Can I build a duplex in Canton Township?

Rarely, and never by right on an ordinary subdivision lot. The single-family articles expressly prohibit multiple-family use in R-1 through R-5 (Section 11.01), and two-family dwellings appear in exactly one use list: they are a special land use in the R-6 single-family attached district, on lots at least 80 feet wide and 120 feet deep (Section 12.02.B.3).

Adjacent possibilities:

• 2-unit attached condominiums have dimensional rows in the R-2 through R-5 schedule, but only for projects approved as a special land use, and single-family attached development in those districts needs a site of at least 5 acres outside any platted subdivision (Section 26.02, footnote n; Section 6.03.F).
• Townhouses and duplex forms are permitted by right in R-6 and MR as part of attached housing developments meeting the Section 6.03.A site standards, with 5,400 to 7,600 square feet of land per unit (Section 26.02, footnote c).
• Interestingly, the site plan article exempts a two-family dwelling in the R-5 district from site plan review (Section 27.02.B.2), while no R-5 use list authorizes one; that residue of an older text should not be read as permission.

So the realistic paths are an R-6 parcel plus special land use approval, a 5 acre attached-housing site, or a rezoning. Ask Planning Services at 734-394-5170 what the future land use map supports before designing.