Deductions u/s 24(b)

I don't think the husband can claim the entire deduction u/s 24(b). Both will have to claim deduction equally each year in their ITR. 

If wife is not claim any thing one letter by her stating that she is not claiming any deductions is enough for claim full amount by husband it is possible.

Dear Anantmoorti,

If Assessee is Spouce then deduction u/s 24(b) can claim by either both (50% each, as debt taken by both) or any one can take 100% deduction.

Each and every co-owner/joint owners are entitled to claim deduction of interest u/s 24(b) payable against capital borrowed . Each co-owner/joint owner can claim deduction upto a maximum of Rs. 1.5 Lakh per annum, if loan is acquired for construction/acquisition of house property or Rs. 30 K per annum, if loan is acquired for repair of house property. 

If the house property is let-out, then the deduction aforementioned is without limit, subject of course, limited to the amount to be paid to the bank.

 Thus in the present context, both Husband and wife can claim the deduction of interest paid/payable against the loan availed, since both are entitled to such deduction. However, if the wife cannot avail deduction for certain reasons (assuming that she does not have any taxable income earned during the year), her husband can claim his share of deduction subject to the limits as mentioned above. 

To make the above simple, consider the following example:

Interest Payable/Paid during the previous year                  Rs.2,00,000

Entitlement of deduction to both Husband and Wife           Rs.1,00,000

(Having equal share in property)

As per your query, if wife cannot claim the deduction, then:

Her husband can claim Rs. 1,50,000 (if not let-out)

or Rs. 2,00,000 (if let-out)

P.S.: In addition to interest deduction, they are entitled to deduciton u/s 80 C of principal repaid during the previous year. 

my question is,if father is owner of property and they want to construct a second floor and they take a loan jointly with son.is this construction or addition.or should they  both take deduction u/s 24b and 80c.they both py emi equally.

The basic criteria in the provision u/s 24(b) is the ownership in the property. Once the ownwership is established, he/she is entitled to the deduction. In your case, Sanchit, both father and son should have ownership in the second floor. It does not matter if father owns the land and other floors. To claim the deduction in additional floor, one needs to be the owner of that floor. Mere payment of EMI does not suffice.