Coventry City Council names 19 conservation areas in the city and states that "In a conservation area you may need planning permission and building regulations approval for some alterations and extensions, which would normally be permitted, and conservation area consent if you want to carry out demolition work." On Article 4 directions it states that "Not all conservation areas have an Article 4 Direction", and that a direction "might relate to replacement windows, the demolition of front garden walls, roof extensions, or other alterations". It records an Article 4(1) Direction made on 8 July 2025 covering properties in Burges, Chauntry Place, Hales Street and Palmer Lane.
The Planning Portal states that planning permission is not usually needed for the "insertion of new windows and doors that are of a similar appearance to those used in the construction of the house". It adds that "If your house is in a designated area (conservation area, national park, area of outstanding natural beauty) there may be additional restrictions in place", and that listed building consent is needed for significant works to a listed building.
The same source states that "Since 1 April 2002 building regulations have applied to all replacement glazing", and gives two routes: "an installer registered with the relevant competent person scheme", who hands over a certificate on completion, or an unregistered installer or do it yourself, "in which case approval can be sought from the relevant Building Control Body".
We would explain how you check the conservation boundary, any Article 4 direction and the proposed work before confirming whether permission is needed. Beside it, the scheme you are registered with and what the certificate you issue actually says.