Rebuilding Equity Act of 2012 - Requires the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac) (government sponsored enterprises or GSEs) each to establish a voluntary program for eligible borrowers who qualify for the Home Affordable Refinance Program carried out by the GSEs, under which the GSEs shall pay up to $1,000 of the closing costs associated with applying for and receiving refinancing when the borrower agrees to refinance a 30-year mortgage loan into a fully amortizing loan with a term of not longer than 20 years. Requires the subject property to have a loan-to-value ratio of not less than 105%.