Code: Dormer (roof and exterior building part)
Description: (Dormer) is a small structure that sticks out from a sloped roof, usually with a window, to create more headroom and light in an attic or top floor. It changes the shape of the roof and exterior wall, so it is treated as part of the building’s structure and exterior by DOB and zoning rules.
Practical Meaning: For a NYC homeowner, adding or changing a dormer is usually not a “small repair” — it often counts as enlarging the building or changing the exterior, so you normally need stamped plans, DOB permits, and sometimes zoning review. Unpermitted dormers or dormers built against code (for example, wrong size, too close to the edge, poor fire rating, or unsafe escape window) can lead to DOB objections, permit problems, or violations.
Where You May See It: You may see the word “dormer” in an architect’s drawings, in zoning or plan review comments, in permit applications for attic conversions or roof enlargements, in DOB objections, or in violation descriptions about illegal attic apartments, roof enlargements, or unsafe exterior conditions.
Why It Matters: Dormers can make an attic more useful, but if they are built without permits or against code they can cause serious problems, including violations, stop work orders, and trouble when you try to sell or refinance. They can also affect fire safety, emergency escape, structural loads, and zoning limits on height and bulk, so they must be designed and approved correctly from the start.
Source: More About Dormers in NYC Roofs