What is the zakat on investment and residential real estate?

The rulings regarding real estate zakat are summarized as follows:

1. Real estate used for personal residence or given to others for residence is not subject to zakat. 2. Real estate prepared for rent: Zakat is not obligatory on its value, but rather on its revenue (rental income) if it reaches the nisab and a full year has passed over it. 3. Real estate considered as trade goods (prepared for sale): Zakat is obligatory on its market value if it reaches the nisab and a full year has passed over it. It is re-evaluated each year at market price. It is permissible to postpone its zakat for someone who does not possess the money for the zakat until funds become available or the property is sold. Then, he must pay zakat for all the past years. The amount of zakat in all cases is 2.5%.