Setbacks are the minimum distance required between a specified object and another point, usually lot lines. They're typically specified in the zoning to maintain distances between buildings, minimizing the bulk of buildings and maintaining any desired open space between them.
Setbacks typically vary based on the type of lot line (ie., front, side, rear), the type of lot (ie., corner, thru, interior), or any lot adjacencies (ie., abutting residential, across the street from commercial, etc.).
Here you can see all the setbacks applied on UrbanForm's web zoning map. Yes, UrbanForm knows what all the setback rules are, and has applied them to the site for you, so you can see them instantly. Both graphically and in detailed text. With source links to verify.
There's no software to download, no trial to sign up for. It's actually free for anybody.
The dark solid lines are the property lines; the dashed lines are the setback lines, and you can see them for any site in the entire city.
You'll notice UrbanForm takes into account the lot type, adjacencies that may modify setbacks, and any other contingency found in the zoning code.
Once you realize the setbacks are in place; the rest of the zoning is unlocked--because you can't truly understand maximum buildable area without knowing the amount of ground you're allowed to build on (we give you that with our MaxBuild statistics).
We do this so that building professionals can instantly assess the zoning regulations that may apply to a site. Verifying and gaining consensus quickly. Allowing them to move faster toward design and problem-solving.
It's faster feasibility. Faster assessment. Faster let's get to designing something great, not just compliant.
For better buildings, cities, and environments :)