Exemption of the top up of home loan's principal & its ints.

Repayment of Housing Loan Principle is eligible for deduction u/s 80C but in case of one housing loan only. But if top-up loan is obtained on same loan account, you shall be eligible for the deduction even on increased principle repayment but subject to max. deduction Rs. 1 lakh. 

For interest deduction u/s 24 the limit is applicable depending upon whether House is self occupied or let out. If House is self occupied deduction is limited to Rs. 1,50,000/-. However if house is actually  let out or treated as deemed let-out for income tax purpose, then there is no limit for deduction.

i have some doubt that deduction is available or not becasue original housing loan is for purchase/construction of house but top up loan is for something else