Skip to Main Content View Text-Only

The City of Portland, Oregon

Planning and Sustainability

Innovation. Collaboration. Practical Solutions.

Phone: 503-823-7700

Curbside Hotline: 503-823-7202

1900 SW 4th Ave, Suite 7100, Portland, OR 97201

More Contact Info

Subscribe to RSS feed

Most Recent

View Less

What is “floor area ratio” or FAR?

Floor area ratio measures the square footage of a building on each floor and compares that to the size of the lot. For example, a two-story house that is 1,250 feet on both the first and second floor has a total of 2,500 square feet of floor area. If this house were on a 10,000 square foot lot, it would have a floor area-to-site area ratio of 0.25:1 (10,000 ÷ 2,500 = 0.25). If this same size house were on a 5,000 square foot lot, it would have floor-area-to-site area ratio of 0.5:1 (5,000 ÷ 2,500 = 0.5)

The proposed FAR tool would control the visible bulk of a house while providing flexibility in house design. Most of the floor area of covered and enclosed areas within a house are included. A basement would not count toward a house’s FAR because the majority of a basement’s bulk is below ground. Similarly, only attic space that significantly contributes to a building’s visible bulk would be counted toward a house’s FAR.

Because FAR is intended to reduce the bulk of the primary house, internal garages, internal accessory dwelling units and enclosed porches that contribute bulk would be counted toward a house’s FAR. However, when such features are detached from the primary house and located elsewhere onsite — thereby reducing the bulk of the primary house by distributing it over the whole lot — these detached structures would not count toward a house’s FAR (but would be subject to other size restrictions).