10
Dec '25
Understanding U-values – What They Mean for Your Home
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SETTING A NEW STANDARD IN HERITAGE STYLE
Timeless Style, Modern Performance
SETTING A NEW STANDARD IN HERITAGE STYLE
Timeless Style, Modern Performance
The TimberLine difference
TimberLine – where traditional timber design meets modern innovation. Use the slider below to see how TimberLine delivers the perfect timber-style finish with advanced PVCu performance.
StyleLine weld
TimberLine weld
The TimberLine difference
TimberLine – where traditional timber design meets modern innovation. Behind the authentic timber-style finish sits a revolutionary construction that still allows for a traditional 45° welded joint. The result is the look of handcrafted timber, combined with the strength, consistency, and long-term performance installers expect from modern PVCu fabrication.
Use the slider below to see how TimberLine achieves a true timber appearance on the surface, without compromising on the proven welded construction beneath.
StyleLine weld
TimberLine weld
Why TimberLine?
Available only from Sternfenster, TimberLine windows and doors set a new benchmark for timber-look design and PVCu innovation.
TimberLine windows capture the authentic look of handcrafted timber joinery, while offering all the strength, efficiency, and low-maintenance benefits of modern PVCu – perfect for heritage homes and premium properties alike.
Every TimberLine window is precision-engineered and inspected at our UK manufacturing facility to ensure a flawless timber-style finish that enhances your home’s character and value.
Our advanced jointing method recreates the depth and definition of real timber, while the flush casement design delivers a sleek, heritage look that perfectly suits both classic and contemporary properties.
An innovative 45° welded joint gives TimberLine windows their distinctive timber appearance – stronger and more durable than mechanical joints, and with a cleaner, more authentic finish that stays looking great for years.
With multi-point locking, internal beading, and reinforced welded corners, TimberLine windows combine elegant design with exceptional strength and security, giving you complete peace of mind.
Why TimberLine?
Available only from Sternfenster, TimberLine windows and doors set a new benchmark for timber-look design and PVCu innovation.
We manufacture TimberLine windows with the authentic look of timber joinery, but with all the performance benefits of PVCu. TimberLine is the perfect upsell product for heritage, conservation, and premium projects.
Every TimberLine window is precision-engineered and quality-checked at our manufacturing facility to guarantee a flawless timber-look finish. We deliver nothing less than premium craftsmanship.
TimberLine windows use an advanced jointing method that replicates the deep, authentic look of timber – a feature today’s homeowners demand. With flush casement designs and heritage detailing, you can offer your customers a truly premium upgrade.
Using an innovative 45° welded joint, TimberLine recreates the appearance of traditional timber craftsmanship – no corner cleaning required. Because it’s fully welded, the joint is stronger and more durable than a mechanically jointed window, delivering a neater, more authentic finish every time.
Featuring multi-point shoot bolt locking, secure internal beading, and reinforced welded joints, TimberLine windows offer outstanding durability and peace of mind.
Unique Design
Authentic Timber Look, Modern Performance
Our innovative TimberLine manufacturing method recreates the deep, authentic look of traditional wooden windows.
Instead of standard PVCu welds, each joint mirrors the craftsmanship of heritage timber frames, giving you the timeless style you want combined with the durability of modern materials. With authentic timber-style joints, flush casement designs, and detailing ideal for heritage and conservation properties, TimberLine brings classic charm to any home.
Built to Last
Engineered for Strength & Security
TimberLine doesn’t just look stunning – it’s built to perform. Strong, secure, and energy efficient, these windows keep your home warmer, quieter, and safer.
Unlike real timber, PVCu won’t warp, rot, or peel, meaning you’ll enjoy lasting beauty with minimal maintenance. With A-rated energy efficiency, advanced security hardware, and a low-maintenance finish, TimberLine windows are designed to deliver lasting comfort and peace of mind.
Colour & Customisation
Styled for Every Home
Tailor your windows with heritage-inspired colours and authentic woodgrain finishes.
Choose from a wide range of woodgrain finishes and heritage colours to perfectly complement your property. From classic oak and rosewood to contemporary tones and sleek modern greys, TimberLine windows let you create the look you love – whether you’re restoring a period home or adding character to a modern build.
timberline
Unique Design
Authentic Timber Look, Modern Performance
With our advanced TimberLine manufacturing method, we’ve created a PVCu window that perfectly replicates the deep, authentic look of traditional timber joinery. Each 45° welded joint mirrors the craftsmanship of heritage wooden frames, delivering the timeless style homeowners want with all the strength and performance of modern materials.
