Keeping the house empty is uneconomical, Because under Income tax Act only one house can be treated as self occupied and if second house is vacant then you will have to offer notional income (estimated rental value) as Income and claim deduction of Interest against such notional income. Better option is give it on rent and offer rental income in the hands of both and claim full amount of interest without any ceiling of Rs 1.5 lakhs against rental income i e 50% of interest in the hands of yours and your spouse.