Excavation/Underpinning — Adjoining Property (BC 3309)
NYC Building Code §§ BC 3304, BC 3309 (incl. 3304.3.2, 3309.4, 3309.4.1)
NYC Building Code Chapter 33 governs soil and foundation work, excavation, and underpinning to safeguard the public and adjoining structures. Under BC 3309.4, the person causing soil or foundation work must, at their own expense, preserve and protect adjoining structures (including footings and foundations) from damage, and BC 3309.4.1 requires underpinning or other support of the adjoining structure when its foundation level is at or above the bottom of the new excavation. Separately, BC 3304.3.2 requires written notice to adjoining-property owners not less than 10 days before excavations of 5 to 10 feet within 10 feet of an adjacent footing/foundation, or any excavation deeper than 10 feet.
Who must comply
Other DOB regulations
Special Inspectors & Special Inspection Agencies
1 RCNY § 101-06
OTCR Material Approval
1 RCNY § 101-12
ADA Title III (2010 Standards)
Americans with Disabilities Act Title III, 42 U.S.C. § 12181 et seq.; 28 C.F.R. Part 36 (2010 ADA Standards for Accessible Design)
LL157 Natural Gas Detectors
Local Law 157 of 2016, as amended by Local Law 102 of 2025 (Int. 1281-2025); NYC Admin. Code §28-315.2.4 / §27-2045 — natural gas detecting devices
Office Sprinkler Retrofit (LL26/2004)
Local Law 26 of 2004 (amending NYC Administrative Code / NYC Building Code)
LL26/04 High-Rise Office Sprinklers
Local Law 26 of 2004 (NYC Admin. Code 28-315.2 et seq.)
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