How to choose the right timber for period accurate windows

Restoring and replicating period windows is something that requires layers of consideration based on a number of factors. For heritage homeowners, conservation officers, and architects, selecting the correct timber is a critical step that influences both the longevity and authenticity of a restoration. At Sutherland Joinery, we specialise in crafting and restoring timber windows that respect historical details while standing the test of time.

Here’s what to consider when choosing the right wood for your period window project.

1. Considering the Original Material

When restoring listed or heritage properties, it’s essential to maintain the architectural integrity of the building. This sometimes means using the same or a similar species of timber as the original. Common historical choices include:

• Pitch Pine: Frequently used in 18th and 19th-century windows for its availability and ease of working.

• Oak: Found in older, high-status buildings; prized for its strength and traditional character.

• Douglas Fir: Valued for stability and relatively straight grain; a common replacement in conservation work.

Some timbers will have been easier to source of a certain quality a century or two ago, and with our modern globalisation some timbers from across the globe have become more available than what were common native species in the 19th century. We also now have available to us a variety of modern modified timbers. So although looking at existing materials used is a good starting point, it isn’t always the best thing to use for a replacement window.

If you're unsure of the original material we can identify it and suggest the best match.

2. Durability and Resistance to Weather

Timber windows, especially in the UK’s damp climate, need to resist rot and movement over time. Hardwoods generally outperform softwoods in terms of longevity, but treatment, paint finishes, and proper joinery also play vital roles.

• Accoya (modified softwood) is a modern, sustainable choice that is essentially a pine that has undergone a chemical process to increase its durability and stability. It is easy to work with and is incredibly durable (comparable to oak).

• Sapele or Utile (hardwoods) are often used in restoration projects for their durability and fine finish, while still being sympathetic to original features.

3. Workability and Finish

Restoration requires precise detail to match mouldings, glazing bars, and profiles. The timber you choose should take a fine finish, hold paint well, and be easy to work with for traditional joinery techniques.

• Utile and Accoya are ideal in this regard, allowing for crisp mouldings and take paint well.

• Oak offers a rich traditional finish but is more challenging to work due to its hardness, generally we only suggest oak if leaving untreated or if using a clear finish and desire oak for aesthetic or legacy reasons

4. Sustainability and Sourcing

With growing environmental concerns, responsibly sourced timber is more important than ever. All the wood we use is  FSC or PEFC certified, and sourced from sustainable forests, or is sourced from a local sawmill where they use trees that had to be cut down for reasons other than producing timber.

We can provide documentation on our timber and its origins for listed building consent or conservation area requirements.

5. Cost vs. Longevity

While hardwoods and engineered timbers may come at a premium, their superior performance and reduced maintenance can save money over time. For many restorations, Accoya offers the best balance of performance, and longevity, especially when paired with high-quality paint and glazing sealants.

Final Thoughts

Every period property is unique—and so is every window. Choosing the right timber requires a balance of historical sensitivity, material performance, and future-proofing. At Sutherland Joinery, we combine years of experience in heritage joinery with a deep respect for traditional materials and methods.

Need advice on your own restoration project?
Contact us today to discuss timber options, arrange a site visit, or request a detailed quote.