San Bruno City Zoning Code
CHAPTER 12
200 DEVELOPMENT REGULATIONS FOR THE R-1 AND R-2 ZONING DISTRICTS
§ 12.200.010 Purpose.
The city of San Bruno is a well-established residential community of predominantly single family homes. Significantly oversized residential structures are incompatible with the character of this residential community, and are not in harmony with the principles of high quality neighborhoods. This chapter is intended to accomplish the following:
A.
Enhance the identity of residential neighborhoods.
B.
Assure provision of light and air to individual residential parcels.
C.
Assure a reasonable level of compatibility in scale of structures within residential neighborhoods.
D.
Establish and preserve spatial relationship(s) between structures, between structures and adjacent streets, and within neighborhoods.
E.
Address residential parking for non-conforming structures seeking extensive expansion or remodeling.
F.
Prohibit the loss of interior housing space through the creation of excessive residential storage or parking garages.
G.
Control development of hillside lots and lands, preserve buildings suited for natural hillside surroundings, and recognize differences between hillside developments and flat land developments.
H.
Preserve the city's dwindling stock of affordable housing.
§ 12.200.020 Definitions.
For the purposes of this chapter, the following definitions shall apply:
is defined as a roofed or unroofed porch, platform or balcony, open on one or more sides, access to which is gained by a door, stairway or other passage.
is defined as the gross floor area of a building, including the garage area, divided by the total lot area of the parcel on which the building is situated.
is defined as the total floor space of all floors of a building or buildings measured to the outside surfaces of the building(s), including, but not limited to, exterior walls, or other external elements of the building envelope system, the attached or detached garage or other designated vehicle storage area, and other accessory buildings on the lot that are greater than one hundred twenty square feet, but excluding non-habitable space as defined herein.
is defined as any enclosed floor area in the house, garage, or accessory building having any potential living space with minimum dimensions of eight feet by ten feet and with at least seven feet of head room.
is defined as enclosed floor area that is not defined as "habitable."
is defined as the total lot area of the parcel upon which a building is situated or proposed, reduced by the development limitations of Section 12.200.040, below.
is defined as that portion of any building included between the surface of any floor and the surface of the next floor above it. If there is no floor above it, the space between such floor and the ceiling shall constitute a story.
is defined as the lowest story in a residence, wherein at least fifty percent of any one wall of that story is four feet above grade.
§ 12.200.030 Development regulations.
Development regulations in the R-1 and R-2 districts are as follows. For the purposes of this section, buildings which are moved or manufactured off-site and placed on a property shall be subject to the same requirements as new construction on infill lots.
A.
Minimum Site Area. Five thousand square feet for interior lots, six thousand square feet for corner lots.
B.
Minimum Lot Area per Dwelling Unit. Two thousand nine hundred square feet in the R-2 district.
C.
Minimum Lot Width. Fifty feet, except sixty feet for corner lots.
D.
Minimum Setbacks.
1.
Front: fifteen feet, except the minimum setback from sidewalk to a garage shall be twenty feet. Where sixty percent or more of the lots in a block have been improved with buildings, the minimum required front yard shall be the average of the front yard of the improved lots if said average is less than the requirements of this article.
2.
Interior side: five feet. On any legal substandard lot that qualifies as a building site pursuant to the provisions of this article, the width of an interior side setback may be reduced to ten percent of the width of the parcel, but in no case to less than three feet.
3.
Street side (corner lot): ten feet. On any legal substandard lot that qualifies as a building site pursuant to the provisions of this article, the width of the street side setback may be reduced to five feet plus ten percent of the width of the parcel, but in no case to less than eight feet.
4.
Rear: ten feet.
E.
Maximum Coverage by Structures. Varies, lot coverage of structures in the R-1 residential districts shall not exceed eighty percent of the total floor area allowed by this section, and structures in the R-2 residential district shall not exceed one hundred percent of the total floor area allowed by this section.
F.
Maximum Coverage by Impervious Surface - Total Lot Area. Eighty percent in the R-1 districts, and eighty-five percent in the R-2 district; when a new dwelling is constructed, or an addition increases the gross floor area, the impervious surface in the front setback area shall be limited to sixty percent.
G.
Maximum Floor Area. The permitted floor area (FA) of buildings shall be determined by multiplying the adjusted lot size (from Chart 1, below) by the floor area ratio corresponding to the slope of the lot (from Chart 2, below).
H.
Average Percent Slope of Site. The average percent slope of a site is computed by the following formula:
AS = (100 x I x L)/A | ||
where: | ||
AS | = | average percent slope of a site |
I | = | contour interval in feet, not to exceed ten feet |
L | = | summation of length of contour lines in feet |
A | = | area in square feet of parcel being considered |
I.
Floor Area Ratio Adjustment Factor For Lot Size. The floor area ratio shall be adjusted inversely proportional to the lot size as shown in Chart 1, below. The floor area shall be further adjusted by the average slope as shown in Chart 2, below.
