Massallah pertaining to Zakaah

I own a flat worth about 2million which I stayed at for 10 years. I have moved and the flat is now empty for the past 8 months. I do not owe any money on the flat. Is this due for zakaat if I keep it unoccupied for 1 year.
What is the situation if I rent the flat for a net monthly amount of R5000.00.
Jazakaalh.