The short answer: almost always yes
Sidewalk repair work touches the public right-of-way, which means almost every Nassau municipality requires a permit before work begins. Permit fees range from $50 (smaller villages) to $250 (Garden City, Manhasset, Great Neck).
The exception is interior-property hardscape (a backyard walkway, a patio) — that doesn't need a sidewalk permit because it isn't in the public right-of-way.
The Nassau village landscape
Nassau has more incorporated villages than any other New York county outside of NYC. The Town of Hempstead alone contains 22 incorporated villages, each with its own building department. The Town of North Hempstead has another 30+. Every one of them issues sidewalk permits independently.
What this means in practice: a sidewalk repair on Stewart Avenue in Garden City uses a different permit, different fee, and different inspector than a sidewalk repair half a mile away in an unincorporated Hempstead Town area.
What permits typically cost
Town of Hempstead (unincorporated): $75–$125. Garden City Village: $175–$250. Village of Floral Park: $100–$175. Village of Rockville Centre: $150–$225. Village of Mineola: $100–$150. Town of Oyster Bay (unincorporated): $100–$150. Village of Great Neck: $200–$250.
Some villages also require a contractor surety bond on file ($1,000–$5,000) before any permit will be issued. We carry bonds in every village we regularly serve.
What an inspection looks for
Slope (typically 2% cross-slope, no more than 5% running slope), surface tolerance, joint placement, mix strength (4,000 psi minimum in most Nassau villages), and detectable warning panels at curb cuts on commercial properties.
A repair that doesn't pass inspection gets a re-inspection notice and a deadline to correct. Repeated failures can result in a stop-work order and additional fines.
Skipping the permit
Don't. If you skip the permit and a neighbor or inspector reports the work, you'll typically face a fine of 2–4× the original permit fee, a stop-work order, and a requirement to apply for the permit retroactively. The repair may also need to be opened up and re-inspected at your expense.