Cost of consent for external wall insulation.

Just wondering if anyone has gone through the consent process for external wall insulation? If so how much did it cost?

I assume there is cost of consent (including people coming to check) plus architecture drawings cost?

I know this will vary from region to region but just looking for ball park.

Don’t have a house yet but just trying to get ballpark idea. No house I’ve checked out has wall insulation. That and double glazing will be the first thing to get done.

Thanks