Timber and Wooden Windows Installation and Replacement Cost Calculator

How this calculator works

This calculator estimates a realistic price range rather than a single figure, because real-world quotes genuinely vary that much. It starts from typical UK supplied-and-fitted price ranges drawn from published 2026 industry cost guides, then multiplies them by the number of units you enter and by adjustment factors for each choice you make below. The result is a low-to-high band that a fair quote is likely to fall within, not a promise of the exact price you will pay.

Timber casement windows typically cost around to supplied and fitted in 2026, with timber sash windows starting around and rising well beyond for hardwood heritage designs. Timber costs roughly twice as much as uPVC upfront, but well maintained wooden windows can last 30 to 60 years, considerably longer than uPVC.

Number of timber windows

Enter how many timber windows you want installed or replaced. On period properties it is common to replace street-facing windows in timber to satisfy planning requirements while using cheaper materials at the rear, so you may want to run the calculator separately for each elevation.

Window size

Size is one of the biggest cost drivers for any glazed unit. A larger opening needs more frame material and a bigger, heavier sealed glass unit, and it usually takes longer to fit. The calculator uses three broad size bands based on common UK window dimensions: choosing the small band reduces the typical range by around 20 percent, while the large band increases it by around 40 percent. If your windows vary in size, run the calculator once per size band and add the results together.

Timber type

Softwood, usually redwood or similar, is the entry point for timber windows and takes paint well but needs the most maintenance. Hardwoods such as oak or sapele cost roughly 50 percent more and last longer with better dimensional stability. Engineered timber, built up from laminated layers, resists warping better than solid wood and has become the standard for quality joinery, typically sitting between softwood and hardwood on price.

Specification level

Two windows that look similar from the street can sit at very different price points. Budget products use simpler profiles, standard hardware and basic glass. Mid-range covers the typical A-rated units most UK installers quote by default. Premium covers high-end systems with upgraded security hardware, better thermal performance, special finishes or designer profiles, and typically adds around 30 percent to the price.

Where you live

Labour rates are not uniform across the UK. Published cost guides consistently show installation prices in London and the South East running roughly 20 to 30 percent above the national average, driven by higher labour costs, travel, parking and congestion charges. The calculator applies an uplift of around 20 percent if you select London and the South East. Product prices themselves are broadly similar nationwide, so the difference mostly reflects fitting costs.

What else affects the price

Maintenance is the honest cost of timber: frames want repainting or restaining every five to eight years, sooner on south-facing and exposed elevations, and skipping it dramatically shortens their life. On the other side of the ledger, timber is the only material accepted for many listed buildings, and conservation area policies frequently require it on visible elevations, where replacing original windows without the right consent can lead to enforcement action. Factory-finished paint systems, dual colour finishes and authentic details such as putty-line glazing bars all add to the price but improve longevity and kerb appeal.

Planning permission, building regulations and certification

Like-for-like window replacement on most houses does not need planning permission, but listed buildings always require consent and conservation areas often restrict materials and styles on visible elevations, so check with your local planning authority if either applies. Building regulations apply to every replacement window in a dwelling, setting minimum energy performance and safety glazing standards. Installers registered with a competent person scheme, such as FENSA or Certass, can self-certify compliance and issue a certificate after completion; otherwise you must arrange building control sign-off separately. Keep the certificate safe, as buyers’ solicitors routinely ask for it when you sell.