Chapter 27.70 — ACCESSORY BUILDINGS AND STRUCTURES IN REQUIRED YARDS

(a) Location of Detached Accessory Buildings. A detached accessory building located within the rear one-third of a parcel is exempt from the requirements for interior side and rear yards, provided such structure is separated from the principal building by an area not less than four (4) feet in width that is open to the sky.

(b) Maximum coverage of required rear yards. Accessory buildings shall not occupy more than 50% of a required rear yard.

(c) Maximum height of accessory structures in required yards. Accessory structures located in required yards pursuant to subsection (a) shall not exceed the following height limits:

R1 Districts Nine (9) feet to the plate line and sixteen (16) feet to the roof peak. All other districts Fifteen (15) feet to the plate line.

(d) Habitable floor limitation. In R1 Districts, accessory structures located in required yards pursuant to subsection (a) shall be limited to one habitable floor on the ground level. Habitable floor for the purposes of this subsection shall mean that served by permanent access and containing windows and/or plumbing fixtures, but shall exclude basements.

(Ord. No. 1992-16 § 17.) Cross References Section 27.70.020(d)(1) Section 27.70.020(e)(1)

(a) R1 Districts. In R1 Districts, Section 27.18.100 shall govern structures or building projections in required yards.

(b) All other districts. For all other districts, the following structures, building projections or features shall be permitted in all yards:

(1) Overhanging eaves and gutters projecting a maximum of three (3) feet or fifty percent (50%) of the required yard width, whichever is less;

• (2) Awnings, canopies and covered patios;

(3) Greenhouse or oriel bay windows projecting three (3) feet or less into a required yard, provided that the outside face of the projection shall be at least three (3) feet from the property line;

(4) Chimneys projecting two (2) feet or less into a required yard provided that the outside face of the chimney shall be at least three (3) feet from the property line;

(5) Arbors and trellises having a maximum height of eight (8) feet;

(6) Flag poles, garden ornaments and play equipment;

(7) Fences, subject to provisions of Chapter 27.84 of this title;

(8) Basements which are completely below grade;

(9) Steps which are necessary to provide access to the first living level of a permitted building or to a parcel from a street or alley;

(10) Open swimming pools and spas, subject to setbacks from property lines established in Section 23.44.030 of this title.

(c) Front yard projections. For districts other than R1, the following structures or building projections shall be permitted in front yards:

(1) Balconies or decks projecting six (6) feet or less into the required yard;

(2) Porte cochere or similar pedestrian entry feature in multi-family or commercial developments which are less than six hundred (600) square feet in total area and have a width less than twenty (20) percent of the property street frontage.

(d) Rear yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in rear yards:

(1) Accessory structures subject to provisions of Section 27.70.010 of this title;

(2) Open parking spaces;

(3) Balconies or decks projecting six (feet) or less into the required yard;

(e) Interior side yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in interior side yards:

(1) Accessory structures subject to provisions of Section 27.70.010 of this title;

(f) Street side yard projections. For districts other than R1, the following structures, building projections or features shall be permitted in street side yards:

(1) Balconies or decks projecting not more than three (3) feet, provided that the distance between the projection and the street property line shall be at least 7.5 feet.

(2) Porte cochere or similar pedestrian entry feature in multi-family or commercial developments which are less than six hundred (600) square feet in total area and have a width less than twenty (20) percent of the property street frontage.

(f) In all districts, covered pools are not allowed in required yards.

Chapter 27.71 LANDSCAPE FOR PLANNING APPLICATIONS

The purpose of this chapter is to enhance the quality of life in San Mateo by the provision for appropriate design of landscaping and through the preservation of existing trees. Landscaping shall be a major component of all site design in order to create a city that has a strong landscaped character. The intent is that individual neighborhood character be developed and maintained, architecture be softened by plant materials where appropriate, conflicting uses be buffered, parking areas be screened, comfortable outdoor living and walking spaces be created, air pollution be mitigated and future developments be made water efficient.

(a) This chapter shall apply as a minimum for all projects requiring approval of a planning application pursuant to Section 27.08.010, except for single-family dwelling design review applications. Landscaping not subject to this chapter shall be governed by the provisions of Chapter 13.40. The Zoning Administrator may determine that minor additions or changes to existing property are not reasonably related to the purpose of this chapter and may be exempt from the requirements of this chapter.

