We have recently been made aware of a problem with state and municipal code officials in New Jersey incorrectly applying DEP and municipal zoning regulations that govern required height of first floor when raising a house in a flood zone.
The following is a basic explanation; determing actual requirements for any particular house may be somewhat more involved.
For further discussion, the term "structure-line" is defined as follows;
-- For A and AE Flood Zone: Lowest (usually first) floor of house, considered to be top of floor sheathing
-- For V and VE Flood Zone: Low edge of "lowest structural member", typically a main beam (girder) that supports floor joists.
New Jersey DEP regulations require that, for tidal flood areas, the structure line must be at least one-foot higher than the design flood elevation, which DEP defines to be the base flood elevation (BFE) specified by FEMA using "best available data".
Note that, for "fluvial" flood areas (where flooding is caused primarily by flooding of river or stream, not by tidal action), DEP defines the BFE to be one-foot higher than the FEMA-specified flood elevation. This difference, compared to flood elevation defined for tidal flood areas, may be the source of problems with code officials misinterpreting DEP regulations.
Based on definition used by FEMA (see Coastal Construction Manual), "freeboard" is the amount that that the structure-line is above the BFE.
Municipal zoning ordinances may (are allowed to) specify a freeboard amount that is greater than the one-foot minimum required by DEP.
For a recent residential project in Stafford Township, NJ, local code officials incorrectly claimed that the BFE to be used for purposes of building code provisions was one-foot higher than the FEMA-specified BFE. They maintained this incorrect position even when presented with overwhelming evidence showing they were incorrect. They went so far as to require the contractor to spend several thousand dollars to "correct" an issue based on their incorrect application of regulations. Eventually, when presented with facts of the case, a state DCA official effectively backed-off the incorrect claim (although in a back-handed manner).
Unfortunately, senior DCA staff also have issued statements that reinforce the incorrect application of DEP regulations and municipal zoning ordinances.
Essentially, code officials and DCA have (apparently) been forcing home owners to raise houses one-foot higher than required by legal regulations.
To date, there is no published information to determine for how many houses such misapplication of regulations has already occurred.
If you are faced with a similar problem, please contact us to provide assistance.