Maximum Residential Lot Coverage Standards in the City of Mesa

In the City of Mesa, the maximum allowable lot coverage for residential properties is determined by the specific zoning district, ranging from as low as 15% in Agricultural areas to as high as 80% in certain Small Lot Single Residence districts. Most standard Single Residence (RS) districts permit between 40% and 60% coverage, while Multiple Residence (RM) districts typically allow up to 70% of the lot to be covered. These measurements generally account for all structures with roofs, including primary dwellings, garages, carports, and covered patios [Section 11-2-3(J)].

Understanding and Calculating Lot Coverage in Mesa

Within the City of Mesa, lot coverage is defined as the area of a parcel covered by impervious surfaces. This includes buildings, patios or decks with roofs, carports, tennis courts, and parking lots [Section 11-87-1].

When calculating coverage for a City of Mesa residential project, the following structures are included in the footprint:

All principal and accessory structures.
Garages and carports.
Covered patios and roofed porches.

The City of Mesa specifically excludes certain elements from the coverage calculation, such as:

Unroofed and unenclosed decks, patio slabs, and balconies less than 6 feet in height.
Eaves and roof overhangs that project 2.5 feet or less from a building wall.
Trellises or similar structures without solid roofs.
Swimming pools and hot tubs not enclosed in roofed structures.
One non-habitable accessory structure smaller than 120 square feet and under 7 feet in height [Section 11-2-3(J)].

Single Residence (RS) District Coverage Limits

The City of Mesa scales lot coverage allowances based on the density and minimum lot size of the RS sub-district. Larger lots intended for lower density have more restrictive coverage limits compared to smaller, higher-density urban lots.

Mesa Zoning District	Maximum Lot Coverage
RS-90 (90,000 sq. ft. min. lot)	40%
RS-43 (43,560 sq. ft. min. lot)	40%
RS-35 (35,000 sq. ft. min. lot)	50%
RS-15 (15,000 sq. ft. min. lot)	50%
RS-9 (9,000 sq. ft. min. lot)	60%
RS-7 (7,000 sq. ft. min. lot)	60%
RS-6 (6,000 sq. ft. min. lot)	60%

[Source: Section 11-5-3, Table 11-5-3.A.1]

Small Lot Single Residence (RSL) District Coverage Limits

The City of Mesa Residential Small Lot (RSL) districts are designed for higher-density detached housing. Because the lot sizes are smaller, the City of Mesa allows a significantly higher percentage of the lot to be covered by structures.

Mesa Zoning District	Maximum Lot Coverage
RSL-4.5 (4,500 sq. ft. avg. lot)	70%
RSL-4.0 (4,000 sq. ft. avg. lot)	75%
RSL-3.0 (3,250 sq. ft. avg. lot)	80%
RSL-2.5 (2,500 sq. ft. avg. lot)	80%

[Source: Section 11-5-3, Table 11-5-3.A.2]

Multiple Residence (RM) District Coverage Limits

For multi-family developments such as apartments, townhomes, and condominiums, the City of Mesa enforces a uniform maximum lot coverage across most RM sub-designations, including those with "Urban" (-U) character designators.

Mesa Zoning District	Maximum Lot Coverage
RM-2	70%
RM-3	70%
RM-4	70%
RM-3U	70%
RM-4U	70%
RM-5	70%

[Source: Section 11-5-5, Table 11-5-5]

Agricultural and Accessory Structure Limitations

In the City of Mesa Agricultural (AG) District, which often contains a single residence, the "Maximum Building Coverage" is strictly limited to 15% [Section 11-4-3, Table 11-4-3].

Additionally, the City of Mesa limits the size of detached accessory buildings (such as barns, sheds, or ramadas) based on the size of the primary residence. The combined floor area of all detached accessory structures may not exceed 100% of the primary building's floor area unless the City of Mesa grants a Special Use Permit [Section 11-30-17(A)(4)].

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