(a) Required Landscaping. All required front and street side yards shall be landscaped, except for necessary driveways and walkways. In all other areas landscaping shall be required except for necessary circulation areas, paved outdoor living areas or water features.

(b) Buffering and Screening. Plantings shall be provided to buffer residential uses from commercial or industrial uses. Plantings shall also be provided to screen service and storage areas, parking lots or unsightly areas. Plantings shall be used where appropriate to control noise, wind, climate and ensure privacy.

(c) Outdoor Living Areas. Landscaping shall be arranged so as to provide usable outdoor living areas where appropriate. Plant materials and architectural features should be used to control noise, sun and wind and provide adequate privacy.

(d) Composition of Required Landscaping. All required landscaping shall include the planting and maintenance of some combination of trees, groundcover, shrubs, vines, annuals and lawns.

In addition, the combination or design may include natural or structural features, including, but not limited to, fountains, reflecting pools, artwork, screens, walls, and fences.

(e) Security. Landscaping shall be installed and maintained to provide aesthetic quality while promoting building security.

(f) Minimum Requirements. The provisions contained in this chapter are intended to be a minimum standard. Compatibility with other projects and compliance with required findings and adopted goals and policies of the City shall be evaluated through the planning application process.

The following definitions shall apply to this chapter:

(a) "Existing Trees" means all existing trees over six inches in trunk diameter (measured at 54 inches from natural grade) on the subject property and any Protected Trees on the subject property or any property within 30 feet of the proposed Construction Activity, as outlined in Chapter 13.40.

(b) "Groundcover" means low growing live perennial vegetation, other than turf, of a species which is sold as a groundcover or shrub by licensed nurserymen.

(c) A "heritage tree" is as defined in Chapter 13.40.

(d) "Landscape" or "landscaped area" means an area that consists of living plantings.

(e) "Landscape unit (LU)" means the unit of measurement for trees which indicates the worth of each relative to one another and towards satisfying City requirements.

(f) "Natural landscaping" means an area consisting of uncultivated native plant growth and other features of natural terrain such as rock outcroppings, streams or other areas covered by water.

• (g) "Plantings" means annuals, groundcover, turf grass, shrubs or trees.

(h) "Protected Tree" means a Heritage Tree or Street Tree as defined in Chapter 13.40 or a

tree designated as protected as part of an approved Planning Application that is subject to this Chapter.

(i) "Project Arborist" means an ISA Certified Arborist designated to evaluate the potential impacts of Construction Activity on Protected Trees, write specifications for tree preservation, oversee Construction Activity within the Dripline of Protected Trees and other necessary activities as determined by the City Arborist.

(j) "Shrubs" means live perennial vegetation, greater than an average height of two (2) feet and maintained below twelve (12) feet in height. Vines shall be considered shrubs.

(k) "Street Tree" means any woody perennial plant having a single main axis or stem capable of achieving ten (10) feet or more in height, growing along or within public right of way or planted within public right of way or a designated planting easement.

(l) "Trees" means a live self-supporting woody plant having at least one well defined stem or trunk and normally attaining a mature height and spread of at least twelve (12) feet, and having a trunk that may, at maturity, be kept clear of leaves and branches at least six (6) feet above grade.

(m) "Turfgrass" means live vegetation of a species normally grown as turf by a nursery and which is maintained at a height of three inches or less.

All landscape areas shall be maintained free of weeds, litter and debris. All plantings shall be maintained in a healthy growing condition and whenever necessary, replaced with equivalent plant materials to ensure continued conformance with approved plans.

A plant establishment period of three growing season months (March through October) shall be required for all landscape areas. At the completion of this period all plant materials shall be in a healthy condition and the landscaped area shall be maintained free of weeds, litter and debris.

(a) For projects with less than 10,000 square feet of landscaped area, proof of a contract with a licensed landscape contractor to maintain the landscape for the plant establishment period shall

be submitted.

(b) For projects with greater than 10,000 square feet of landscape area and for all residential condominiums, financial securities shall be held by the City as required in Section 27.71.090 to ensure compliance with the plant establishment period.

