To get your family visa, your rental agreement needs be registered with the municipality. In 'theory' it's the owner/landlords responsibility to register the agreement. In reality, many of the owners don't do this and there are quite a few properties that this isn't possible for. Any villas that have been split, I don't believe it's possible to register the agreement as it will have been done unofficially.
It's a nightmare situation for people wanting to bring families over at the moment.
Not 100% sure that you can register the lease yourself, but the government charge would be 1% of the annual rent.