The purpose of this chapter is to explain how various measurements referenced in this zoning code are to be calculated.
(Ord. 1598)
For all calculations, the applicant shall be responsible for supplying drawings illustrating the measurements that apply to a project. These drawings shall be drawn to scale and of sufficient detail to allow easy verification upon inspection by the director.
(Ord. 1598)
When calculations result in fractions, the results will be rounded as follows:
A.
General Rounding. Fractions of 0.5 or greater shall be rounded up to the nearest whole number and fractions of less than 0.5 shall be rounded down to the nearest whole number, except as otherwise provided.
B.
Density Rounding. For purposes of computing the maximum number of residential units allowed on a lot, any fraction shall be rounded down to the nearest whole number.
C.
Rounding for State Affordable Housing Density Bonus. For projects eligible for bonus density pursuant to Government Code Section 65915 or any successor statute, and Chapter 11.4.55: Affordable Housing Bonus, any fractional number of permitted bonus density units shall be rounded up to the next whole number. See Chapter 11.4.55: Affordable Housing Bonus, Section 11.4.55.01.C: Calculation of Density Bonuses.
(Ord. 1598)
A.
Measurements are Shortest Distance. When measuring a required distance, such as the minimum distance between a structure and a lot line, the measurement is made at the closest or shortest distance between the two objects. See Figure 11.1.15.020.A: Shortest Distance.
Figure 11.1.15.020.A Shortest Distance  |
B.
Distances are Measured Horizontally. When determining distances for setbacks and structure dimensions, all distances are measured along a horizontal plane from the appropriate line, edge of building, structure, storage area, parking area, or other object. These distances are not measured by following the topography or slope of the land. See Figure 11.1.15.020.B: Horizontal Measurement.
Figure 11.1.15.020.B Horizontal Measurement  |
C.
Measurements Involving a Structure. Measurements involving a structure are made to the closest wall of the structure. Chimneys, eaves, cornices, and bay windows up to 12 feet in length are not included in the measurement. Other features, such as covered porches and entrances, are included in the measurement. Structures or portions of structures that are entirely underground are included in measuring required distances. See Figure 11.1.15.020.C.1: Measurements Involving a Structure, and Figure 11.1.15.020.C.2: Architectural Projections into Setbacks.
Figure 11.1.15.020.C.1 Measurements Involving a Structure  |
Figure 11.1.15.020.C.2 Architectural Projections into Setbacks  |
(Ord. 1598; Ord. 1611)
A.
General. The height of a structure shall be measured vertically from the average level of the highest and lowest finished grade of the ground covered by the structure to the highest point of the structure or to the peak of a gable, pitched, mansard or hipped roof or to the finished roofline of a flat roof or top of a parapet required by California Building Code.
1.
Exceptions for Accessory Building Features. The following listed building features may be erected to a maximum height as follows:
2.
Exception for Surfside. Maximum building height for residential structures, including accessory dwelling units, shall be measured pursuant to Section 11.2.05.015.A.3: Building Height Limit.
B.
Measuring the Height of Buildings Located Near Retaining Walls. If any portion of a building lies within 5 horizontal feet of an above-ground retaining wall, and the base of the retaining wall is at a lower elevation than the building, the height of the building shall be calculated from the base of the retaining wall (at the lower of natural or finished grade) rather than from the base of the building wall. See Figure 11.1.15.025.B: Measuring the Height of Buildings Near Retaining Walls.
Figure 11.1.15.025.B Measuring the Height of Buildings Near Retaining Walls  |
C.
Measurement of Fence or Wall Height.
1.
Determination of Height. The height at the property line shall be measured from the owner's side of the fence or wall. A joint fence or wall on the property line may be measured from either side of the fence or wall. In the case of a joint fence or wall where there is a difference in the ground level between 2 adjoining parcels of less than 2 feet, the height of a fence or wall constructed along the property line shall be determined by using the finished grade at the base of the fence or wall on the highest parcel.
Figure 11.1.15.025.C Determination of Property Line Fence Height  |
D.
Measuring the Height of Combined Fences and Retaining Walls. When a fence is constructed on top of or within 1 foot of the face of an above-ground retaining wall greater than 2 feet in height, and located in a required yard, the height of the fence shall be measured from the top of the fence to the midpoint height of the retaining wall, excluding the uppermost 2 feet of the retaining wall.
Figure 11.1.15.025.D Fences on Top of Retaining Walls  |
E.
Measuring the Height of Decks. Deck height is measured from grade to the top of the floor of the deck if there is no rail or if the rail walls are more than 50% open, and from the ground to the top of the rails for all other situations.
(Ord. 1598; Ord. 1699; Ord. 1721, 11/10/2025)
A.
Lot Width. Lot width is the mean of the distances between the side lot lines as drawn at right angles to the lot depth line at points 20 feet from its front and back.
B.
