You may select your home "sur plan", ie housing that is not yet built even if you have not yet bought the land and obtained the
building permit « permis de constuire ».
For this, you must sign a contract of booking « contrat de réservation ». By signing you can be sure that the seller reserves it but you must also pay a deposit « dépôt de garantie », a kind of bond.
Your contract booking, once signed, must be sent to you by mail in a letter with acknowledgment of receipt « recommandé avec accusé de réception ». When you receive it, you have 7 days to change your mind "vous rétracter" by sending a letter with acknowledgment of receipt. After this time, your reservation can not be denied (except in very specific cases such as failure to obtain the loan to finance the purchase and construction).
As for housing already built, the final bill of sale is signed at a notary « notaire ».
As for housing already built, check with the council « mairie » what urbanismes projects are planned around your
If you buy in a future subdivision, make sure what charges, bonds are in the resolution of this subdivision « règlement du lotissement ».
You must receive the "projet de vente" at least 1 month before signing the deed of sale at the notary.
Where do I have to file a « permis de constuire » ?
A building permit is deposited at the town hall « mairie » of the construction. It is valid for 2 years.
As there are many rules concerning building construction, check with an architect (you'll find details of the architects of your city or region in the Yellow Pages telephone directory). But you do not have to take an architect until your project is less than 170m2.