Project Categories: Alterations - 1- and 2-Family Buildings

Residential one- and two-family dwellings are Zoning Use Group 1 or 2, and Occupancy Classification R-3. These buildings are for shelter and sleeping accommodations on a long-term basis (30 days or more at a time) and can include, group homes, convents and monasteries with fewer than 20 occupants, and similar residences.

One and two-family dwellings may be constructed as a detached, semi-detached or an attached building. Per the New York City Zoning Resolution (ZR), a detached building is a ‘freestanding building that is not abutting any other building and where all sides of the building are surrounded by yards or open areas within the zoning lot.’ A semi-detached building is a ‘building that abuts or shares a wall, on a side lot line, with another building on an adjoining zoning lot and where the remaining sides of the building are surrounded by open areas or street lines.’ An attached building is when it ‘abuts two side lot lines or is one of a row of abutting buildings.’

A residential building may include accessory uses associated with the building such as a home occupation, parking, storage, and/or amenities such as a swimming pool, detached garage, etc. Residential buildings may also include incidental uses which are ancillary functions associated with a given occupancy such as mechanical rooms and/or laundry rooms of a certain size that carry a different level of risk than the main occupancy.

Types of alteration work may include any combination of the following:

  • Vertical and Horizontal Enlargements - An addition to the floor area in an existing building.

  • Conversions – A change of an existing use or a new use as defined by the Zoning Resolution, and/or a change in the occupancy classification as defined in the NYC Building Code (BC) in an area not previously used for such purpose.

  • Egress Modifications – Any substantive change in the exiting width, length of travel distance, exit locations, or occupancy load of the building impacting the exits, or any change in number of required exits in a building. Please note one and two family homes only require one means of egress per BC 1021.2

  • Floor Area Reductions – A reduction to an existing building’s floor area that impacts the Certificate of Occupancy; for example, the complete elimination of one or more stories from a building.

Alteration work always results in the issuance of a new or amended Certificate of Occupancy (CO) and may include horizontal and vertical enlargements as well as changes to the building’s egress, zoning use group, and/or building code occupancy classification. Minor enlargements of one and two family homes that do not add or eliminate any rooms or change the number of floors as indicated on the existing CO are considered Renovation projects. An Alteration Project shall not be filed as a Renovation Project.

Alteration work could include other work in the scope which is better described under the various Renovation Project Guidelines or building systems such as new or modified plumbing, HVAC, or gas systems that are better described under the various Building Systems Installation & Modification Guidelines.

Project Categories:

  1. Building Systems Installation & Modifications

  2. Renovations

  3. Construction Equipment

  4. Alterations

  5. Demolition COMING SOON!

  6. New Buildings COMING SOON!

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