You can only one home. Your father can only own one. Your mother can only own one.
If there is more than one home in your name, it gets redistributed through a lottery system.
For eg, people who have been in Berlin for one year or more but do not have a home can participate in the lottery. No outsiders allowed. No corporations allowed. Kids can still inherit their parents property.
Would redistribute housing very effectively and stop it's treatment as an investment as you can only own one.
It would also bring down rent prices as the housing supply wouldn't be controlled by a few people. Though tenants would now be responsible for maintaining the home and for utilities.
For apartments, one flat = one home. For maintanence of apartments, owners have to pool together their money to pay the private or public company which can maintain it.