Connecting two neighboring apartments in a joint-ownership apartment building

I own two apartments on the same floor of an apartment building and would like to connect the two apartments by way of one or more doors. From a construction standpoint this would be easy, but what about the legal standpoint? Do I need to get permission from all the apartment building’s co-owners? There are more than ten of them.

In Switzerland, the walls and floors of a condominium are collective property, meaning they belong to all of the building’s owners. You cannot make alterations to these without the approval of all co-owners.