I got a message back from someone else about an hours drive away building a GREB house with a similar budget to us. They have a new baby so are pretty busy right now but are happy to be in touch so I will email him back asap.
He recommended getting in touch with the free architect, CAUE, and also with Ariege Conseil Energies Renouvenables (http://acer09.fr). I’ve seen that site before and now I have a recommendation I’ll follow up with them. I’d sent an email to the CAUE in Carca back on 10/10 so have sent a chaser message to them.