Debbie is considering purchasing a new home for $250,000 by borrowing 80% of the purchase price. She has two financing options:

• Option 1: Fixed rate mortgage over 30 years at 5.15% interest, zero points
• Option 2: Fixed rate mortgage over 30 years at 4.70% interest, plus two discount points

How long (in months) would her financial planner recommend that she live in the house to justify Option 2? Assume that the discount points are not included in the mortgage but paid upfront.