Is zakat obligatory on an amount of 16,000 dinars saved to buy a house, which has been held for a full year and from which 500 dinars in interest has been gained, knowing that a property was purchased with this amount after one year?

Zakat is obligatory on money saved to buy a house if it reaches the نصاب (the equivalent of 85 grams of gold) and one lunar year has passed. The zakat to be paid is one-quarter of one-tenth (2.5%). Zakat is not waived by the passage of time. It is not permissible to deposit money in an interest-bearing bank unless there is a necessity, and usurious interest is not subject to zakat; rather, it must be disposed of by spending it on charitable causes.