PVC windows made sense to a lot of London homeowners in the 1990s and early 2000s. They were affordable, low-maintenance, and widely available. But decades on, many of those same homeowners are staring at warped frames, fogged-up double glazing, and a kerb appeal that works against them every time a buyer walks up the path. The cost of staying with PVC, it turns out, is not as low as it once seemed.
The shift toward quality timber joinery is not just an aesthetic one. Homeowners who invest in timber sash windows are increasingly doing so with a clear financial rationale: better insulation, longer product lifespan, reduced maintenance cycles over time, and a measurable uplift in property value. These are not abstract benefits. They are the kind of outcomes that show up in estate agent valuations and energy performance certificates.
What PVC Actually Costs Over Time
The initial price of a PVC window is lower than timber, and that is the comparison most people stop at. But PVC has a functional lifespan of roughly 20 to 25 years before it begins to degrade visibly and structurally. Seals fail. Profiles discolour. The material cannot be repaired the way timber can; it has to be replaced wholesale.
Timber, when properly specified and finished, performs for significantly longer. Accoya, for instance, is an acetylated softwood with a guaranteed lifespan of 50 years above ground, backed by documented dimensional stability that prevents the warping and swelling common in lesser timber choices. The mathematics of replacing PVC twice in the time a quality timber window lasts once begins to look rather different when laid out that way.
Energy Performance: Where the Numbers Get Interesting
Modern timber windows, fitted with double glazing and precision draught-proofing, perform exceptionally well against current energy efficiency standards. The thermal performance of a well-constructed timber frame is competitive with, and in some cases superior to, mid-range PVC, largely because wood is a natural insulator. Air leakage is the real enemy of energy efficiency in older windows, and bespoke joinery fitted to exact tolerances eliminates the gaps that older installed units develop over time.
For London homeowners on higher energy tariffs, the reduction in heat loss through properly fitted windows translates into meaningful annual savings. Combined with the fact that well-maintained timber windows rarely need full replacement within their lifespan, the cost-per-year calculation shifts substantially in timber’s favour.
Property Value and Period Homes
This is where the financial case becomes particularly compelling for London’s Victorian, Edwardian, and Georgian housing stock. Period properties with original or sympathetically matched timber windows consistently attract stronger valuations than equivalent homes with PVC replacements. Buyers who understand period architecture, and there are many in London’s competitive market, actively discount properties where the windows undermine the character of the building.
In conservation areas, the argument is not simply about preference. Planning guidance in many London boroughs requires like-for-like replacement of original timber joinery, meaning PVC is not a legitimate long-term option regardless of personal preference. Choosing quality timber from the outset avoids the cost and disruption of a forced upgrade later.
Craftsmanship as a Financial Asset
There is a version of this decision that is purely numerical, and then there is the fuller picture. Bespoke timber joinery, hand-crafted to the specific dimensions and architectural style of a property, does not depreciate in the way off-the-shelf materials do. It becomes part of the fabric of the building.
With over 30 years of experience designing, manufacturing, and installing timber windows and doors across London, the team at Todi & Boys understands how to specify products that hold their value. Every window leaves the Chessington workshop built to exact tolerances, finished to a standard that protects the timber for decades, and installed with the kind of care that ensures performance from day one.
The upfront investment is higher than PVC. The long-term return, measured in energy savings, avoided replacement costs, and property valuation, tells a different story entirely.
Jen is an award winning digital publisher and has been creating interiors and home decor content for over 10 years.
She has an insatiable love of home interiors, has worked with hundreds of brands, and currently supports many bloggers within the creative industries to share their expertise through writing.
She spends most of her time in her little garden office pod, has 2 daughters and 2 (fighting) cats.
