How big can a detached garage or shed be in Novi?

It depends on your zoning district, and the cap counts your garage, shed, and every other accessory building together (Section 4.19.1.E):

| District | Aggregate accessory floor area | | --- | --- | | R-3, R-4, RT | 850 sq ft | | R-2 | 1,000 sq ft | | RA and R-1 | 1,500 sq ft |

An R-1 lot that does not meet the district's area and width minimums is held to 1,000 square feet. One universal cap overrides the table in every district: in no instance may the aggregate of all accessory buildings exceed the ground floor area of the principal building on the lot (Section 4.19.1.E.v), so a small house allows less accessory space than the district figure suggests. In RA and R-1 there is one escape hatch: on a lot of at least 1 acre that is deed-restricted from future division, the aggregate may exceed the house's ground floor area, up to 2,500 square feet (Section 4.19.1.E.v).

Two more caps apply. All accessory buildings together may cover at most 25 percent of your required rear yard (Section 4.19.1.C), and the number of detached accessory buildings is limited to one on lots under 21,780 square feet, two on larger lots (Section 4.19.1.J). Any accessory building over 200 square feet must be architecturally compatible with the house, with a minimum 3/12 roof pitch (Section 4.19.1.L).