Designed with authentic timber-style joints, flush casement detailing, and a premium finish ideal for heritage and conservation projects, TimberLine gives you a high-end product that’s easy to sell and built to impress.
Build your reputation and drive your sales with TimberLine windows – the perfect upsell for homeowners who want the look of timber, without the maintenance.
Built to Last
Engineered for Strength & Security
Every TimberLine window is precision-engineered and manufactured using the latest machinery at our Lincoln-based facility, ensuring exceptional quality and consistency across every frame. Our advanced welding technology creates strong, durable joints that outlast mechanically jointed alternatives, while maintaining a flawless timber-style appearance.
These windows stand apart from others thanks to the precision and innovation behind their manufacture – a difference your customers will notice the moment they see them. When you choose TimberLine, you’re choosing a product that elevates your business and sets you apart from the competition.
Colour & Customisation
Styled for Every Home
TimberLine windows and doors are available in a wide range of colours and woodgrain finishes to suit properties of every style – from traditional heritage homes to modern builds. This flexibility makes TimberLine an easy sell for installers, giving your customers exactly what they want with minimal effort.
Every TimberLine product meets rigorous quality and security standards, including British Standard Kitemark and Secured by Design accreditation. Give your customers total confidence in their investment with a product that’s as secure as it is stylish.
timberline
TimberLine profile options
Choose a flush sash profile for a truly authentic timber-style finish.
Designed to sit perfectly flush within the frame, it delivers clean sightlines, period-correct proportions, and the refined look customers expect from traditional timber windows.
FLUSH
TimberLine profile options
Choose a flush sash profile for a truly authentic timber-style finish.
Designed to sit perfectly flush within the frame, it delivers clean sightlines, period-correct proportions, and the refined look customers expect from traditional timber windows.
FLUSH
Transform Your Home's Look: Explore Our Window / Door Configurator -
Preview Our Extensive Range of Interior and Exterior Shades With The “Turn Around” Icon.
Single Colours
Our single colours are readily stocked and available with quick turnarounds.
White / White
White Grain / White Grain
Anthracite Grained / Anthracite Grained
Classic Cream / Classic Cream
Chartwell Green / Chartwell Green
Rosewood / Rosewood
Nut Tree / Nut Tree
Irish Oak / Irish Oak
Golden Oak / Golden Oak
Black Ash / Black Ash
Anthracite / Anthracite
Dual Colours
Enjoy interior and exterior customisation, as well as shorter delivery times with our stunning dual colour options.
Heritage Colours
Available for fast dispatch, our heritage colours offer shorter delivery times.
Premium Colours
Providing exceptional quality and individuality, our non stocked premium colour are available at an additional cost with extended lead times.
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White Grain / White Grain
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Grained / Anthracite Grained
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Classic Cream / Classic Cream
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Chartwell Green / Chartwell Green
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rosewood / Rosewood
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Nut Tree / Nut Tree
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Irish Oak / Irish Oak
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Golden Oak / Golden Oak
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / Black Ash
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite / Anthracite
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Irish Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Chartwell Green / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rosewood / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Nut Tree / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Golden Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Grained / White
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Grey Ali / White
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Smooth / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White Grain / White
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Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Classic Cream / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Smooth / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
English Oak / English Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
English Oak / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Heritage White / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Ice Cream / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Heritage White / English Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Ginger Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Dark Red / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Vin Rouge / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Fir Green / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Blue Steel / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Quartz Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Basalt Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Slate Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Cedar Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Claystone / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Honey Oak Super Matt / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Pepper Oak Super Matt / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Soft Cherry / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rustic Cherry / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Bronze Metallic / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Pyrite Metallic / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Silver Bullit / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Sage Smooth Matt / White PVC
TURN AROUND
Beautiful Colours
TimberLine windows truly stand out when finished in the right colour. Our durable, hard-wearing woodgrain foils and heritage shades are designed to retain their depth and vibrancy for years to come. Explore our collection of traditional and contemporary finishes to find the perfect match for every project.
Clear
Arctic
Autumn
Casin
Chantilly
Charcoal Sticks
Contora
Cotswold
Digital
Everglade
Flemish
Florielle
Mayflower
Minister
Oak
Pelerine
Reeded
Stippolyte
Sycamore
Taffeta
Tribal
Warwick
Glass Selected:
Clear
Bespoke Glazing
We offer a range of beautiful, bespoke glazing options. Made to measure and specialist designs are available, along with solar and privacy glass options.
