The growing public backlash over the City of Portland's push to encourage developers to build dense housing without parking in single-family neighborhoods led me to do a little math.
First, some basic facts. A standard city block is 200 feet long from corner to corner. A 200-foot-long block face with parallel parking and without any fire hydrants, sidewalk extensions ("corner bumps", the little curved bits that project into the street at the corners), truck loading zones, and driveways will accommodate 10 parked cars. A block face with sidewalk extensions will hold 9 parked cars. A block face with sidewalk extensions and four houses with single-width driveways will hold 5 or 6 cars, depending on how the driveways are arranged.
Next, consider the proposed 50-unit project at 30th and SE Hawthorne. The story quotes the developer saying that at a similar project in Northeast Portland, "only 13 to 14 cars parked on the street were attributed to residents of the building." (I think he had in mind the Irvington Garden Apartments at NE 15th and Hancock Street, also a 50-unit project.) Taking that as fact, the Hawthorne Boulevard project's residents will bring 13 or 14 cars to the neighborhood to park on the street. This doesn't count visitors they might have.
How much curb space will the residents' cars require? Likely about 280 to 300 linear feet, or just under a block and a half.
The Hawthorne site itself, however, is only 100 feet square. Half of the Hawthorne frontage is taken up by a curb extension for a bus stop, so the site will contribute only 150 feet of curbfront toward the parking needs of its residents. (The fire hydrant is at the corner and doesn't reduce the available parking.) The project will require another 130 to 150 feet of curbfront for its residents beyond what's in front of the project itself, putting its residents into a parking competition with the condominium (four units) and two houses to the north.
This leads to the question: what is the available common parking supply, and who should get to claim it first? It's a question that the city planners should answer before they burden it with more than it can handle.
