The Law and the overwhelming majority of declarations of co-ownership require that syndicates of co-owners insure their building. This may seem surprising at first glance as the syndicate does not own the private portions nor the common portions. However, its main object is to ensure the preservation and the longevity of the building and to manage and administer it diligently following rules of the trade. This is why the legislator has given to the syndicate an insurable interest and has made it compulsory that it subscribe building insurance.
The insurance of the syndicate covers your private portion, with the exception of the improvements in your unit. You must therefore subscribe (on an individual basis) insurance coverage for any such improvements.