Flood Information – Substantial improvement

When purchasing an old home that’s in a Special Flood hazard Area (SFHA) one should be mindful of the provisions of the town zoning code which are in in compliance with the requirements if the National Flood Insurance Program (NFIP).  Specifically, the definition of substantial improvements.  If substantial improvements are made to the property then the property must be be brought up to the current code as it pertains to both the Florida Building Code (FBC) as well and the NFIP.

The NFIP defines “Substantial improvement shall mean any repair from damage or destruction, reconstruction, improvement, or additions of a structure, the cost of which equals or exceeds 50% of the assessed tax value (you can perhaps also get your own appraisal done) of the structure as is listed by the Palm Beach County Tax Assessors Office or by a certified appraisal. The assessed value of the structure shall be determined before the improvement is started, or if the structure has been damaged and is being restored, before the damage or destruction occurred.”

There was question regards this submitted to the FBC Commission for what’s called a declaratory statement that is as follows:

DEC REQUEST DS-2014-035 STAFF ANALYSIS

ISSUE: DS-2014-035. Kathleen Morgan, Managing Member Leah Marie Enterprises, LLC seeks a Declaratory Statement on the Florida Building Code, Building, Section 1612.2 Substantial Damage and Substantial Improvement Florida Building Code, Existing Buildings, Section 202 Definitions Substantial Damage, Substantial Improvement and Substantial Structural Damage, Section 303.2, Section 304.5 and Section 807.4

Petitioner in DS-2014-035 seeks clarification of the following questions:

            Question 1: Does a voluntary alteration project to a pre-FIRM single-family residential structure involving removal of more than 30% of the truss system in order to create a tray or vaulted ceiling constitute Substantial Structural Damage pursuant to FBC Existing Building Section 202, or is it reviewed as a structural alteration under FBC Existing Building Section 807.4?

            Question 2: If an alteration project is deemed to be Substantial Structural Damage under FBC Existing Building Section 202, is it automatically deemed to also be Substantial Damage for flood design requirements, regardless of whether the project meets the definitions of Substantial Damage and Substantial Improvement in FBC Section1612.2 (ie. The “50% Rule”)?

Situation:

Kathleen Morgan, Managing Member Leah Marie Enterprises, LLC, seeks clarification of code regarding Florida Building Code, Building, Section 1612.2 Substantial Damage and Substantial Improvement Florida Building Code, Existing Buildings, Section 202 Definitions Substantial Damage, Substantial Improvement and Substantial Structural Damage, Section 303.2, Section 304.5 and Section 807.4

Applicable Codes:

Florida Building Code, Building Section 1612.2 Definitions SUBSTANTIAL DAMAGE – Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

            Florida Building Code, Building Section 1612.2 Definitions, SUBSTANTIAL IMPROVEMENT – Any repair, reconstruction, rehabilitation, addition or improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
2. Any alteration of a historic structure provided that the alteration will not preclude the structure’s continued designation as a historic structure.

Florida Building Code, Existing Buildings Section 202 Definitions SUBSTANTIAL DAMAGE – Damage of any origin sustained by a structure whereby the cost of restoring the structure to its before-damaged condition would equal or exceed 50 percent of the market value of the structure before the damage occurred.

Florida Building Code, Existing Buildings Section 202 Definitions SUBSTANTIAL IMPROVEMENT – Any repair, reconstruction, rehabilitation, addition or improvement of a building or structure, the cost of which equals or exceeds 50 percent of the market value of the structure before the improvement or repair is started. If the structure has sustained substantial damage, any repairs are considered substantial improvement regardless of the actual repair work performed. The term does not, however, include either:

1. Any project for improvement of a building required to correct existing health, sanitary or safety code violations identified by the building official and that are the minimum necessary to assure safe living conditions.
2. Any alteration of a historic structure provided that the alteration will not preclude the structure’s continued designation as a historic structure.

Florida Building Code, Existing Buildings Section 202 Definitions SUBSTANTIAL STRUCTURAL DAMAGE – A condition where:

1. In any story, the elements of the lateral force-resisting system have suffered damage such that the lateral load-carrying capacity of the structure in any horizontal direction has been reduced by more than 20 percent from its pre-damaged condition; or
2. The capacity of any vertical load-carrying component, or any group of such components, that supports more than 30 percent of the total area of the structure’s floor(s) and roof(s) has been reduced more than 20 percent from its pre-damaged condition and the remaining capacity of such affected elements, with respect to all dead and live loads, is less than 75 percent of that required by the Florida Building Code, Building for new buildings of similar structure, purpose and location.

