Timber SashWindows London

Heritage & Planning

Conservation area windows

Timber windows for homes in conservation areas across London and the Home Counties — sympathetic to the character of the area, mindful of Article 4 directions and local planning policy, and matched to the windows already there.

A conservation area is designated to protect the special character and appearance of a place, not just individual buildings. Windows are one of the most visible parts of that character, so how you replace them matters — even when your own house is not individually listed.

In many conservation areas, ordinary permitted development rights still allow like-for-like window replacement. But where the council has made an Article 4 direction — which is common on the principal elevations of houses in conservation areas — those rights are removed, and planning permission is required before you change the windows. The first step on any project is simply knowing which rules apply to your property.

Whichever applies, the aim is the same: windows that preserve or enhance the character of the area. We match mouldings, glazing-bar widths, sightlines and proportions to the existing windows, in timber, so the replacements sit comfortably in the street scene while quietly improving comfort, draught-proofing and warmth.

Knowing whether an Article 4 direction applies to your home is the first step — and it is where every conservation-area project with us begins.

What matters

Designed around the rules for your home

Check for an Article 4 direction

Article 4 directions remove specific permitted development rights in a conservation area — most often for windows and doors on elevations facing a road. Where one applies, replacing your windows needs planning permission, even for like-for-like work. Your local planning authority can confirm whether your property is affected, and we help you approach them with the right drawings and specification.

Timber is usually expected

There is no blanket national ban on other materials, but in conservation areas councils commonly resist uPVC and expect timber windows that match the traditional appearance of the area. Timber is the natural choice for a sympathetic, policy-compliant replacement — and what we make.

Match the character of the area

We survey the existing windows and match their mouldings, glazing-bar widths, horns, meeting rails and sightlines — so the replacements read as authentic from the street. Where windows have already been altered unsympathetically, we can help return them to a form appropriate to the property's age.

Glazing that keeps the look

Our slim double-glazed and vacuum options, combined with 20mm timber-masked glazing bars, keep the classic period appearance while adding modern warmth and quiet — achieving whole-window U-values as low as 0.8 W/m²K. For the most sensitive settings, single glazing with solid true bars is also available.

If your building is also listed

Some homes are both in a conservation area and individually listed. In that case listed building consent applies as well, and the specification is scrutinised more closely. See our listed building windows page for how we approach those projects.

Specification

The detail, documented

Specification options for conservation area windows. Final specification is confirmed at survey and tailored to your property and conservation requirements.

Glazing options

Single glazed6mm toughened glazing with a solid through 'true bar' up to 24mm and putty-imitation external beads — for the most stringent heritage settings
Slim double glazed12mm unit (4–4–4, argon, low-E) giving a whole-window U-value of 1.9–2.2; or 14mm unit (4–6–4, argon, low-E) giving 1.6–1.8
Vacuum glazed7.8mm high-spec vacuum glazing giving a whole-window U-value of 0.8–1.0 — the slimmest sightline with the highest performance
Timber-masked glazing bars (20mm)Our most popular bar. Slim 20mm bars in matching timber, factory-finished with the window — ideal for Georgian, Victorian and Edwardian properties
True glazing bars (up to 24mm)Solid through 'true bars' up to 24mm wide (not stick-on), with putty-line finish
Leaded lightsTraditional leaded-light glazing in diamond or rectangular (square) patterns — ideal for period, heritage and conservation properties

Timber species

Engineered redwood pineWith hardwood sill — our most popular option, chosen for stability and value
Full hardwood merantiA durable hardwood throughout
Accoya®Modified timber with exceptional stability and longevity
European oakA premium, characterful hardwood
CertificationFSC® certified timber

Finish

Paint systemFactory spray-finished before delivery; microporous system that lets the timber breathe
ColoursSingle or dual colour, with a wide choice of RAL colours. We can also colour-match heritage brands such as Little Greene and Farrow & Ball
Coating warranty3 years on the factory-applied paint finish, subject to the recommended maintenance; recoating intervals depend on exposure and location

Guarantee

ComponentWarranty
Timber frame8 years
Glass & sealed units3 years
Hardware & ironmongery5 years
Paint finish3 years
ConditionsTimber and paint guarantees are subject to the recommended maintenance schedule. Guarantees cover manufacturing defects, not damage, neglect or normal wear.

How it works

From first survey to aftercare

  1. 01

    Initial quotation

    We provide an initial quotation within 1–3 days of your enquiry.

  2. 02

    Site survey

    Within 1–2 weeks we measure and document the openings on site, recording profiles, sightlines and any conservation status.

  3. 03

    Drawings & approval

    We produce production drawings and a specification for your approval — and to support any planning or listed building consent.

  4. 04

    Manufacture

    Once your specification is approved, each window is crafted to your approved specification. Typically 5–8 weeks; 7–12 weeks for larger or bespoke conservation work.

  5. 05

    Installation

    Our fitting teams install with minimal disruption — typically 1–5 days depending on project size.

Questions

Listed building windows: your questions answered

Do I need planning permission to replace windows in a conservation area?

It depends on your property. In many conservation areas, like-for-like replacement in the same material is still permitted development and does not need permission. But if the council has made an Article 4 direction — common on front and side elevations facing a road — those rights are removed and planning permission is required. We recommend checking with your local planning authority early. This is general guidance, not formal planning advice; your local authority makes the final decision.

What is an Article 4 direction?

It is a direction made by a local planning authority that removes certain permitted development rights in a defined area — often the right to alter windows and doors on the principal elevation of houses in a conservation area. Where one is in place, changes that would normally be automatic instead require a planning application. Your council can tell you whether your property is covered.

Can I use uPVC windows in a conservation area?

Often not, in practice. While there is no single national ban, conservation-area policies and Article 4 directions commonly require windows that preserve the traditional character of the area, and councils frequently resist uPVC. Timber windows that match the existing profiles are the sympathetic, low-risk choice — and are what we make.

Can I have double glazing in a conservation area?

Usually, yes. Our slim double-glazed units and high-spec vacuum glazing keep true glazing bars and traditional sightlines while achieving whole-window U-values as low as 0.8 W/m²K, so the appearance suits conservation requirements. Where an application is needed, we provide the drawings and specification to support it.

Which areas do you cover?

We work across London and the Home Counties, including Surrey, Kent, Essex, Hertfordshire and Buckinghamshire. If your property is in a conservation area or listed, we are happy to discuss it.

Discuss your project

Tell us about your property and we’ll advise on the most appropriate, consent-ready specification.

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