Code Effective Date: December 28, 2010 (2010 Editions) U P D A T E D
Topic: Procedure for Evaluation of Flood Damaged Buildings or Improvements to an Existing Building
Questions have arisen regarding the procedure for plan review for new buildings and additions in the flood plain, and for the evaluation of improvements to an existing building and flood damaged buildings, to determine if the required proposed work in the building is a substantial improvement. "Substantial improvement" is defined in the Federal Emergency Management Agency (FEMA) regulations for the National Flood Insurance Program (44 CFR 59.1) as being based on 50 percent of market value of the building. If the building is damaged or to be improved, a licensed Real Estate Appraiser shall ascertain the market value of the building before the improvement or repair of the damage. Market value is usually determined by comparison to other like or similar buildings in the immediate area and usually has no relationship to the assessed value for tax purposes. FEMA guidance allows use of assessed value of the structure (not including the land) divided by the full value assessment ratio and shall be provided to the code enforcement official, or other local authority involved, for review for a building permit.
New buildings and substantially improved buildings in flood hazard areas (including A Zone) or coastal high hazard areas (including V Zone) are required to have the lowest floor elevated above the design flood elevation (DFE) plus the appropriate freeboard of two feet for a residential structure, or as determined by ASCE 24-05 for other structures. DFE is the elevation of the "design flood," (including wave height) relative to the datum specified on the communityís legally designated flood hazard map. Additions which are a substantial improvement are required to comply. See Existing Building Code of New York State Section 1003.5, Flood hazard areas and Residential Code of New York State Section J803. See definition of "substantial improvement."
The DFE is used to define areas prone to flooding, and describe, at a minimum, the base flood elevation (BFE) at the depth of peak elevation of flooding (including wave height) which has a 1 percent (100-year flood) or greater chance of being equaled or exceeded in any given year. The BFE is the elevation of the base flood, including wave height, relative to the National Geodetic Vertical Datum (NGVD), North American Vertical Datum (NAVD) or other datum specified on the Flood Insurance Rate Map (FIRM). New and replacement manufactured homes (HUD seal) shall be elevated in accordance with the above requirements and shall have appropriate anchors and tie-downs.
An individual who is a registered architect (RA) in accordance with Article 147 of the New York State
Education Law or a licensed professional engineer (PE) or licensed land surveyor in accordance with
Article 145 of the New York State Education Law shall layout the placement for an addition, a new building or document the layout (land survey) for a substantially damaged building or a building to be improved. The land survey for a new building and for a substantially damaged building, the as built, shall be provided to the code enforcement official for review for a building permit. A registered design professional shall certify that the design and methods of construction to be used meet the applicable criteria and submit such to the code enforcement official for review for the building permit. Upon completion of the building the registered design professional shall document the final placement and elevation of a new building and a substantially damaged building.
New buildings required to meet the requirements of Residential Code of New York State Section R324 or Building Code of New York State Section 1612, respectively. For a summary of these requirements see the Technical Bulletin entitled "Flood Venting in Foundations and Enclosures Below Design Flood Elevation." If there is less than substantial damage, there is no requirement under floodplain requirements to comply with flood codes for older structures that were not constructed under the FEMA flood codes. In buildings in need of repairs, where the damaged less than substantial, only the repairs are required to comply with the codes.
For buildings that are substantially improved, or have been substantially damaged, new and replacement electrical equipment, heating, ventilating, air conditioning, plumbing connections, and other service equipment shall be located at or above the DFE. Electrical wiring and outlets, switches, junction boxes and panels shall be elevated to or above the DFE unless they conform to the provisions of the electrical part of the codes for location of such items in wet locations. Duct systems shall not be installed below the DFE. New and replacement water supply systems shall be designed to minimize infiltration of flood waters into the systems in accordance with the plumbing provisions of the codes. New and replacement sanitary sewage systems shall be designed to minimize infiltration of flood waters into systems and discharges from systems into flood waters in accordance with the plumbing provisions of the codes. Building materials used below the DFE shall comply with the following:
1. All wood, including floor sheathing, shall be pressure-preservative treated in accordance with AWPA U1 or decay-resistant heartwood or redwood, black locust, or cedars.
2. Materials and installation methods used for flooring and interior and exterior walls shall conform to the provisions of FEMA/FIA-TB-2.
3. All flood vents and air vents are required to comply with FEMA TB-93-1.
As a aide to compliance for registered architects, licensed professional engineers, land surveyors and code enforcement officials, see the following plan review and inspection checklists:
Additionally, for each building subject to flood hazard requirements, that is new, an addition and substantially damaged, an Elevation Certificate is required to be provided by the registered design professional to the code enforcement official, to certify the elevation information, so that the community can maintain a record of the elevations for flood insurance purposes within the community. The Elevation Certificate is a standard form provided by the National Flood Insurance Program.
Inspection of Gas Piping Installations
There have been reports that some local governments responsible for code enforcement have not been conducting or otherwise providing for inspections of gas piping and vent installations, as well as installation of gas-fired appliances. These installations must be approved as part of the permitting and inspection process, as provided for in Part 1203, minimum standards for administration and enforcement of the uniform code. Specifically, section 1203.3(b)(2)(v) requires inspections of building systems, including underground and rough-ins.
While it is a standard practice for code officials to accept electrical inspection certifications, a different situation prevails with regard to gas installations. Unlike electrical installations and associated inspections, there are generally not independent third party inspection agencies, which are not associated with either the installer or the public utility providing supplies or transport of natural gas or LP-gas. Therefore, the required inspections must be performed by the code enforcement official, or an entity that provides the principal part of an administration and enforcement program. Relying on the utility provider for the inspection or the self certification from the installation contractor is an unacceptable practice.
If necessary to fulfill this responsibility, local governments should adjust their provisions for inspections at appropriate intervals. In addition to distribution piping rough-in, there should be provisions for inspection of gas vents and the installation of appliances. Special attention should be paid when corrugated stainless steel tubing is utilized for gas distribution, as described on the Divisionís website, at http://www.dos.state.ny.us/code/CSST.htm.