What changes for second-home owners

France does not have a special immigration/residency status for second-home owners. 

If you are a non-EU national and are coming into France from outside the Schengen area you will be subject to EES as for ordinary visitors. 

However there is an exception if you have a temporary longstay visa (this is often used for stays of four to six months at a second home) as the EU states that holders of long-stay visas will be exempt from EES requirements. 

Note too that time on a long-stay visa is not counted as part of the 90/180 days rule. You can find out more about temporary long-stay visas at this link.