Florida Building Code, Existing Buildings Section 303.2 Flood hazard areas. – For buildings and structures in flood hazard areas established in Section 1612.3 of the Florida Building Code, Building, any alteration that constitutes substantial improvement of the existing structure, as defined in Section 1612.2 of the Florida Building Code, Building, shall comply with the flood design requirements for new construction, and all aspects of the existing structure shall be brought into compliance with the requirements for new construction for flood design. For buildings and structures in flood hazard areas established in Section 1612.3 of the Florida Building Code, Building, any alterations that do not constitute substantial improvement or substantial damage of the existing structure, as defined in Section 1612.2 of the Florida Building Code, Building, are not required to comply with the flood design requirements for new construction.

Florida Building Code, Existing Buildings Section 304.5 Flood hazard areas – For buildings and structures in flood hazard areas established in Section 1612.3 of the Florida Building Code, Building, any repair that constitutes substantial improvement of the existing structure, as defined in Section 1612.2 of the Florida Building Code, Building shall comply with the flood design requirements for new construction, and all aspects of the existing structure shall be brought into compliance with the requirements for new construction for flood design. For buildings and structures in flood hazard areas established in Section 1612.3 of the Florida Building Code, Building, any repairs that do not constitute substantial improvement or substantial damage of the existing structure, as defined in Section 1612.2 of the Florida Building Code, Building, are not required to comply with the flood design requirements for new construction.

Florida Building Code, Existing Buildings Section 807.4 Structural alterations – All structural elements of the lateral-force-resisting system in buildings undergoing Level 3 structural alterations or buildings undergoing Level 2 alterations as triggered by Section 707.5 shall comply with this section.

Exceptions:

1. Buildings of Group R occupancy with no more than five dwelling or sleeping units used solely for residential purposes that are altered based on the conventional light-frame construction methods of the Florida Building Code, Building or in compliance with the provisions of the Florida Building Code, Residential.
2. Where such alterations involve only the lowest story of a building and the change of occupancy provisions of Chapter 9 do not apply, only the lateral-force-resisting components in and below that story need comply with this section.

807.4.1 Evaluation and analysis.

An engineering evaluation and analysis that establishes the structural adequacy of the altered structure shall be prepared by a registered architect or engineer and submitted to the code official.

807.4.2 Substantial structural alteration.

Where more than 30 percent of the total floor and roof areas of the building or structure have been or are proposed to be involved in structural alteration within a 12-month period, the evaluation and analysis shall demonstrate that the altered building or structure complies with the Florida Building Code, Building for wind loading.

807.4.3 Limited structural alteration.

Where not more than 30 percent of the total floor and roof areas of the building are involved in structural alteration within a 12-month period, the evaluation and analysis shall demonstrate that the altered building or structure complies with the loads applicable at the time of the original construction or of the most recent substantial structural alteration as defined by Section 807.4.2.

Background:

Kathleen Morgan owns a single family home and seeks permits to remove portions of the existing truss system in order to create a tray or vaulted ceiling.  More than 30% of the existing truss system would be removed and approximately 60% of the total existing roof area would be altered. The City of Holmes Beach has suggested that because more than 30% of the roof area has been removed during the course of the project, the project would constitute Substantial Structural Damage under the Florida Building Code, Existing Building Section 202. The City also suggest that the project would constitute Substantial Damage for the purpose of flood design requirements even if the project does not meet the “50% Rule” as described in the Florida Building Code, Building Section 1612.2.

Staff analysis:  Based on the above facts and circumstances, staff provides the following answers to proponent’s questions:

Question 1: Does a voluntary alteration project to a pre-FIRM single-family residential structure involving removal of more than 30% of the truss system in order to create a tray or vaulted ceiling constitute Substantial Structural Damage pursuant to FBC Existing Building Section 202, or is it reviewed as a structural alteration under FBC Existing Building Section 807.4?”,

Answer/Petitioner:  Petitioner asserts that the project would not be classified as “Substantial Structural Damage” and would be reviewed under 807.4.

Question 2:  If an alteration project is deemed to be Substantial Structural Damage under FBC Existing Building Section 202, is it automatically deemed to also be Substantial Damage for flood design requirements, regardless of whether the project meets the definitions of Substantial Damage and Substantial Improvement in FBC Section1612.2 (ie. The “50% Rule”)?”

Answer/Petitioner:  Petitioner asserts that the answer is no.  Regardless of the impact to the roof system, flood design requirements for new construction are only triggered if the project exceeds the “50% Rule”, as described in the definition of Substantial Damage and Substantial Improvement in FBC Section 1612.2.