Hypothetical E.U. question

[Teal Lantern]

If you have residency in E.U. country A and move to live and work in E.U. country B and build a life there, what would happen to your property and residency rights in E.U. country B if the union breaks up?

[Yohan]

Nothing will happen, you continue as before.

There are plenty of bilateral agreements too. Many Germans for example have a second address and condominium in a resort village in Austria.
Many Austrians have a bungalow/small plot in Italy. Many UK-citizens are living in Spain and own some accommodation etc.
Even before EU it was possible to own some land and to get a working permit in most other countries in Europe.

Only a few European countries are difficult in their administration and still are not EU members, especially Norway. also Switzerland can be difficult for long-stay, working permit etc. but in both countries Europeans can stay for months as a tourist without hassles.

There is a difference between political issues and economic issues. Might be politically something will change in future, but there is no reason to restrict free trade agreements and movement of people.