(a) All landscape plans must be at a reasonable scale to indicate all types of improvements. All plans must contain sufficient information to ensure conformance with the requirements of this chapter and must include, but are not limited to, the following information:

(1) North arrow and scale;

(2) The name of the applicant/owner;

(3) The name, address, and phone number of the person or firm responsible for the preparation of the plans and other required information;

(4) The dates the plans are submitted and revised;

(5) All existing and proposed buildings and other structures, paved areas, planted areas, power poles, fire hydrants, light standards, signs, fences, and other permanent features to be added and/or retained on the site;

(6) All existing plant material to remain and to be removed, a tree evaluation schedule identifying Major Vegetation (as defined in Chapter 23.40) and all Protected Trees including trunk diameter, species, the condition of trees to be removed as determined by an arborist and the existing and proposed replacement Landscape Unit (LU) values;

(7) All existing and proposed streets, sidewalks, curbs and gutters, railroad tracks, drainage ditches, and other public or semi-public improvements within and immediately adjacent to the site;

(8) Contour lines, if the slopes are in excess of 10%;

(9) Existing and proposed topographic elevations at sufficient locations, to clearly show the drainage pattern unless this information is provided on a grading plan or other documents in the planning application;

(10) All property lines and easements;

(11) Square footage of all planted area;

(12) Species, sizes and location of all proposed plant material including the accurate driplines of all Protected Trees;

(13) Soil tests as required by the discretion of the Zoning Administrator; and

(14) A tree protection plan consistent with Chapter 13.40 and the Administrative Guidelines.

(b) All projects with over 1,000 square feet of new or modified planting areas as required to meet the provisions of this chapter shall have all landscape plans and accompanying documents prepared or reviewed and found acceptable by a licensed landscape architect registered with the State of California.

(a) All of the required submittals for a planning application;

• (b) Type and depth of mulch indicated on the plan;

(c) An irrigation plan accurately drawn to scale that indicates all components of the irrigation system including sprinklers and other outlets, valves, the backflow prevention device(s), controller(s), and piping;

(d) All tree information required in Section 27.71.150 and Chapter 13.40;

(e) For projects with less than 10,000 square feet of landscaped area, proof of a contract with a licensed landscape contractor to maintain the landscape area for the plant establishment period;

(f) For projects with greater than 10,000 square feet of landscape area, financial securities as required in Section 27.71.090; and

(g) Soil tests as required in Section 27.71.110.

(a) Prior to use, final inspection, or the issuance of certificate of occupancy, all landscaping shall be installed in conformance with the approved plans.

(b) Phased Projects. Incremental landscape installation may be permitted by the Zoning Administrator when building construction is phased.

(c) Financial Security. Financial security shall be required for all projects with over 10,000 square feet of landscape area and for all residential condominiums. On smaller projects where adverse weather, drought conditions or project phasing prohibit the installation of landscaping, the Zoning Administrator may allow financial security to be submitted to the City in order to allow use or issuance of a certificate of occupancy. The security shall be in a form which is legally sufficient to ensure the preservation of trees and the installation of all approved landscape improvements. Financial security shall be returned to the applicant upon completion of the plant establishment period. The City shall be the beneficiary and the sole determinant of compliance and completion. A detailed cost estimate of all landscape improvements plus the value of any existing trees to remain, as determined in Section 27.71.150, shall be used to determine the amount of security.

(Ord. No. 2015-3 § 2; Ord. No. 1989-34 § 1.) Cross References Section 27.71.060(b) Section 27.71.080(f)

27.71.100 LANDSCAPE COMPATIBILITY AND SOIL TESTING.

The location and nature of all landscaping shall be compatible with the soil, amendments, existing plantings to remain and character of the landscaping in the vicinity. For projects with over 10,000 square feet of landscape area or in areas of questionable soils such as the foothills or areas of bay fill, soils testing shall be required. Testing shall be performed by a professional testing laboratory. Soil shall be amended according to test report recommendations.

(a) Allowed Bare Ground. Areas of bare ground or ground covered only by bark or rocks shall be allowed on-site only where required as part of an approved facility, such as a baseball diamond, vegetable garden, flowerbed, or similar use.

(b) Allowed Natural Landscaping. Natural landscaping shall be allowed only in areas where it is compatible with the surrounding environment.

(c) Minimum Tree Size. All required trees shall be a minimum size of 15-gallon container at time of installation, except for heritage tree replacements, which shall be replaced according to Chapter 13.40 and the Administrative Guidelines.

(d) Plant Coverage.

(1) Trees shall be planted at a minimum ratio of one per 400 square feet of required landscaped area. The ratio may include existing trees and required parking area trees. Public parks, golf courses, cemeteries, school recreation areas and public facilities need not comply with this ratio.

