Tax exemption on second house for joint ownership

hi,

I already own a flat on joint ownership with my wife where she is the co-owner and co-borrower too. If i intend to buy a second flat i supppose one of the flats will become deemed let out and we could choose which one. If i pay back my earlier loan on my first house what all tax benefits can i avail on the loan borrowed for the second house under 80c and 24b please or do you suggest not fore closing my earlier loan and continue with both loans to avail maximum tax benefits?