A large part of our work is in London's conservation areas and listed buildings. We know what planners require, what glazing options are accepted, and how to specify windows that will be approved.
We are based in the Royal Borough of Kensington and Chelsea - one of the most heavily conservation-designated boroughs in England, where nearly three-quarters of the area carries conservation area status. The majority of the work we do has some planning sensitivity attached to it.
We understand what conservation officers look for. Materials, profiles, glazing bar widths, ironmongery, and finish all affect whether a replacement window will be approved. At every survey, we give you a clear view of what's achievable before you commit to anything.
In a conservation area, replacing windows that are not like-for-like typically requires planning permission or a Certificate of Lawfulness. Repairs and draughtproofing usually don't. We'll tell you clearly which applies to your project at survey.
Glazing is the most common sticking point. Standard double glazing units are frequently refused because the unit thickness alters the sightlines of the glazing bars. We typically specify slimline double or vacuum glazing for conservation properties - both of which have much better acceptance rates.
Since June 2026, like-for-like timber double-glazed replacement windows are permitted without planning permission in RBKC - a meaningful change that opens options for homeowners across Kensington and Chelsea.
Listed building consent is required for any works affecting the character of a listed building. Single glazing is almost always specified by Historic England for Grade I and II* buildings. For Grade II buildings, vacuum glazing is increasingly accepted on a case-by-case basis - we have experience of projects where this has been approved.
Profile matching on listed buildings is critical. We take detailed measurements of existing profiles, bar widths, horn details, and bead configurations at survey, and order manufactured to replicate these exactly.
~75% conservation area coverage. We work extensively across W8, SW3, SW5, SW7, SW10 - including Onslow Square, Edwardes Square, and the listed streets of north Kensington.
Over 50 conservation areas including Belgravia, Mayfair, Bayswater, and Pimlico. Georgian and early Victorian stock with significant planning sensitivity throughout.
W11 and W14 feature stucco terraces and Victorian townhouses in several conservation areas. Mixed glazing requirements - slimline double usually appropriate for non-listed properties.
Planning requirements for window work vary depending on whether your property is in a conservation area, is listed, and which local authority you're in. Getting it wrong - fitting windows that haven't been approved, or paying for an application when permitted development applies - costs time and money.
At every survey we assess the planning context of your property and give you a clear view of what we believe will and won't be approved, before you commit to anything. For straightforward cases this is part of the survey at no extra charge.
For more complex cases - particularly listed buildings or boroughs with stricter conservation officers - we can provide a written planning assessment to support your application or pre-application enquiry.
Book a consultation →A condition report is a written assessment of every sash window in your property, produced following a site visit. It covers the condition of each window, identifies specific faults, and makes a clear recommendation - repair, partial replacement, or full replacement.
They're useful for buyers and sellers of period properties wanting an independent view of the window stock before exchange, for landlords managing portfolios across multiple buildings, and for freeholders where windows are the subject of service charge discussions.
The report can also support a planning application or listed building consent by demonstrating the condition of the existing windows and the case for the proposed works.
Request a condition report →Every property is surveyed in person - no estimates from photos, no hard sell.