Chart 1: Adjusted Lot Size | |
|---|---|
Lot Size (sq. ft.) | Adjustment Factor |
2,500 | 1.20 |
3,000 | 1.16 |
3,500 | 1.12 |
4,000 | 1.08 |
4,500 | 1.04 |
5,000 | 1.00 |
5,500 | 0.97 |
6,000 | 0.94 |
6,500 | 0.91 |
7,000 | 0.88 |
7,500 | 0.85 |
8,000 | 0.82 |
8,500 | 0.79 |
9,000 | 0.77 |
9,500 | 0.75 |
10,000 | 0.73 |
10,500 | 0.71 |
11,000 | 0.68 |
11,500 | 0.66 |
12,000 | 0.64 |
12,500 | 0.62 |
13,000 | 0.61 |
13,500 | 0.60 |
14,000 | 0.59 |
14,500 | 0.58 |
15,000 | 0.57 |
15,500 | 0.56 |
16,000 | 0.55 |
16,500 | 0.54 |
17,000 | 0.53 |
17,500 | 0.52 |
18,000 | 0.51 |
18,500 | 0.50 |
19,000 | 0.49 |
19,500 | 0.48 |
20,000 | 0.47 |
>20,000 | 0.47 |
Chart 2: Permitted Floor Area | |
|---|---|
Average Slope (percent) | Floor Area Ratio (FAR) |
<10 | 0.550 |
10 | 0.550 |
11 | 0.545 |
12 | 0.541 |
13 | 0.537 |
14 | 0.533 |
15 | 0.529 |
16 | 0.524 |
17 | 0.519 |
18 | 0.514 |
19 | 0.509 |
20 | 0.505 |
21 | 0.500 |
22 | 0.495 |
23 | 0.490 |
24 | 0.485 |
25 | 0.480 |
26 | 0.475 |
27 | 0.470 |
28 | 0.465 |
29 | 0.460 |
30 | 0.456 |
31 | 0.451 |
32 | 0.446 |
33 | 0.441 |
34 | 0.436 |
35 | 0.432 |
36 | 0.427 |
37 | 0.422 |
38 | 0.417 |
39 | 0.412 |
40 | 0.407 |
41 | 0.402 |
42 | 0.397 |
43 | 0.392 |
44 | 0.387 |
45 | 0.383 |
>45 | 0.383 |
 |
The above displays graphically the application of Chart 1 and Chart 2. The horizontal axis is the total lot size. The vertical axis is the floor area of the building. The curve shows the maximum floor area allowed, each curve representing a different average slope. The above is provided for illustrative purposes only, and Chart 1 and Chart 2 are to be applied.
J.
Building Heights. The maximum height of structures, which for the purposes of this chapter only shall mean the vertical distance from the elevation of the sidewalk in front of the house at the midpoint of the horizontal width of the house to the highest or topmost point of the roof, shall not exceed the following limits:
1.
A height of twenty-eight feet for lots with an average slope of less than twenty percent from front property line to rear property line, as well as for lots which slope from side yard to side yard regardless of the average slope; or
2.
A height of twenty-six feet for downsloping lots (from front to rear) with an average slope of twenty percent or more; or
3.
A height of thirty feet for upsloping lots (from front to rear) with an average slope of twenty percent or more.
K.
Second Story Front Decks. Second story front decks may be no larger than seventy-two square feet and shall have a front depth less than six feet. Second story front decks shall be set back at least eighteen inches from the face of the first floor of the house, or provide a solid vertical surface around the bottom eighteen inches of the deck.
L.
Second Story Privacy. Transparent second story windows, any other transparent opening, or any deck facing any interior side yard adjacent to an abutting property which abutting property has a side yard greater than ten feet, shall not be allowed.
M.
Third Stories. Third stories, where any part of the three stories lie within the same vertical plane are not allowed. This provision applies whether the third story is created for a new home or for an addition to an existing home.
O.
All exterior changes to a single-family or two-family residence requiring a building permit shall be consistent with the basic design principles of the residential design guidelines, as adopted by the city council and amended from time to time.
Q.
Architectural Review Permit. As set forth in Section 12.200.040.
§ 12.200.040 Architectural review permits required.
Approval of an architectural review permit by the community development director is required for the following project types in the R-1 or R-2 districts, as set forth in Chapter 12.108:
A.
New structures or additions to existing structures that encroach into a side or rear setback by up to two feet beyond what is permitted by Section 12.200.030(D), except that in no case shall less than a three-foot setback be allowed. Encroachments into side or rear setbacks greater than two feet beyond what is permitted by Section 12.200.030(D) shall require approval of the planning commission.
B.
New structures or additions to existing structures that cause the lot coverage to exceed the percentage defined in Section 12.200.030(E), but not to exceed one-hundred and ten percent of the total floor area allowed by this section. Projects that result in lot coverage greater than one-hundred and ten percent of the total floor area allowed by this section shall require approval of the planning commission.
C.
The addition of impervious surface that exceeds the percentage defined in Section 12.200.030(F). Exceeding allowed impervious surface by ten percent or greater shall require approval of the planning commission.
D.
New structures or additions to existing structures that cause the floor area to exceed the permitted floor area defined in Section 12.200.040.G, H, and I, but not to exceed a floor area ratio equivalent of 0.62 allowed by this section. Projects that result in equivalent floor area ratio above 0.62 shall require approval of the planning commission.
E.
New structures or additions to existing structures with building heights that exceed the allowed heights in Section 12.200.030(J) by up to three feet. Projects that exceed allowed heights by more than three feet shall require planning commission approval.
F.
New or modified second story front decks that exceed the allowances defined in Section 12.200.030(K).
G.
New or modified second story windows, openings or decks that do not comply with Section 12.200.030(L).
H.
New or modified third stories, where any part of the three stories lie within the same vertical plane as defined in Section 12.200.030(M). This provision applies whether the third story is created for a new home or for an addition to an existing home.