Work on the proposed construction or development shall begin within
180 days after the date of permit issuance or the permit shall expire
unless a time extension is granted, in writing, by the floodplain
administrator. Time extensions shall be granted only if a written
request is submitted by the applicant, which sets forth sufficient
and reasonable cause for the floodplain administrator to approve such
a request. The "actual start of construction" means either the first
placement of permanent construction of a structure on a site, such
as the pouring of slab or footings, the installation of piles, the
construction of columns, or any work beyond the stage of excavation,
or the placement of a manufactured home on a foundation. Permanent
construction does not include land preparation, such as clearing,
grading, and filling; nor does it include the installation of streets
and/or walkways; nor does it include excavation for a basement, footings,
piers or foundations or the erection of temporary forms; nor does
it include the installation on the property of accessory buildings,
such as garages or sheds not occupied as dwelling units or not part
of the main structure. For a substantial improvement, the "actual
start of construction" means the first, alteration of any wall, ceiling,
floor, or other structural part of a building, whether or not that
alteration affects the external dimensions of the building.