Eugene, I’m not sure if this agrees with the zoning depts but for CA, I consider a measure of “density” as follows:
1 AC+ per unit (rural, semi-rural [even if located “suburban”])
.25 AC to 1 AC per unit (semi-rural, suburban or urban low density)
5000 sf to .25 AC per unit (suburban to urban mid density)
<5000 sf (for an SFR) exurban, suburban and urban high density (patio homes, PUD's, zero lot line, etc)
<=8 units on +/- 5000 sf lot (exurban, suburban or urban) mid density multifamily
8-12 units on +/- 5000 sf lot (exurban, suburban or urban) high density multifamily
13+ units on +/- 10,000 sf lot (incl mid rise/high rise bldgs) high density urban multifamily
