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DOB is not a single yes-or-no question. The filing path depends on the work, the building, the professionals involved, and what the existing conditions reveal.
A useful starting point
01
Cosmetic work and work that changes plumbing, electrical, HVAC, fire protection, structure, occupancy, or the building envelope may have different filing implications. The answer depends on the specific scope and building, not the label “renovation.”
02
Alt-1 generally covers major alterations, including changes in use, occupancy, or egress. Alt-2 generally covers multiple types of work without a change in use, occupancy, or egress. Alt-3 generally covers a minor alteration or limited interior work. Alt-CO refers to a change-of-occupancy path. An LAA, or Limited Alteration Application, is used for qualifying minor plumbing or gas work. The correct classification and filing path require a licensed design professional and/or DOB determination; Corniel does not determine it independently.
03
The owner engages the project team; the architect or engineer of record prepares the professional design and filing documents within their scope; an expeditor manages filing logistics, tracks approvals, and coordinates documentation; and the contractor builds to the approved documents and coordinates field execution. Expeditors manage filings and approvals but do not design or build.
04
A Certificate of Occupancy states the legal use and occupancy type of a building. A Temporary Certificate of Occupancy may allow occupancy while outstanding items remain before a final CO. Occupancy or use changes require the applicable licensed professionals and agency review.
05
Inspections and sign-offs are part of the work, not an afterthought. Closeout documentation, including a Letter of Completion where applicable, matters for future resale and for releasing security deposits where applicable.
06
Townhouse work often involves additional DOB coordination and, depending on the property, additional review. The architect, engineer, building or agency, and project team should establish the applicable path before the scope is committed.
07
We help coordinate alteration agreement requirements and DOB-related filings through licensed professionals when required. Final approvals remain with the building, board, or applicable agency.
AI-generated illustration. Not a completed Corniel project.
Questions worth asking
A licensed design professional and/or DOB determines the applicable filing path based on scope, existing conditions, and the property. Corniel does not determine the classification independently.
Not every scope has the same filing implications. Changes to structure, systems, use, occupancy, egress, or other regulated conditions require project-specific review.
Ready to make the filing path specific?
Share the property, the work you are considering, and the documents already available. The first step is clarifying which questions belong with the licensed project team and the building.
Corniel Construction
Manhattan renovation guidance
Rules-based prototype · not production-approved
