Boulder’s mandatory Inclusionary Housing Policy requires new residential development to create 20 percent affordability in perpetuity. Since 2000 the policy has produced approximately 750 affordable housing units (625 for-sale and 125 rental). The policy applies to residential developments of all sizes, including single-unit properties, but exempts accessory dwelling units (ADUs).

For properties with less than five units, developers meet their obligation by paying a “cash-in-lieu” fee. The per-unit fee rate is considerably lower for properties with less than five units, and lower still for developers of a single home.