Inside a conservation area with an Article 4 direction
Planning first, then the window
Reigate and Banstead council says Article 4 directions cover most houses in most of its conservation areas. Its 2026 draft appraisals for Reigate Town Centre and Somers Road say that switching timber windows to uPVC or aluminium, or changing their style, needs planning permission wherever the window faces a road or open space.
The council's guidance on these streets is plain: repair the originals where possible, and match material and detail where they must be replaced. For a street-facing sash on Raglan Road or Somers Road, that usually means timber.
The back of the house is different. A rear bedroom window that faces a private garden is outside those controls on most houses, so the cheaper frame is often fine there.

