You don't need planning permission providing that either, your 'permitted development' rights have not been removed by a condition on a previous planning permission or, the windows and doors are not to a shop front.
Replacement windows and doors must not encroach over roads or private ways.
Bye-laws note: you'll need building bye-law permission to replace windows in a non-domestic building. Building bye-law permission is also required to replace windows in a dwelling if the work is not undertaken by an approved competent person and the department notified of the work within 30 days of completion.
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