ALT-1 vs. ALT-2 Filings in NYC: Which Permit Application Does Your Renovation Need?
One of the most common questions we hear from property owners starting a renovation is simple: "Do I need an ALT-1 or an ALT-2 permit?" The answer affects your timeline, your budget, and how your project moves through the Department of Buildings — so it's worth understanding before you finalize plans, not after you've filed.
The Short Version
ALT-1: Required when your project changes the use, egress, or occupancy of a building — even partially. Common triggers: adding a unit, converting a basement to habitable space, combining or subdividing apartments, or any structural work that affects how people exit the building in an emergency.
ALT-2: Covers everything else — renovations that don't change use, egress, or occupancy. Most kitchen and bathroom remodels, interior layout changes, and like-for-like system upgrades fall here.
Why the Distinction Matters
ALT-1 filings trigger a more involved DOB review because they touch life-safety systems. That typically means:
A longer plan review timeline
Coordination with the Department of Buildings' Technical Affairs division in some cases
Additional drawings covering egress paths and occupancy classification
In many cases, a new or amended Certificate of Occupancy at the end of the project
ALT-2 filings move faster because the scope is narrower — but "faster" doesn't mean "no review." Mechanical, electrical, and plumbing changes still need to meet current code, and any structural work still requires sign-off.
A Mistake We See Often
Owners sometimes file ALT-2 for a project that should have been ALT-1 — usually because a "minor" change (like converting a den into a bedroom, or finishing a cellar) technically alters occupancy or egress requirements without the owner realizing it. When DOB catches the mismatch during plan review or a site inspection, the result is a stop-work order, a refiling, and weeks of delay that could have been avoided with the right classification from day one.
How We Approach It
Before we draft a single page of a filing set, we classify the project correctly against DOB's current rules — not against what worked on a similar project a few years ago, since code interpretations and DOB bulletins do shift. This single decision, made correctly at the start, is one of the biggest factors in whether a project's permitting timeline runs smoothly or stalls.
If you're planning a renovation and aren't sure which filing type applies, it's worth a conversation before you commit to a design — the answer can change what's actually feasible within your timeline and budget.
