HOW ZONING WORKS .. SETBACKS

Setbacks are the minimum distance your building can be located from the four sides of the property line. Again for our example, see the chart on page 5.3-5. As you can see, set backs are shown for various lot widths. For instance, the side interior lot set back is 5’ if your lot is 41’ to 75’ wide, and so on. Here’s how the setbacks affect you:

1. Setbacks do not apply to an existing house because the house was built before the new zoning code became law. However, the setbacks are in effect for an addition or a new house.
2. The side setbacks are reasonably straight forward. These apply to the primary structure only.
   1. For > 30’, 41’-74’, and <75’ lots, the setbacks are 3’, 5’ and 10’ respectively.
   2. For lots 31’ – 40’, a very common city lot, the two side setbacks have to total 10’, but neither can be less than 3’.
      1. 3’ + 7’ is ok, but 2.5’ + 7.5’ is not.
      2. 5’+5’ is also ok, and so on.
3. The rear setbacks are just as easy except that there are really three different types of setback rules depending on what type of building is in the back yard.
   1. Primary structure – if there is an alley, the setback is 12’. If no alley, the setback is 20’.
   2. Garage in the rear 35% with an alley – 5’
   3. ADU (accessory dwelling unit) in the rear 35% with an alley – 5’. Note that an adu is a new type of structure permitted by the zoning code. See adu section to learn more.
4. Side setbacks for a garage and an adu are 0’ and 5’ respectively.
5. The front setback requires some explanation.
   1. If you have an existing house and you are not adding on the front, the front setback does not apply. If you are adding a new dormer or anything like that, the front setback applies to the new work.
   2. In most city zones, a block sensitive setback is required. The short description is that new improvements cannot extend past the face of adjacent houses. Porches do not count. The survey will show the existing setbacks from the two neighboring houses and we are required to use the adjacent setback furthest from the property line. In most cases this is 20’ to 25’. Since all block sensitive setbacks don’t fall into the above description, Chapter 13, page 13.1-30 has a detailed description on how to determine block sensitive setbacks.

Please let me know if you have any questions regarding the above.

HOW ZONING WORKS .. MINIMUM LOT SIZE

On page 5.3-5, you can see that the various zones show minimum lot sizes. For instance, the U-SU-C zone has a minimum lot size of 5,500 sf, the U-RH-2.5 zone has a minimum lot width of 25’, and so on. Minimum lot size can affect you as follows:

1. If you are adding to an existing house and you already own the lot, there is no effect because the lot size was determined before the new zoning code became law.
2. Minimum lot size has an effect if you want to subdivide an existing lot.
   1. For instance, if you own a 50’ x 125’ lot in a U-SU-B zone, your total lot area is 6,250 sf. If you want to subdivide this lot into two 25’x125’ lots, it’s not permitted because the new lot sizes are below the minimum area of 4,500sf and below the minimum width of 35’.
   2. In the same example, if your 50’x125’ lot was in a U-SU-A zone, the subdivision is permissible. This is because your new lot areas are now 3,125sf, which is above the minimum 3,000 sf and your new lot widths are 25’, which is at the minimum of 25’.

Please let me know if you have any questions regarding the above.

HOW ZONING WORKS .. MAXIMUM LOT COVERAGE

Maximum lot coverage is a ratio of the land covered by the building to the open space on the lot. In our page 5.3-5 example, lots <30’ are permitted 50% coverage and all others are permitted 37.5%. It’s not given a letter or number in the outline, but it occurs just below setbacks.

This sounds pretty innocuous but it really becomes a major determiner of permitted building volume because city lots are fairly small. This information is described in detail on page 13.1-42. Also, there are some key exceptions. Here’s how it works:

1. Calculate the area of the first floor, including exterior walls, the existing building if there is one, and any new structures. This must be done in detail because the plan review engineers will be figuring it in detail as well.
2. Add decks or balconies which overhang, but not roof overhangs.
3. Add the front porch as a separate number.
4. Add the garage and any accessory buildings.
5. We get an exception for the front porch if there is one. A maximum of 400 sf. Subtract that.
6. We get a 50% exception for a detached garage if it’s at least 15’ from the house. Subtract 50% of garage area.
7. Normally, without considering other exceptions and details, we add all the above to see if it comes up to the permitted maximum coverage.
   1. For instance, if our lot is 37.5’ x 100’ = 4,688 sf. Then 37.5% of the total = 1,758sf. A typical house is around 1,000 sf and 50% of a 22×22 garage is 242sf, so we have an available coverage of 1758 – 1000 – 242 = 516sf. In this example, our addition could be 2 ½ stories high and approx. 20×25. It could also be one or two stories high but the coverage could not exceed 20×25 or some other shape with the same area.
   2. The same calculation would apply to a new house.
   3. Obviously, everything in the above is a variable, so if we want to maximize the area of new improvements, we’ll need to try some combinations. However, this maximum coverage is normally more than enough.

Please let me know if you have any questions regarding the above.