Antique Black
Black
Brilliant Bronze
Gold
Chrome
Grey
Satin Chrome
Solid Gold
White
Antique Black
Black
Brilliant Bronze
Gold
Chrome
Grey
Satin Chrome
Solid Gold
White
Handles & Hardware
TimberLine windows are available with a range of high performance handles. Choose window handle colours to match the property style.
Transform Your Home's Look: Explore Our Window / Door Configurator -
Preview Our Extensive Range of Interior and Exterior Shades With The “Turn Around” Icon.
Single Colours
Our single colours are readily stocked and available with quick turnarounds.
White / White
White Grain / White Grain
Anthracite Grained / Anthracite Grained
Classic Cream / Classic Cream
Chartwell Green / Chartwell Green
Rosewood / Rosewood
Nut Tree / Nut Tree
Irish Oak / Irish Oak
Golden Oak / Golden Oak
Black Ash / Black Ash
Anthracite / Anthracite
Dual Colours
Enjoy interior and exterior customisation, as well as shorter delivery times with our stunning dual colour options.
Heritage Colours
Available for fast dispatch, our heritage colours offer shorter delivery times.
Premium Colours
Providing exceptional quality and individuality, our non stocked premium colour are available at an additional cost with extended lead times.
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White Grain / White Grain
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Grained / Anthracite Grained
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Classic Cream / Classic Cream
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Chartwell Green / Chartwell Green
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rosewood / Rosewood
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Nut Tree / Nut Tree
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Irish Oak / Irish Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Golden Oak / Golden Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / Black Ash
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite / Anthracite
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Irish Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Chartwell Green / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rosewood / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Nut Tree / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Golden Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Grained / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Grey Ali / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Smooth / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
White Grain / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Classic Cream / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite Smooth / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
English Oak / English Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
English Oak / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Heritage White / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Ice Cream / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Heritage White / English Oak
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Black Ash / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Anthracite / Heritage White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Ginger Oak / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Dark Red / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Vin Rouge / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Agate Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Fir Green / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Blue Steel / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Quartz Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Basalt Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Slate Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Cedar Grey / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Claystone / White
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Honey Oak Super Matt / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Pepper Oak Super Matt / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Soft Cherry / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Rustic Cherry / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Bronze Metallic / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Pyrite Metallic / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Silver Bullit / White PVC
TURN AROUND
Outside View
*Colour configurations are for illustration purposes only. For detailed colours, contact us today.
Frame Colour Selected:
Sage Smooth Matt / White PVC
TURN AROUND
Beautiful Colours
TimberLine windows truly stand out when finished in the right colour. Our durable, hard-wearing woodgrain foils and heritage shades are designed to retain their depth and vibrancy for years to come. Explore our collection of traditional and contemporary finishes to find the perfect match for every project.
Clear
Arctic
Autumn
Casin
Chantilly
Charcoal Sticks
Contora
Cotswold
Digital
Everglade
Flemish
Florielle
Mayflower
Minister
Oak
Pelerine
Reeded
Stippolyte
Sycamore
Taffeta
Tribal
Warwick
Glass Selected:
Clear
Bespoke Glazing
We offer a range of beautiful, bespoke glazing options. Made to measure and specialist designs are available, along with solar and privacy glass options.
Antique Black
Black
Brilliant Bronze
Gold
Chrome
Grey
Satin Chrome
Solid Gold
White
Antique Black
Black
Brilliant Bronze
Gold
Chrome
Grey
Satin Chrome
Solid Gold
White
Handles & Hardware
TimberLine windows are available with a range of high performance handles. Choose window handle colours to match the property style.
Click through our showroom to explore our products in greater detail
Explore Our Virtual Showroom
Click through our showroom to explore our products in greater detail
Explore Our Virtual Showroom
Steel Reinforcing And Internal Beading For Strength
Every TimberLine window is built with strength and security in mind. Hidden steel reinforcement inside the uPVC frame adds rigidity and durability, helping your windows stand strong against the elements year after year.
With internal beading and advanced multi-point locking as standard, TimberLine windows offer exceptional protection for your home. Optional claw locking provides added peace of mind, giving you confidence that your home is secure.
State-Of-The-Art-Machinery
TimberLine windows are crafted using cutting-edge manufacturing technology that recreates the look of handcrafted timber joints. Our innovative 45° welded design eliminates visible grooving, producing smooth, seamless corners that look just like real wood.
This advanced process not only creates a beautifully authentic finish but also ensures every frame is stronger and longer-lasting – giving you the timeless look of timber with all the benefits of modern engineering.
Steel Reinforcing And Internal Beading For Strength
Steel reinforcement, secure internal beading, and robust 45° welded joints make TimberLine windows exceptionally strong and durable. The reinforced uPVC frame enhances rigidity, providing superior resistance against weathering and everyday wear.
