Who decides what is acceptable, and the specification details that usually make the difference.
In a conservation area or a listed building, your local planning authority — not the installer — decides what is acceptable. The practical route is to understand what is usually approved before you fall in love with a product.
Conservation area controls focus on the appearance of the street scene, particularly on elevations visible from a public highway. Listing protects the building itself, inside and out, and consent requirements are stricter.
Sightline width, glazing bar type, the presence of horns on sashes, the reveal depth and how the frame sits within the opening are the usual points of scrutiny.
Talk to the conservation officer early with a specification sheet. It is far cheaper than ordering a product that has to be removed. We will provide the technical detail needed for that conversation.
We'll put together the specification detail your conservation officer will want to see.
Sometimes — it depends on the authority and the elevation. Heritage profiles are much more likely to be accepted than standard ones.
Frequently yes. Assume consent is required and confirm with the local authority before ordering.
Slim units, warm-edge spacers and improved seals deliver a large improvement while keeping the original appearance.