EU REGULATION 650/2012
From 17th August 2015, under EU Regulation 650/2012, the general rule across the EU Countries that signed up (that is all EU States except the UK Ireland and Denmark) is that the law of the country of your habitual residence applies to all of your assets, including real estate held within a different EU Country.
However, an individual may instead opt for the laws of their nationality to apply instead - even if this country is outside of the EU.
Therefore, this will allow non-French nationals to apply the laws of their nationality on their deaths to their assets - including French real estate. For UK nationals, with a new Will including an election to use the succession laws of the country of their birth, this means that they can now choose how to leave their assets - as opposed to the prescriptive French laws.