Colin Wilson wrote:
I need to replace a wooden 'Georgian' style window that is rotten.

ISTR there being a requirement to involve the local council / planning
regs (?) if you`re fitting plastic windows yourself - if a company is
doing it they have a different licensing system to allow them to just go
ahead...

Definitely - you need to go through building regs (submit a 'building
notice', which is likely to cost you 50-100 GBP, depending on where you
are). They will need to check the window fulfil current requirements
for insulation, emergency exit in a fire etc. DG companies are normally
members of FENSA which allows them to self-certify.

No need for planning permission if you are just replacing a window
(rather than making a new opening)

David