TimberLine windows are internally beaded and fully compliant with the latest European security standards, including BS7950 and PAS24. For added peace of mind, optional claw locking is available to deliver an extra layer of protection for your customers.
State-Of-The-Art-Machinery
TimberLine windows are produced using advanced machinery that eliminates the traditional grooving stage, creating a cleaner 45° welded joint that perfectly replicates the look of real timber joinery. The result is a stronger, neater, and more authentic finish straight from the factory.
Partner with Sternfenster to access this exclusive manufacturing technology. We deliver premium, timber-look windows at competitive trade prices – helping you stand out in the growing timber-alternative market.
Frequently Asked Questions
Do TimberLine products come with a guarantee?
Yes – every TimberLine window and door comes with a 10-year guarantee, including all woodgrain finishes. We’re confident in the quality of our materials and craftsmanship, ensuring your windows stay looking beautiful and performing perfectly for years to come.
How is TimberLine different from other PVCu windows?
TimberLine windows are designed to offer the beauty of real timber with all the benefits of modern PVCu. Using an advanced 45° welded joint, each frame recreates the authentic look of traditional wooden joinery – but without the maintenance, painting, or warping.
This innovative design gives every TimberLine window a smooth, seamless finish that’s stronger and more durable than mechanically jointed timber alternatives.
How energy efficient are TimberLine windows?
TimberLine windows don’t just look like timber – they perform better. With a Window Energy Rating (WER) of A as standard, they’re designed to keep your home warmer, quieter, and more comfortable.
Clever design features such as double weather seals, low sightline gaskets, and Super Spacer® bars maximise insulation and weatherproofing. You can even upgrade to triple glazing for ultimate energy efficiency and lower energy bills.
How is Sternfenster being sustainable?
We are committed to reducing carbon emissions in line with the government’s Net Zero target of 2050. Using sustainable materials such as uPVC, we’re able to recycle post consumer waste on a broad scale and contribute towards a circular economy.
Learn more about sustainability at Sternfenster here.
Why choose Sternfenster?
Based in Lincoln, Sternfenster is one of the UK’s leading window and door manufacturers, trusted by homeowners and installers nationwide. Our products – including TimberLine – combine innovative design, premium quality, and long-lasting performance.
We work with a network of approved local installers who share our commitment to exceptional service and attention to detail, ensuring your new windows are installed to the highest standards.
If you’d like to learn more about TimberLine or find a local installer, get in touch with our team today.
Frequently Asked Questions
How is TimberLine different from other PVCu windows?
TimberLine stands out for its authentic timber-look design and advanced 45° welded joints that replicate the craftsmanship of traditional wooden frames. This unique manufacturing process eliminates visible grooving, creating a cleaner, stronger, and more durable joint than mechanically joined alternatives. The result is a premium heritage-style window that’s easy to sell and built to perform.
Do TimberLine products come with a guarantee?
Yes – all TimberLine PVCu profiles, including woodgrain finishes, are covered by a 10-year guarantee. We take pride in the quality and durability of our materials, ensuring you and your customers receive lasting value and complete confidence in every installation.
Why choose Sternfenster?
Sternfenster is an award-winning, industry-leading manufacturer based in Lincoln, trusted nationwide for the quality of our products and service. We supply high-performance window and door systems – including TimberLine – to trade professionals across the UK, backed by reliable lead times, expert support, and competitive pricing.
Partner with Sternfenster and gain access to premium products, advanced manufacturing technology, and a network of trusted installers committed to excellence. Contact our team today to discuss TimberLine or any of our other trade solutions.
How energy efficient are TimberLine windows?
TimberLine windows don’t just look exceptional – they perform exceptionally too. With a Window Energy Rating (WER) of A as standard, they deliver superb thermal performance, helping homeowners reduce energy bills and improve comfort.
Features such as double weather seals, low sightline gaskets, and Super Spacer® bars enhance insulation and weatherproofing even further, with triple glazing available for maximum efficiency.
How is Sternfenster being sustainable?
We’re dedicated to reducing carbon emissions in line with the UK’s Net Zero 2050 target. Our PVCu products, including TimberLine, are manufactured using sustainable materials and processes that support large-scale recycling of post-consumer waste, contributing to a more circular economy.
Learn more about sustainability at Sternfenster here.
Energy Savings Calculator
Use our energy savings calculator to find out how much upgrading your windows can save you in the long run.
Energy Savings Calculator
Use our energy savings calculator to find out how much your customers can save in the long run.
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