Homeowner Flood Insurance Affordability Act of 2013

Homeowner Flood Insurance Affordability Act of 2013 - Prohibits the Administrator of the Federal Emergency Management Agency (FEMA) from implementing a requirement of the National Flood Insurance Act of 1968 (NFIA) that would: (1) increase flood insurance risk premium rates to reflect the current risk of flood for certain property located in specified areas subject to a specified mandatory premium adjustment, or (2) reduce statutory subsidies for any property not insured by the National Flood Insurance Program (NFIP) as of July 6, 2012, or any policy that has lapsed in coverage as a result of the policyholder's deliberate choice (pre-Flood Insurance Rate Map or pre-FIRM properties). Sets an expiration date for such prohibitions six months after one or another of three specified alternative events takes place.

(A pre-FIRM property contains a structure neither constructed nor substantially improved after the later of December 31, 1974, or the effective date of the initial flood insurance rate map published by the FEMA Administrator under NFIA for the pertinent area.)

Amends the National Flood Insurance Act of 1968 (NFIA) to prohibit FEMA from providing flood insurance to prospective insureds at rates less than those estimated for property purchased after the expiration of such six-month period (currently, any property purchased after July 6, 2012).

Prohibits FEMA from reducing the risk premium rate subsidy for flood insurance for a property purchased on or before the expiration of the same six-month period based upon the fact that: (1) the property was not insured by NFIP as of the date of enactment of the Biggert-Waters Flood Insurance Reform Act of 2012, or (2) on or before the expiration of the six-month period the policy for the property had lapsed in coverage owing to the policy holder's deliberate choice because the property was no longer required to retain such coverage.

Directs FEMA to: (1) restore during such six-month period specified estimated flood insurance risk premium rate subsidies for certain pre-FIRM properties with respect to which FEMA is not allowed to implement certain prohibitions against subsidies to new or lapsed policies; and (2) submit to certain congressional committees a draft affordability framework addressing the affordability of flood insurance sold under NFIP.

Prescribes procedures for expedited congressional consideration of legislation on FEMA affordability authorities.

Permits FEMA to enter into an agreement with another federal agency either to: (1) complete the affordability study, or (2) prepare the draft affordability framework.

Directs FEMA submit to certain congressional committees the affordability study and report.

Amends NFIA to authorize FEMA to reimburse homeowners for successful map appeals.

Makes any community that has made adequate progress on the construction (as under current law) or reconstruction (new) of a flood protection system which will afford flood protection for the one-hundred year frequency flood eligible for flood insurance at premium rates not exceeding those which would apply if such flood protection system had been completed.

Revises guidelines governing availability of flood insurance in communities restoring disaccredited flood protection systems to include riverine and coastal levees.

Requires FEMA to: (1) rate a covered structure using the elevation difference between the floodproofed elevation of the covered structure and the adjusted base flood elevation of the covered structure; and (2) designate a Flood Insurance Advocate to advocate for the fair treatment of policy holders under NFIP and property owners in the mapping of flood hazards, the identification of risks from flood, and the implementation of measures to minimize the risk of flood.