Timber Windows vs uPVC Windows: A Contractor’s Insight

Choosing between timber windows vs uPVC windows is one of the most common decisions contractors help clients make. Both have their place. Both have their own set of advantages. But the right choice depends on the project.

This guide breaks down the real differences between timber and uPVC window frame materials, covering lifespan, maintenance, thermal performance, aesthetics and planning considerations. We’ll also look at how modern engineered timbers like Accoya wood have closed the maintenance gap that used to make uPVC the automatic default.

Timber vs uPVC windows: a quick rundown

uPVC frames are a more affordable option upfront and need minimal maintenance, making them a popular choice for budget-conscious new builds. Timber windows offer better aesthetic appeal, natural thermal insulation and are often the only option for conservation areas and period properties. Modern timber, especially Accoya wood, now matches uPVC for low maintenance while outperforming it on looks, longevity and environmental credentials.

What’s the difference between timber and uPVC windows?

uPVC stands for unplasticised polyvinyl chloride. It’s a rigid plastic that’s moulded into window frame shapes, then fitted with double glazing or triple glazing units.

Timber windows are made from solid wood, either softwood, hardwood, or engineered options like Accoya. They’re built using traditional joinery techniques, often combined with modern draught-proofing and glazing technology.

Both materials can deliver good insulation and energy efficiency. But the way they achieve this, and how they perform over time, differs significantly.

Lifespan: how long do they actually last?

This is where the comparison gets interesting.

uPVC windows: Typically last 20 to 30 years. UV exposure causes the plastic to discolour and become brittle over time, often requiring full replacement rather than repair.
Standard timber windows: With proper maintenance, can last 30 to 60 years.
Accoya timber windows: Carry a 50-year above-ground warranty, with a tested lifespan that can exceed 60 years, even in exposed or coastal locations.

For contractors working on new builds or renovations where longevity matters, timber frames, particularly Accoya, offer a clear advantage over the long run.

Maintenance: is timber really harder work?

This is the biggest objection contractors hear from clients considering timber windows.

It’s true that older softwood windows needed regular maintenance, including repainting every few years to prevent rot. This is where uPVC built its reputation for easy maintenance.

But modern timber windows have moved on. Here’s why:

Factory-applied finishes last far longer than traditional site-applied paint.
Accoya wood barely swells or shrinks, so coatings don’t crack or peel as quickly.
Improved draught-proofing reduces the strain on frames from weather exposure.

With proper care, modern timber windows need a simple check and occasional touch-up, not a full repaint every two years. Accoya in particular needs minimal maintenance compared with standard softwood, closing much of the gap with uPVC.

uPVC still has a practical edge for clients who want to do absolutely nothing. It doesn’t need painting at all. But it’s worth noting that uPVC frames can’t be repaired if damaged. Timber can be sanded, patched and refinished, extending its life rather than ending it.

Thermal performance and energy efficiency

Both materials can achieve excellent energy efficiency when paired with modern double glazing or triple glazing.

However, wood is a naturally insulating material. Timber has natural thermal insulation properties that plastic simply doesn’t replicate in the same way. This is one reason period properties with original timber frames often retain heat well once draught-proofed and upgraded with modern glazing.

Accoya specifically has been tested with thermal conductivity figures that are:

8% better than standard softwood
30% better than hardwood

This directly affects energy bills. Better insulation means less heat loss, which means lower energy costs for homeowners over the long term. For contractors advising clients focused on reducing their carbon footprint and energy costs, timber is often the stronger recommendation.

Aesthetic appeal: does it matter for the project?

For many projects, visual appeal is a significant factor, not just a nice-to-have.

uPVC has improved considerably. Modern uPVC windows come in a wider range of colours and finishes than the plain white frames of 20 years ago.

But timber still offers something uPVC can’t fully replicate: the natural grain, texture and character of a genuine wood window. For period homes, listed buildings and properties in conservation areas, the appearance of timber isn’t just preferred, it’s often required.

Timber also supports styles that are harder to achieve in plastic, including:

Flush sash windows and sliding sash windows
Timber casement windows
Bay and bow windows
Matching bifold doors for a consistent look throughout a property

Conservation areas and period properties

This is where the decision often gets made for you, not by preference, but by planning rules.

Many conservation areas and listed buildings require like-for-like replacement. That means timber frames must replace timber frames. uPVC alternatives are frequently refused planning permission in these settings because the material doesn’t match the original window frame materials or appearance.

For contractors working on heritage projects, specifying timber from the outset avoids delays, planning objections and costly redesigns later.

Environmental impact and sustainability

Timber is a renewable resource. Responsibly sourced wood, including FSC-certified Accoya, has a lower environmental impact than uPVC, which is a plastic product derived from fossil fuels and difficult to recycle at end of life.

For clients who want an environmentally friendly choice, timber windows, particularly those made from sustainably sourced Accoya wood, offer stronger environmental credentials than standard uPVC frames.

Making the right choice for your project

There’s no single best material for every project. The right choice depends on:

Budget: uPVC is typically the more affordable option upfront
Property type: Period properties and conservation areas usually require timber
Longevity: Accoya timber offers a longer lifespan with less long-term cost
Appearance: Timber offers greater visual appeal and design flexibility
Maintenance expectations: Modern timber finishes have closed much of the gap with uPVC

Frequently asked questions

Is timber or uPVC better for energy efficiency?

Both can achieve excellent energy efficiency with modern glazing. Timber has natural insulating properties that give it a slight edge, particularly with Accoya wood.

Do uPVC windows last as long as timber?

No. Standard uPVC windows typically last 20 to 30 years, while well-maintained timber windows, especially Accoya, can last 50 to 60 years or more.

Can I install uPVC windows in a conservation area?

Usually not. Most conservation areas require timber window frames to preserve the original character of the property.

Is Accoya a good alternative to standard timber?

Yes. Accoya offers the appearance and natural material benefits of timber, with significantly reduced maintenance and improved durability compared with standard softwood.

Helping you make an informed decision: contact our expert team today

Specifying the right windows is a significant investment, for contractors and homeowners alike. GB Joinery manufactures a full range of timber windows, including sliding sash, flush casement and stormproof designs, built to order in 4 to 6 weeks.

Whether you’re working on a new build, a period property restoration, or a project in a conservation area, we can help you specify the right windows for the job.

Get in touch with GB Joinery for a free trade quote or to discuss your next project: