How much of my lot can buildings cover in Troy, Michigan?

30%. All of Troy's R-1 one-family districts cap lot coverage at 30% (Section 4.06.C). The limit is the same from R-1A through R-1E.

Related caps to keep in mind:

• Rear yard. Detached accessory buildings may not occupy more than 25% of the required rear yard (Section 7.03.B.2.b), so a large garage can hit that cap before the 30% overall limit.
• Multiple-family. The MF district allows 35% coverage (Section 4.08.C).

For a typical project, add up the footprints of the house, attached garage, and any detached buildings and compare against 30% of the lot area. Exactly which structures count toward coverage on your lot is a staff question, so confirm the calculation with the Planning Department at 248-524-3364 before finalizing plans. Exceeding the cap requires a dimensional variance (Section 15.04.E).