Like most cities, Portland requires lots to be at least a certain size to be developed. Standard lots in the older parts of Portland are typically 50 feet wide by 100 feet deep. Lots less than 36 feet wide are considered “narrow” lots. In some neighborhoods, lots were created in 25-foot-wide increments. These are called historically narrow lots. The land was subdivided long ago into twice as many lots as is currently allowed in the R5 zone and they do not meet current minimum lot size or width standards.
In 2003, the City of Portland established a minimum lot size of 3,000 square feet and a minimum width of 36 feet for an R5 lot to be developed. An exception was made for lots smaller or narrower than these dimensions, which can only be developed if they have been vacant for at least five years. In places where historically narrow lots are present, these lots offer another housing type option: smaller lots for smaller houses. Two side by side narrow lots can offer two detached narrow houses, two slightly wider attached houses or two units in a duplex.
On a 15-foot-wide house, a 12-foot-wide garage dominates the front façade, removing opportunities for street facing widows on the ground floor. The area of the garage also increases the size and depth of narrow houses and subtracts from first floor living area. Driveway curb cuts also remove available on-street parking. Under the draft proposal, parking access could be shared, or provided off an alley in the back.