Lot Depth. Lot depth is measured along an imaginary straight line drawn from the midpoint of the front property line of the lot to the midpoint of the rear property line. Where no lot line is within 45 degrees of being parallel to the front lot line, a line 10 feet in length within the lot, parallel to and at the maximum possible distance from the front lot line, will be deemed the rear lot line for the purpose of establishing setbacks and measuring rear yard depth. Refer also to Section 11.6.05.010: Definitions of Specialized Terms and Phrases; Lot Line Types: Rear Lot Line, and Figure 11.6.05.010.L.5: Irregular Lots: Determining Rear Lot Line.
Figure 11.1.15.030 Measuring Lot Width and Depth  |
(Ord. 1598)
A.
Existing Trees. Existing trees are measured at a height of 4.5 feet above the ground. Trees on slopes are measured from the ground level on the lower side of the tree. If a tree splits into multiple trunks below 4.5 feet, the trunk's diameter is measured at its most narrow point below the split.
B.
New Trees. New trees are measured in caliper inches, which is the diameter of the trunk 6 inches above the ground.
(Ord. 1598)
A.
Average Front Setback Determination. Average front setback is determined by the following calculations.
1.
Determine Required Setback Area. The required average front setback is determined by multiplying the required minimum setback depth, 12 feet, by the frontage of the lot, minus the width of the required minimum side yard setbacks.
Sample calculations are provided below.
2.
Determine Ground Level Setback Area. The ground level setback area is calculated by summing the areas of each area of change of building articulation between the required side yard setback lines. Refer to Figure 11.1.15.040.A: Determination of Average Front Setback Area.
3.
Determine Second Level Setback Area. The second level setback area is calculated by summing the areas of each area of change of building articulation between the required side yard setback lines.
4.
Confirm Required Setback Area. The required setback area is confirmed if the sum of the ground level and second level setback areas equal or exceed the required setback area.
B.
Exclusions for Measurements. Unenclosed porches, balconies and decks are not part of the habitable area of the residence and are included as allowable setback area.
C.
Maximum Depth to Wall Face. Any portion of a residence setback more than 20 feet shall be considered to be set back 20 feet for the purpose of calculating the average front setback.
Figure 11.1.15.040.A Determination of Average Front Setback Area  |
(Ord. 1598)
Floor area is the horizontal area (expressed in square feet) of all floors included within a building or buildings, according to the following rules:
A.
Included in Floor Area. Floor area includes:
1.
The floor of atrium and lobby areas;
2.
Enclosed and roofed storage and equipment spaces;
3.
Enclosed and roofed halls, stairways, and elevator shafts;
4.
Enclosed and roofed porches and balconies;
5.
Portions of basements and attics that meet California Building Code (per Title 9, Chapter 9.60: Building Code of the Seal Beach Municipal Code) height requirements for living space (any area where the wall height is 5 feet or greater is counted as floor area). See Figure 11.1.15.045.A: Floor Area Under Sloping Roof;
6.
The actual floor space of mezzanines, interior balconies, and lofts.
B.
Excluded from Floor Area. Floor area does not include:
1.
Garages, carports, or other areas used for parking and loading, or vehicular access to parking and loading spaces;
2.
Unenclosed balconies, decks, porches, and stairs;
4.
The area within a building adjacent to, and in an imaginary horizontal plane with, interior balconies, mezzanines, or lofts.
Figure 11.1.15.045.A Floor Area Under Sloping Roof  |
(Ord. 1598)
Floor area ratio (FAR) is the ratio of the floor area of all principal and accessory buildings on a lot to the lot area. To calculate FAR, floor area is divided by lot area, and typically expressed as a decimal. For example, if the floor area of all buildings on a lot totals 20,000 square feet, and the lot area is 10,000 square feet, the FAR is expressed as 2.0.
(Ord. 1598)
Lot coverage is the ratio of the footprint of all structures on a lot to the lot area, typically expressed as a percentage. The footprints of all principal and accessory structures, including garages, carports, and roofed porches, shall be summed in order to calculate lot coverage. See also Section 11.4.05.100: Residential Accessory Uses and Structures. The following structures shall be excluded from the calculation:
A.
Unenclosed and unroofed decks, porches, landings, balconies, and stairways less than 6 feet in height;
B.
Eaves and roof overhangs projecting up to 4 feet from a wall;
C.
Trellises, gazebos, patio covers and similar structures that have over 50% of the perimeter and roofs open;
D.
Swimming pools and hot tubs that are not enclosed in roofed structures or decks over 6 feet high;
E.
Non-habitable accessory structures that do not require a building permit.
(Ord. 1598)
The width of a garage is not limited to the garage door, but is considered the width of that portion of a building façade that is backed by a garage space. It is measured along the entire length of any enclosing walls that lie perpendicular to the garage door or entry.
(Ord. 1598)
Sign height is measured in the same method as other structures. See Section 11.1.15.025: Measuring Height. Calculation of sign area is described in Chapter 11.4.25: Sign Regulations, Section 11.4.25.040.A: Calculation of Sign Area.
(Ord. 1598)