Target Audience: Discerning homeowners looking for high-quality, sustainable, and extremely long-lasting timber windows, who might be concerned about traditional wood maintenance.
Why Golden Ratio Chooses Accoya Windows
At Golden Ratio Sash Windows & Doors, we believe your home deserves more than just a window; it deserves a masterpiece of engineering and heritage. That is why we specialize exclusively in timber and Accoya. While traditional wood has its charms, we have moved beyond the limitations of the past to offer our customers the “Golden Ratio” of beauty, sustainability, and lifelong performance.
Our Accoya windows are so durable they come with an industry-leading 50-year above-ground warranty, giving you total peace of mind for decades to come.”
The Secret to Stability: Our Accoya Standard
We use Accoya modified timber as standard in our Signature Range because it represents a scientific leap in what timber can achieve. Through a unique process called acetylation, the timber is modified to prevent it from absorbing water.

Unlike traditional timber, Accoya is scientifically proven to be more dimensionally stable. You can read more about the performance testing here to see how it outperforms even the best tropical hardwoods.
- No More Warping: Say goodbye to the swelling and distortion that often affects traditional wood products.
- Smooth Operation: Because the wood is so stable, your sash or casement windows will open and close perfectly through every season.
- Longer-Lasting Finish: Accoya’s stability means paint coatings stay intact for significantly longer, reducing your maintenance schedule.
Hand-Crafted Excellence Every window and door from Golden Ratio is the result of decades of joinery expertise. Our products are:
- British Made: Designed, manufactured, and finished by time-served joiners who treat every frame with the care it deserves.
- Durability You Can Trust: Accoya offers a 50-year service life (above ground), making it a far superior investment compared to uPVC or aluminum alternatives.
- Sustainable by Design: Sourced from fast-growing, responsibly managed forests, our timber is the greenest choice for the environmentally conscious homeowner.

Here are the specific styles of Accoya windows available:
1. Flush Windows

- Design: These windows are designed so the sash sits level (flush) with the external face of the window frame when closed, creating a clean and timeless aesthetic.
- Suitability: This style is often favored for both traditional cottages and contemporary minimalist homes due to its sleek, understated lines.
- Technical Excellence: Because they are crafted from Accoya, the flush fit remains precise year-round without the wood expanding and causing the sash to stick.
2. Stormproof Windows

- Design: Unlike the flush style, stormproof window sashes “overlap” the frame slightly when closed.
- Performance: This design provides an extra level of protection against the elements, as the overlap acts as a natural rebated seal against wind and heavy rain.
- Durability: Utilizing Accoya ensures these high-exposure windows maintain their structural integrity and energy efficiency even in Britain’s most challenging weather.
3. Sash Windows

- Design: A classic British staple, these windows consist of one or more movable panels (sashes) that slide vertically.
- Heritage & Innovation: While the style is traditional, the use of Accoya timber solves the historical issues of sliding sashes sticking or rattling due to moisture absorption.
- Craftsmanship: Each sash window is hand-finished by time-served joiners to ensure the smooth, effortless operation required for this iconic style.
Key Benefits for All Styles
Regardless of the style you choose, all Accoya windows from the Signature Range offer:
- 50-Year Service Life: Highly resistant to rot and decay.
- Sustainability: Sourced from fast-growing, responsibly managed forests.
- Low Maintenance: The dimensional stability of the wood means paint and translucent coatings last significantly longer.
Conclusion Don’t settle for the compromise of plastic. Experience the warmth of genuine timber and the peace of mind that comes with Accoya technology. Visit our workshop to see our team in action and experience the Golden Ratio difference first-hand.