How Tall is a "Story"?

One question that has come up a lot related to the South Willamette Special Area Zone is, how tall, exactly, is a story?  The answer, like many things, is it depends.

The “story” concept is a new one in the SW-SAZ. Under current Eugene code, buildings only have to comply with a height limit—you could have as many floors as you could fit within that height limit. Under the SW-SAZ, buildings would have to comply with both the height limit and the story limit. Buildings in areas designated “3-story”, which has a maximum height of 45 feet, could be a two story building with each story being 15 feet (30 feet total), a three story building with each story being 15 feet (45 feet total), or a three story building with each story being 11 feet tall (33 feet total.)  All of these would be allowed. What would not be allowed is to build a four story building with each story being 11 feet tall—even though at 44 feet, that would be under the height limit, it wouldn’t comply with the story limit. Alternately, you couldn’t build a three story building with one 20 foot story and two 15 foot stories; that would be taller than the height limit.

So how tall is each story going to likely be? Different uses and styles will have stories of different heights. These days, much new residential construction has 9 foot ceilings, though some may still have 8 foot ceilings. Offices are typically have ceiling heights of 9’ to 10’ high. Retail use, particularly on a first floor, frequently will have ceilings a few feet taller, and of course, some specialized uses (like theaters) might have very tall ceilings.  The SW-SAZ calls for the first level of retail to have a 14’ height. Each story will also have some height dedicated to actual floor and ceiling itself as well as space for HVAC and other infrastructure. In residential construction a floor structure can often be about 1 foot deep, which in a building with 9’ ceilings would make a full story about 10’ Because office buildings usually have more stringent requirements for air conditioning ducts, plumbing and wiring systems above the ceiling, in addition to concrete floor slabs, they usually require 18 to 24 inches between the ceiling and next floor level. The exact amount will vary based on the design of the building and the type of materials used—for example insulation that meets higher performance standards will be thicker than lower-performing insulation. But while the “floor to floor” distance may vary, the overall height of the building will be limited by the code.

Higher ceilings are generally considered to be a nice feature in buildings—the trend over the past decade or so in the United States has been to move towards nine foot ceilings as opposed to eight foot ceilings in residential constructions, and of course, high ceilings are frequently listed as a feature in real estate listings. However, there is an atheistic limit to how high a ceiling can be—just as ceilings that are too low make a space feel cramped, ceilings that are too high can result in a space that feels uncomfortably exposed, or out of proportion with the rest of the space. A closet with 15 foot high ceilings would feel like an elevator shaft.

A three story building will most likely be in a range of 33 to 40 feet. A building with 14 foot ceilings heights on the first floor (for retail use) and two floors of residential or office with 9 foot ceilings above would probably be somewhere in the neighborhood of 36 feet tall, give or take a few feet. By comparison, the height allowed for current low-density (R1) residential development, including sloped roofs, is 37 feet. 

The story limit, combined with the height limit, gives architects and developers the flexibility to set ceiling heights that make sense for their buildings and to use more sustainable building materials that may add to the height. Ultimately, the story limit means that even most buildings “built to the max” will be under the maximum allowed height.