Capital gains on principal residence (Paris)

We are currently in the process of moving to the US and has put our house on sale. My husband is French and I'm Canadian. It looks like we will most likely sell our house after we leave France. So the question on whether or not the capital gain is taxable is questionable. My husband benefit from an exemption as he is French but in my case it is not clear. We consulted an agency SARF which is accredited by the government as the tax specialist and they can't even confirm the issue! Anyone out there in the same situation?