501 Knickerbocker Avenue

Buildings with gas piping (except one- and two-family homes) need a periodic gas piping inspection by a licensed master plumber every four years. Community district 4 is on the 2026 cycle; certification is filed with DOB after the inspection. Buildings with no gas piping file a certification instead. Agency page

If the building has a parapet facing a street, sidewalk or other public way, a competent person (such as a mason, engineer or architect) must observe it every year and the owner keeps the report for DOB on request. Detached one- and two-family homes are exempt. Agency page

Buildings over 25,000 sq ft (this lot shows 33,600 sq ft) report energy and water use for the prior calendar year through ENERGY STAR Portfolio Manager. The city's Covered Buildings List is the final word on which buildings must file. Agency page

Covered buildings file an annual greenhouse gas emissions report certified by a registered design professional. Buildings over their emissions limit owe penalties, so it pays to check early. Agency page

Boilers are inspected each calendar year and the report is filed in DOB NOW: Safety within 14 days of the inspection (low-pressure boilers in residential buildings of 5 or fewer families are exempt). Latest report on record: 2026-08-03 (Accepted). Agency page