IB Windows supplies and fits flush sash, casement and tilt & turn windows, composite, French, patio and bi-fold doors, AluK aluminium windows, doors and shop fronts, roof lanterns and conservatories across Cardiff and South Wales. They're A-rated, PAS 24 secure and made in Britain.
There are 16 ranges: uPVC on the ADVANCE 70 system and aluminium on AluK systems, all made in Britain. Pick a style, choose your colour and glazing, and we'll survey, make and fit it.
They look like traditional timber but need none of the upkeep. The sash sits level with the frame. Choose an 80mm frame for period homes or 70mm for a sleeker modern finish, with Georgian bars or square lead as options. They're the right choice for Cardiff's Victorian terraces.
WindowsThe UK's most popular window. It works for refurbishments and new builds, with multi-chambered frames and A-rated glass.
WindowsTilt it in for secure ventilation, or turn it fully open to clean it from inside. It's ideal for flats, upper floors and fire escape routes.
WindowsThey add light and floor space and give a front elevation real character. Each one is made to measure for your existing bay.
DoorsGRP composite front doors are tougher and warmer than solid timber. They come in traditional and contemporary styles with decorative, obscure or clear glass.
DoorsA great-value uPVC door with multi-point locking, a lead-free frame and A-rated glazing. They work as front doors, back doors or side doors.
DoorsBoth doors open fully to the garden. It's a classic look with modern locking, and you can match it to your windows.
SlidingMASTERslide patio doors have 12-point locking, a two-part security interlock and an aluminium low-threshold option for step-free access.
FoldingThe panels glide on a Teflon track and fold flat against the master door, with no visible hinges or handles. They open a whole wall to the garden.
AluminiumAluK aluminium bi-folds open a whole wall to the garden, with slim frames and a low threshold.
AluminiumFront doors, French doors, pivot doors and steel-look doors in slim AluK aluminium, in any powder-coated colour.
Slim AluK aluminium frames give you more glass and less frame. Casement and fixed styles in any powder-coated colour, with a different colour inside if you like. A strong, modern choice for new builds, extensions and refurbishments.
CommercialAluminium shop fronts with a commercial entrance door, side screens and a fanlight, made to fit your unit.
RoofsAluminium roof lanterns for flat roofs, orangeries and extensions. They fill the room below with daylight.
ConservatoriesADVANCE 70 conservatories and orangeries are designed to be used all year round. We design, supply and build them for you, start to finish.
Holiday homesReplacement windows and doors for static caravans and lodges, sized for park homes, for parks and owners across Wales.
There are 19 finishes, from smooth Ulti-Matt Black to wood-grain oaks. You can have one colour outside and white inside, or the same on both sides. Tap a colour to try it.
The chambers trap air to cut heat loss, and the frames are 100% lead-free.
We use proven high-security locking hardware, with certified options on every range.
Choose 24mm, 28mm or 40mm units, to keep you cooler in summer and warmer in winter.
RTR (Recycled Thermal Reinforcement) bar boosts the insulation without adding steel cold-bridges.
They keep the weather out, with no draughts and no leaks.
IB Windows is a member of the Installsure Insurance Backed Guarantee scheme, in compliance with FENSA. When we finish an installation, you automatically get an insurance-backed guarantee, so your cover is protected even if the company that fitted it is no longer trading.
Installsure membership no. 22897, since 11 August 2026. Terms and conditions apply.
View the certificate →
Our own designer lets you build every window and door in the house. Pick from over 200 styles, chamfered or sculptured frames, colours inside and out, glass, handles and locks. Turn it in 3D, see it from inside, and try it on a photo of your house. Got measurements? It checks them the way a surveyor does. No measurements? Design away and we'll measure for free.
BeforeAfter
Take a photo of your house and drop your new windows and doors straight onto it. Drag the corners to fit, switch between inside and outside photos, then download the picture or send it to a friend. Your photos stay on your phone or computer.
IB Windows works from Sloper Road in Cardiff, alongside our sister companies.
An independent builders' merchant in Cardiff, for trade materials, timber and aggregates.
ibbuildingmerchants.comCan't see your question here? Call 02920 001 636.
In a flush sash window, the opening part sits level with the outer frame instead of sticking out past it. It looks like a traditional timber window but has uPVC's low maintenance and thermal performance. We offer a 70mm frame for a modern look or an 80mm frame for a more traditional one.
Yes. Every window, door and conservatory we supply comes with a 10-year manufacturer's guarantee, and our products are designed and made in Britain. When we fit them, you also get an insurance-backed guarantee through Installsure (membership no. 22897), in compliance with FENSA. It covers up to the value of your contract for up to 10 years. Terms and conditions apply.
Yes. Our aluminium windows, doors, bi-folds and shop fronts are made with AluK systems, in any powder-coated colour, and you can have a different colour inside. We also supply and fit aluminium roof lanterns.
Our windows and doors use tried-and-tested high-security locking. PAS 24 and Secured by Design certified options are available across the range, and patio doors come with 12-point locking.
We use A-rated glass, with double and triple glazing in 24mm, 28mm and 40mm units depending on the product. Frames are multi-chambered and 100% lead-free. RTR thermal reinforcement bar is available for better insulation.
Yes. There are 19 finishes, including Anthracite Grey, Ulti-Matt Black, Chartwell Green, Cream, White Woodgrain and several wood-grain oaks. You can have a colour on one side or both.
Yes. Our Virtual Home tool lets you upload photos of your house, drop the windows and doors you designed onto them, and drag the corners to fit. Your photos stay on your device. You can download the picture or send it to a friend.
Both are ADVANCE 70 profiles. Chamfered frames have crisp 45° bevelled edges for a clean, modern look. Sculptured frames have softer, rounded edges for a more traditional look. You can see both in the online designer.
You can design your windows and doors in our online designer and send us the list, call 02920 001 636, or book a free home appointment. You don't need measurements to use the designer: our surveyor measures every opening for free. Quotes are free and carry no obligation.
Tell us what you're after and we'll arrange a free survey anywhere in Cardiff or South Wales. You'll get a fixed written price, with no hard sell.
