Oak vs Accoya vs Red Grandis: Choosing the Best Timber for Window Manufacturing

At Morgan Bespoke Joinery, we understand that choosing the right timber for your custom windows is crucial for both aesthetics and performance. In this guide, we'll compare three popular wood options - oak, Accoya, and red grandis - to help you make an informed decision for your timber window manufacturing project.

Oak: Traditional Elegance and Strength

Oak has been a popular choice for window manufacturing for centuries, and for good reason:

  • Durability: Oak is naturally resistant to decay and insects.

  • Aesthetics: It offers a classic, timeless appearance with a distinctive grain pattern.

  • Strength: Oak is known for its excellent structural properties.

However, oak does have some considerations:

  • Maintenance: Requires regular upkeep to prevent weathering and maintain its appearance.

  • Weight: Heavier than some alternatives, which can affect installation and operation.

  • Cost: Generally more expensive than some other timber options.

Accoya: The High-Performance Modern Option

Accoya has gained popularity in recent years due to its exceptional properties:

  • Durability: Offers unparalleled resistance to decay and insects, with a 50-year above-ground warranty.

  • Stability: Extremely resistant to swelling and shrinkage, maintaining a precise fit.

  • Low Maintenance: Requires minimal upkeep, saving time and money in the long run.

  • Sustainability: Made from fast-growing, sustainably sourced wood species.

Considerations for Accoya:

  • Cost: Initially more expensive than traditional timbers, but can be cost-effective long-term due to low maintenance.

  • Appearance: While it can be painted or stained, it lacks the natural grain patterns of hardwoods like oak.

Red Grandis: The Balanced Choice

Red Grandis offers a middle ground between traditional hardwoods and high-tech options:

  • Durability: Similar in strength to oak, with good resistance to decay and insects.

  • Workability: Machines well, making it ideal for detailed joinery work.

  • Aesthetics: Offers a pleasing grain pattern and takes finishes well.

  • Sustainability: Grown in managed plantations, making it an eco-friendly choice.

Considerations for Red Grandis:

  • Lesser-Known: Not as widely recognized as oak or Accoya.

  • Maintenance: Requires more upkeep than Accoya but less than oak.

Comparing Performance in Window Manufacturing

When it comes to window manufacturing, each timber type has its strengths:

  1. Dimensional Stability:

    • Accoya leads the pack with exceptional resistance to warping and swelling.

    • Red Grandis offers good stability, particularly in comparison to oak.

    • Oak, while durable, may require more careful design to account for natural movement.

  2. Longevity:

    • Accoya boasts the longest lifespan, with a 50-year warranty against rot and decay.

    • Oak has proven its longevity over centuries but requires proper maintenance.

    • Red Grandis offers good longevity when properly maintained, comparable to other hardwoods.

  3. Thermal Performance:

    • All three woods provide good insulation properties.

    • Accoya's stability allows for tighter seals, potentially improving overall window energy efficiency.

  4. Environmental Impact:

    • Accoya and Red Grandis are sourced from managed plantations, offering strong sustainability credentials.

    • Oak, while renewable, grows more slowly and may have a higher environmental impact.

Making the Right Choice for Your Windows

When selecting timber for your window manufacturing project, consider:

  1. Climate: In areas with high humidity or temperature fluctuations, Accoya's stability shines.

  2. Maintenance Preferences: If low maintenance is a priority, Accoya is the clear winner.

  3. Aesthetics: For a traditional look, oak or red grandis might be preferable.

  4. Budget: Balance initial costs with long-term maintenance expenses.

  5. Environmental Concerns: All three options can be sustainable choices when sourced responsibly.


At Morgan Bespoke Joinery, we offer all three timber options - oak, Accoya, and red grandis - for our custom window manufacturing. Each wood type has its unique benefits, and the best choice depends on your specific needs, preferences, and project requirements. Our expert team is here to guide you through the selection process, ensuring you get the perfect windows for your home or commercial property.

Ready to start your custom timber window project? Contact Morgan Bespoke Joinery today for a consultation. Let us help you choose the perfect wood for your bespoke windows, combining traditional craftsmanship with modern performance.