows strive to provide the best quality products that are covered by our 10 year guarantee, with 10 years also available on glass from the date of manufacture. This is of course providing the windows have been cared for and not misused – see our Aftersales page for more information.


Q12: Are composite windows environmentally friendly?

Only PEFC (www.pefc.org) timber is used in the construction of Westcoast window and door products. Frame and sash profiles use laminated timber sections in order to reduce waste and improve stability of the finished product, whilst the composite construction eliminates the need for impregnated timber and therefore no harmful chemicals are used in the manufacturing process. Only water based paints and stains are applied to finish timber surfaces.

The external aluminium provides significant additional strength reducing maintenance requirements and extending the anticipated service life to over 50 years. The aluminium extrusions are manufactured from a minimum content of 15% recycled material and are 100% recyclable.

The double and triple glazed sealed units are supplied with the latest high performance low emissivity coatings, argon gas filling and composite insulated super spacers for maximum thermal insulation performance. Harmful heavy gases such as SF6 are never used in Westcoast products. (please see Q3 for the full energy efficiency information).

View Westcoast Windows’ full environmental policy here: Westcoast Environment & Sustainbility


For more information about our Swedish designed and manufactured composite windows, doors and sliding doors visit our website: www.westcoastwindows.com

Visit our INSPIRATION gallery for lots of great ideas for your project or see our PINTEREST page.

If you’d like to chat through your project with one of our team, get in touch: info@westcoastwindows.com or call 01359 241944

FAQs (Frequently asked questions) about composite windows, doors and sliding doors by Westcoast Windows