AIBU to tell my neighbour about our extension plans before submitting them to the Council, when I have no intention of changing them if he objects?

[WhereDoesThisToiletGo]

Title pretty much says it all.
We are planning a small (2 x 3.5m) extension to the rear corner of our house.
At present there is a "bite" out of the corner of the house nearest to our neighbour, and we want to fill in this corner to extend our kitchen.
The extension will be ground floor only.

I feel it's polite to give him a heads up in advance and possibly explain what it will look like, but if he doesn't like the windows, I don't want to change or remove them.
Due the unusual arrangement of our houses and gardens, this extension means that the nearest point of our house will be 27 metres away rather than the current 28, so it's not going to be very dominant.

I agree it would be polite and if he disagrees that he can submit his reasoning and justification the normal way to oppose planning permission.

Yes I think it would be courteous to shoe him the plans

Show even!

I think it is polite to do so, and wish others felt the same way.

Doesn't hurt to be polite. You'll be living next door to him afterwards.

Of course, if you need planning permission and he has a valid objection you may not have any choice about changing the plans.

I discussed my extension plans with my neighbours - who then told me they were planning to extend also, so in the end we could cooperate!! I think it’s only polite, and you would probably want them to do the same

What makes you think your neighbours may object? Are you reducing their light or are windows in the extension overlooking their garden or into their house? The Council may agree with them if it's for either of those reasons. Otherwise not sure what their objection could be but think it's good to discuss with them before you begin.

Do you actually need pp if it's a small extension?
I would show the neighbour but don't commit to anything - politeness costs nothing and you don't have to change them if you don't want to.

Absolutely tell your neighbours. It would never occur to me not to tell them. Do you need PP?

If you don't intend to change your plans based on any concerns they may have, there's no point in talking to them now. I'd talk to them after planning has been agreed but before building starts. Any earlier implies you would listen to them.

Not reducing light.
Neighbour is nice enough, we rarely speak if only because our gardens adjoin but they are in a different street! About 5 minutes walk from our front door.
I don't think what we are planning is contrary to any Council guidelines. We already have one side window that overlooks across the end of the garden and a rear window that faces down the length of the gardens, looking at their house (albeit from 30 meters away)
We plan to remove the rear facing window that looks at the rear of their house, and replace it with another side facing window (from which you'd have to crane to see their house).
It's just that I know he wasn't keen when the new houses (ours) were planned 20 years ago. He contacted the council suggesting TPOs on all the trees to minimise the scale of the development. Now he is frustrated because we don't /can't cut back our trees every year like he does.

Our area is exempt from Permitted Development

I was going to wait until we had formal drawings done, but before they are submitted. It would be useful to include photos of the house with the application and the only place I can get a proper shot of the house is from his garden