Q: My brother for the last 8 months has saved money to build his house, plus he received a substantial amount as a qardh-e-hassan. How and when will he calculate his zakaat since he is currently building his house?
A: If his debts are greater than his assets then he is not liable for zakaat.
And Allah Ta’ala (الله تعالى) knows best.
( وسببه ) أي سبب افتراضها ( ملك نصاب حولي ) نسبه للحول لحولانه عليه ( تام ) … ( فارغ عن دين له مطالب من جهة العباد ) .( الدر المختار 2/259)