Building line The legal boundary marking where a property's structure or lot meets the public sidewalk, forming one edge of the sidewalk's paved width.
This line matters for sidewalk repair because DOT's transverse slope specification is measured starting from the building line and running toward the curb, so an improperly graded flag near this edge can trigger a drainage-related violation even without visible cracking. It's also the reference point for areaways, cellar doors, and other below-grade features that sit right at the edge of a building's foundation. Surveyors and contractors use the building line, together with the curb line, to establish the exact footprint a sidewalk reconstruction needs to cover.
Frequently Asked Questions About Building line
What is the building line?
The legal boundary where a property's structure or lot meets the public sidewalk, forming the inner edge of the sidewalk's paved width.
Why does it matter for repair?
DOT's transverse slope is measured from the building line toward the curb, so a flag graded incorrectly at this edge can be cited for drainage even without visible cracking.
What features sit at the building line?
Areaways, cellar doors, stoops and other below-grade or projecting elements at the edge of a building's foundation.
Is the building line the same as the property line?
Not always. They can differ on older or irregular lots, which is why a survey sometimes matters.