Portland’s Historic Zoning Change Allows More than Single Family Homes

In Portland we helped City Planners and City Commissioners jump start more affordable housing options by modeling and analyzing zoning code changes.

To inform an affordable housing policy in the single-dwelling zones update, various small development prototypes were modeled using Small Development Counts proforma-based planning approach.

This approach explores the physical and financial implications of allowing additional zoning capacity as part of a ‘Deeper Affordability’ amendment to Portland’s single-dwelling zoning code update.

The Affordable 6-plex Pro forma Summary models for-sale units in a 6-plex in Portland’s single-dwelling zones affordable to a 3-person household earning 80% of area median income ($79,110 per year in 2019). The inputs used were vetted by a cadre of affordable housing providers and assume development in a high-opportunity inner neighborhood. Allowing the density bonus for affordable housing providers levels the playing field with market rate developers by allowing them to compete for the same pieces of land without getting outbid.

This approach to modeling outcomes to inform policy demonstrated how policy levers can be adjusted that result in small development as affordable housing that costs the community nothing but also results in limited affordable housing dollars either being stretched further or used to push to deeper levels of affordability.