I'm a UK citizen and have been a permanent resident in NZ for 16 years. My son lives in Pantin just outside Paris,with his french wife. My Kiwi wife and I probably have one visit left in us and I would like to stay for approximately 6 months and time it for the arrival of our grandchild. I understand I can stay for 90/180 and can apply for an extension.
1) would I apply for an extension before I leave NZ or while I'm in France ?
2) would wanting to spend time with family be reason enough to gain an extension.
Thanks

You need to apply for a visa at the French embassy in NZ.
I French friend recently returned to France with his South Korean wife who he thought would be allowed to stay.
Before the end of the 90 days she had to return to SK and apply for a visa.
HTH

2 sec search on google.
https://france-visas.gouv.fr/en/web/...long-stay-visa

Sometimes it's easier to understand, or just nicer, to hear it from someone who isn't a government website, but thanks for your input.

... actually, government websites are the most reliable for up-to-date info, but I appreciate that you'd prefer some human input....
As suggested, enquire at the French Embassy/Consulate in NZ, as apparently BE members in France haven't been there, done that.....
At the risk of pouring oil on the flames, here's the French Embassy website:
https://nz.ambafrance.org/-Visas-and-travel-info-
As an anecdote, my parents came over from England to look after DD1 while I was at the Maternité and an uncomfortable fortnight was spent by all, as DD2 was two weeks' late. Luckily my French in-laws weren't involved, too....

@DMU, "As an anecdote, my parents came over from England to look after DD1 while I was at the Maternité and an uncomfortable fortnight was spent by all, as DD2 was two weeks' late. Luckily my French in-laws weren't involved, too...."
Now I'm just wondering, that was under the reign of which Louis......?
Seriously though, it seems that you've had as many years in France as myself, as I can recall the names of 8 Presidents, and at least 17 Prime Ministers (although there were probably more). Socially speaking I think you'd agree we've seen better times here in the past.
Good to see you appear to be settling well into your new environment, and continuing your helpful, informative posts.

I missed out on de Gaulle, I arrived in 1969 before Pompidou died (cause and effect?). I almost forgot Flamby in the list of Presidents that I've lived through....

It's not hard to forget him.
A few classic moments: