Everything depends on the city, but in my experience it's de novo. Code changes every 3 years (usually pretty minor stuff). Additionally every site has unique f

Everything depends on the city, but in my experience it's de novo. Code changes every 3 years (usually pretty minor stuff). Additionally every site has unique features. Different shape, different elevations, different neighbors, different soils, etc so some rework of the plans is always necessary to accommodate those differences.