
Redefining
the world of wood
Accoya is a revolution in modified dimensionally stable wood, delivering remarkable levels of performance. A product made to last.
Wood that changes the world
Accoya modified wood has become the benchmark in the timber industry for performance and sustainability. No other wood offers the same combination of durability, stability, and versatility. Sustainably sourced and with a low total lifetime carbon cost, Accoya actively contributes to a circular, bio-based economy and is one of the few truly sustainable building materials available.
In this video, we take a closer look at the groundbreaking science behind Accoya wood. Through a precise acetylation process using acetic anhydride—combined with carefully controlled heat and pressure—we increase the moisture-resistant acetyl groups and reduce the water-attracting hydroxyl groups. This unique, patented technology transforms fast-growing, sustainable wood into an ultra-high-performance building material.
Acetylation process
How it works
Hyrdoxyl Groups
Hydroxyls are hydrophilic (attract water), causing cellulose to swell (and shrink when subsequently dried) and become more susceptible to attach by biological organismsAcetyl Groups
Wood cellulose contains a small number of naturally occurring acetyl groups which are hydrophobic (repel water). There are an insufficient number of acetyls in natural wood to provide durable, stable performance.Acetylation
Reaction of wood with acetic anhydride (concentrated acetic acid) at high temperature to precisely increase the level of moisture resistant acetyl groups.Accoya Acetylated Wood
Contains the same constituents as natural wood, just at enhanced levels. There are now more of the moisture resistant groups and less of the moisture binding groups. This delivers high performance through increasing dimensional stability and enhanced biological durability.
Hyrdoxyl Groups
Hydroxyls are hydrophilic (attract water), causing cellulose to swell (and shrink when subsequently dried) and become more susceptible to attach by biological organismsAcetyl Groups
Wood cellulose contains a small number of naturally occurring acetyl groups which are hydrophobic (repel water). There are an insufficient number of acetyls in natural wood to provide durable, stable performance.Acetylation
Reaction of wood with acetic anhydride (concentrated acetic acid) at high temperature to precisely increase the level of moisture resistant acetyl groups.Accoya Acetylated Wood
Contains the same constituents as natural wood, just at enhanced levels. There are now more of the moisture resistant groups and less of the moisture binding groups. This delivers high performance through increasing dimensional stability and enhanced biological durability.
Outstanding
products to last a lifetime
Since its launch in 2007, hundreds of manufacturers have made Accoya their material of choice for windows, doors , decks , and cladding on homes and buildings. Accoya has also been used in some of the world’s most architecturally significant projects for its unbeatable performance and versatility.
Accoya is often used outdoors because of its strong properties of durability, dimensional stability, and resistance to rot. Accoya withstands all climates, and although it’s not completely waterproof, it’s highly resistant to moisture and humidity, which is why it’s often used near water.
Trade associations and professional bodies
We are active members of a number of trade associations and professional bodies supporting the industries we work in.

The British Woodworking Federation is the trade association for the woodworking and joinery manufacturing industry in the UK. Their focus is on Building it Better with Wood and promoting the inherent advantages of wood.

The timber decking and cladding association acts as a technical and advisory body for the UK timber decking and timber cladding industries. Assisting large commercial contractors and individuals undertaking their own projects they can advise on all areas including material selection and maintenance.

Wood knowledge Wales champion the development of wood-based industries for increased prosperity and well-being in Wales. They harness the collective spirit of businesses and organisations to put trees, timber processing and wood products at the heart of the green growth agenda in Wales.

Timber Development United Kingdom (TDUK) is the largest, most comprehensive supply chain body for timber in the UK. Every day they connect, inspire, and support more than 1,500 businesses to build a better world through wood.

The Wood Protection Association and its members champion the use of building with timber – influencing, developing and promoting technologies that enhance its performance and value as a building resource for the future.
Decade of Durability
where Accoya has been put to the test
Take a look at some Accoya projects from the last decade. These projects provide powerful evidence of Accoya’s extreme durability across both domestic and commercial applications. The results speak for themselves and demonstrate Accoya’s suitability for applications such as windows, doors, decking and cladding. Durability is just one factor in Accoya’s appeal to design experts and consumers alike. Find out more.




Where to Buy
You can buy Accoya and Accoya products from our selection of distributors or manufacturers in your region. Use our map search tool to find your nearest Accoya supplier.