Specify Timber with Confidence
Accoya® gives architects the freedom to design with natural timber while addressing many of the performance challenges traditionally associated with wood. Its exceptional dimensional stability, durability and resistance to rot make it particularly suited to demanding exterior applications — from windows and doors to cladding, decking, screens, pergolas and large-format architectural joinery.
Backed by extensive independent testing, internationally recognised environmental credentials and an industry-leading warranty, Accoya allows timber to be specified with greater confidence across residential, commercial and hospitality projects.
Performance That Expands What's Possible with Timber
Accoya® combines the natural character and workability of real timber with exceptional dimensional stability and durability, giving architects greater freedom to specify timber in demanding exterior applications.
Exceptional Dimensional Stability
Movement is one of the key considerations when specifying exterior timber. Accoya’s acetylation process significantly reduces its ability to absorb water, resulting in approximately 80% less swelling and shrinkage than untreated wood.
For architects, this translates into greater freedom to design wider boards, large-format doors and windows, finer sections and precision joinery, with significantly reduced movement as environmental conditions change.
Built for Exterior Environments
Accoya is Durability Class 1 and engineered for demanding exterior conditions, including exposure to moisture, changing humidity, coastal environments and long-term weathering.
This makes Accoya particularly valuable where longevity, dimensional accuracy and reduced maintenance are critical to the specification.
- 50-Year Warranty — Above Ground
- 25-Year Warranty — In Ground or Fresh Water
Greater Freedom in Design
Accoya can be cut, machined, profiled, glued and finished using conventional woodworking techniques, allowing it to be adapted to both traditional joinery and highly contemporary architectural detailing.
Its stability also allows architects to work with thinner sections, wider profiles and larger-scale timber elements than may be practical with less stable species.
Accoya can be left natural to weather, stained to retain the appearance of timber or coated in virtually any colour to suit the architectural palette.
Better Coating Performance
Reduced swelling and shrinkage places significantly less stress on coatings and joints. This can extend coating performance and reduce maintenance requirements over the life of the building — particularly valuable for windows, doors, cladding and difficult-to-access exterior elements.
Designed for Long-Term Specification
FSC® Certified
Manufactured using timber sourced from FSC® certified forests.
Cradle to Cradle Certified® Gold and Platinum for Material Health
Accoya® is Cradle to Cradle Certified® Gold overall and has achieved Platinum – the highest possible level – for Material Health. Accoya is recognised as the only construction material in the world to achieve this combination, demonstrating the exceptional material health and environmental credentials behind its specification.
Durability Class 1
The highest durability classification for timber against fungal decay.
50-Year Warranty
50 years above ground, with a 25-year warranty in ground and fresh water.
Exceptional Dimensional Stability
Approximately 80% less swelling and shrinkage than untreated wood.
Non-Toxic Modification
Acetylation modifies the wood without introducing toxic wood preservatives.
One Timber. Multiple Applications.
Accoya can be specified across multiple architectural elements, allowing a consistent timber language to be carried throughout a project while adapting sections and profiles to the performance requirements of each application.
Windows & Doors
Exceptional dimensional stability makes Accoya particularly suited to casement and sliding sash windows, entrance doors, sliding and folding systems and large-format architectural joinery.
Reduced movement helps maintain tolerances, alignment and smooth operation — particularly important for oversized doors and expansive glazed openings where timber stability becomes critical.
Cladding
Accoya’s stability allows for narrow or wide boards, precision profiles and refined sections, with cladding profiles capable of being machined down to approximately 8 mm, depending on profile and design requirements.
Reduced movement helps maintain consistent joints and clean architectural lines, while allowing the timber to be coated, stained or left to weather naturally.
Decking
Accoya provides a highly durable and dimensionally stable decking surface with reduced movement and excellent barefoot comfort.
Its stability allows decking to be machined down to approximately 15 mm, depending on profile, span and fixing requirements, enabling more efficient use of timber and providing architects with greater flexibility in finished floor levels and detailing.
Accoya’s stability also makes wider decking boards more practical than with many conventional timber species.
Screens, Fins & Pergolas
Stable and highly workable, Accoya is suited to architectural screens, fins, shutters, pergolas and exterior shading elements, where repeated sections and consistent alignment are important to the architectural expression.
Bespoke Architectural Joinery
From statement entrance and garage doors to gates, exterior ceilings and purpose-made architectural elements, Accoya provides the stability and machinability required for complex timber detailing and bespoke fabrication.
Technical Downloads
- Accoya Specification Guide V1.0[PDF]
- Accoya Technical Weathering Guide[PDF]
- Slip Resistance — Technical Leaflet[PDF]
- Fire Classification Report — Accoya FRX Euro B[PDF]
- Construction Drawings — Accoya Decking (EU)[PDF]
- Construction Drawings — Accoya Cladding on Timber Frame (UK)[PDF]
- Construction Drawings — Accoya Cladding on Masonry (UK)[PDF]
- Accoya Siding Specification[PDF]
- Decking Technical Datasheet[PDF]
- Windows & Doors Guide[PDF]
- Tricoya Panel Specifications[PDF]
Technical Support for Architects
Successful timber specification extends beyond species selection. Resolute Timbers works with architects from the early stages of a project to determine appropriate sections, profiles, finishes and manufacturing approaches for each application.
Backed by decades of practical timber joinery and manufacturing experience, our recommendations combine technical data with an understanding of how timber behaves once machined, assembled, finished and exposed in service.
Resolute Timbers can assist with:
Learn More About Modified Timber
We offer accredited CPD presentations for architectural practices looking to better understand modified timber technology and how products such as Accoya® and Tricoya® can be specified.
The session covers:
The presentation is designed to be practical and specification-focused, giving architects the technical knowledge needed to make informed material decisions.
Across Residential, Hospitality & Commercial Projects
Explore Accoya® across residential, hospitality and commercial projects throughout Southern Africa, including large-format windows and doors, decking, cladding and bespoke architectural joinery.
Planning a Project?
Let's Talk Timber. Whether you are at concept stage, developing a specification or working through detailed joinery requirements, our team can assist with samples, technical information and project-specific guidance.