Home Building Lending Improvement Act of 2013 - Directs each of the appropriate federal banking agencies to initiate guidance or rulemaking with respect to financial institutions under their respective jurisdictions that make real estate loans to home builders.

Requires such rulemaking to provide for: (1) adjustment from 100% to 125% of bank capital the measurement that triggers additional scrutiny on real estate loans in the lending portfolio of any qualified financial institution, (2) a prohibition against compelling lenders to call loans in good standing, and (3) improved composite ratings of a financial institution to take effect immediately.

Prohibits a federal banking agency from preventing a qualified financial institution from making a real estate loan to a home builder in good standing that is secured by a viable project, unless there is a legitimate supervisory or accounting reason to do so.

Prohibits such banking agencies from requiring a financial institution to reclassify any real estate loan to a homebuilder in good standing on the balance sheet of such institution, unless there is a legitimate supervisory or accounting reason to do so.

Prohibits such agency guidance and regulations from superseding state law, except to the extent of state law inconsistency.