We believe that it is our responsibility to look after our environment and the precious resources within it, which is why every piece of timber we use at Cotswood is FSC-certified. This means that it has been approved by the Forest Stewardship Council (FSC) as a sustainably sourced timber from a well-managed woodland. It also means that the people who work in the woodland are being treated fairly in their employment.


Accoya is a modified solid wood which performs even better than tropical hardwoods such as sapele or mahogany. It is plantation-grown in sustainably harvested woodlands. Once harvested, the timber goes through a modification process called acetylation. The wood reacts with acetic acid, changing its structure permanently. This is an environmentally friendly process – vinegar, after all, is just dilute acetic acid! After the reaction has taken place, moisture can no longer get in or out of the wood, meaning that it has become incredibly stable and durable – perfect for doors and doorframes.

We never use softwoods such as European Redwood, because this is unstable and would have to be treated with a toxic biocide to make it appropriately durable. We much prefer to pick high-quality timbers with excellent natural properties in terms of strength and durability.


Sapele is a traditional, close-grained hardwood, similar to mahogany in its rich reddish colour. Accoya is our premium timber, but we sometimes use FSC-certified sapele as an alternative for doorframes or doors if a customer is looking for a more economical option. We also occasionally use sapele for staining if a customer prefers its grain and appearance.

European Oak

We occasionally use FSC-certified European oak for doors because of its attractive wide grain. European oak is a durable timber, but it is also unstable, being prone to expansion, contraction and movement. A few of our customers still choose oak for their new door because they love the look of its distinctive, swooping grain. Wherever possible, though, we prefer to use Accoya, which is not only extremely stable and durable, but can also be stained to look beautiful.

Interior timbers

We usually construct painted interior doors from FSC-certified poplar. This is a stable, close-grained hardwood. It paints up like a dream and makes a good, solid interior door. We also make internal doors from oak, sapele, walnut and ash. Sometimes we use yellow pine, which is a special knotless pine species that is very stable.

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