The interest money derived from saving account is haram and malicious. Its right use as per the Islamic Faqih is to give it in charity to the poor, needy, miserable debtor etc without the intention of reward. It is not lawful to spend it in construction work as it does not carry the provision of tasadduq (tamlik). Yes, if that interest money (less than the quantity of nisab) is given in the possession of some poor person then he spends it in the construction of graveyard, then it is allowable. But it is not lawful to collect zakah money for this purpose and spend it after this process of hila.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband