Pub 936

  Refinancing. Generally, points you pay to refinance a mortgage are not deductible
   in full in the year you pay them. This is true even if the new mortgage is secured by
   your main home. 

   However, if you use part of the refinanced mortgage proceeds to improve your
   main home and you meet the first five tests listed under the Exception, earlier,
   you can fully deduct the part of the points related to the improvement in the year
   paid. You can deduct the rest of the points over the life of the loan.