Hi Paul, if I recall correctly, the fisc doesn’t actually mandate a required legal amount of time for the property to be deemed residence principale. You need to be living there on december 31st and declare it as your residence principale.
So technically, you could move there, live in it for three months and then sell it on. You would most likely get an inspection from the fisc into your transaction, to prove that you did live there and that it is your principal residence, but might be worth the hassle. Basically it would have to be done in good faith. You would have to move all your accounts/mail there, prove that you have lived there, which is usually done by showing your water and electricity bills. They will check for normal consumption patterns to prove that you were actually in the house and not elswhere.
" Pendant combien de temps faut-il habiter la résidence principale avant la vente ?
Nombreux sont ceux qui évoquent à tort des délais de 6 mois, 8 mois, voire un an d’occupation à titre de résidence principale pour bénéficier de l’exonération des plus-values immobilières. Il n’en est rien, Aucune durée minimale d’occupation n’est prévue dans la loi. Mais attention, une revente après une courte durée d’occupation vous attirera un regard attentif sur votre situation par l’administration fiscale."