(2) Groundcover and shrub massing areas shall be planted in a manner or at the spacings recommended by the American Association of Nurserymen, to uniformly cover the proposed groundcover areas within two years and the shrub areas within five years or a period optimum for the species.

(e) Security Planting. The use of plant materials that promote building security is encouraged. A list of such materials may be obtained from the Planning Division. Perimeter landscaped areas should incorporate thorny plant materials to discourage persons from cutting through parking areas, trampling vegetation near ground floor windows, or climbing perimeter fences and walls.

(Ord. No. 2021-26 § 8; Ord. No. 2015-3 § 2; Ord. No. 2009-7 § 41; Ord. No. 2008-8 § 16; Ord. No. 1989-34 § 1.)

Cross References

Section 27.71.080(g)

(a) Tree Planting.

(1) 24-inch box size or larger street trees shall be planted along public streets in accordance with the City Street Tree Master Plan. The City Arborist shall have the authority to recommend planting of fifteen (15) gallon street trees when:

(A) Upon written request by the applicant; and

(B) The fifteen (15) gallon size trees are the only ones available in stock, or

(C) The quality of the fifteen (15) gallon size trees are superior to that available in 24inch box size.

(2) Trees shall be planted at a spacing not to exceed thirty (30) feet except to allow for utilities, street furnishings, driveways, or other features necessary to ensure public safety, as approved by the City Arborist.

(b) Access Easement. Where a planning application requires a parcel or tentative map, an access easement shall be required if the street trees are to be located on private property and no such easement exists. However, it is recommended that even when a parcel or tentative map is not required or included, an easement be provided to the City for site access purposes in the event of an emergency or a hazardous situation.

The following requirements shall apply to open parking areas containing five or more parking spaces.

(a) Setbacks. Whenever a parking area is located adjacent to any residential use or zone and along all street frontages, a landscape strip shall be provided that is equal in width to five percent of the parking lot depth or six feet, whichever is greater.

(b) Percentage of Parking Areas to be Landscaped. At least 10% of the open parking area shall be landscaped. The following shall be considered in computing the landscape area:

(1) Parking area includes all paved surfaces devoted to on-site circulation and parking;

(2) Only those landscaped areas within six feet of a parking stall or aisle shall apply towards meeting the 10% requirement;

(3) Areas to be considered shall include planting areas and required curbing.

(c) Screening. All open parking areas shall be effectively screened on each side adjoining or fronting on any property in a residential zone and along all street frontages. Screening of adjoining property shall be a minimum of four feet to a maximum of six feet in height. Screening along street frontages shall be at least two and one-half feet in height for at least 80% of its length. Screening shall be accomplished by a wall, fence, earth berm, densely planted shrub mass or any combination of the above. Where walls or fences are provided, they shall be located adjacent to the edge of the parking lots. Screening shall conform with the sight distance requirements contained in Chapter 27.84 of the San Mateo Municipal Code.

(d) Parking Lot Islands.

(1) All islands and small areas unused for parking or circulation shall be landscaped. The Zoning Administrator may determine that certain areas for reasons of size, aesthetics or circulation should not be landscaped and may approve paving in those areas.

(2) Interior landscape islands, having a minimum dimension of five feet including curb, shall be provided after every 10 parking spaces in a row to provide for tree planting.

(e) Required Trees. For each three parking spaces at least one tree shall be planted within the parking lot landscaped area in addition to any required street trees. Existing trees may be included in the required total.

(f) Protection of Planting Areas. All planting areas shall be protected from common vehicular traffic. For parking lots containing five stalls or more, this requirement shall be met by a six-inchhigh vertical concrete curb. For parking lots containing less than five stalls, this requirement may be met by a concrete wheel stop in front of each diagonal or perpendicular stall plus a minimum six-inch-high concrete curb in other areas or approved equal. No trees or shrubs shall be planted and sprinkler heads shall be kept below curb height within two feet six inches of any curb or wheel stops which front upon parking stalls or backup areas.

The unpaved right-of-way area located between the public street and private property shall be landscaped in a manner compatible with the required landscaping on site. Such landscaping shall be permanently maintained by the property owner in conformance with the approved plans and so as not to create a safety hazard. Strips of public right-of-way located between the curb and sidewalks may not be paved but must likewise be landscaped. Long narrow strips of turfgrass such as traffic medians and areas between curbs and sidewalks are prohibited.

(a) Evaluation of Existing Trees. Trees over six (6) inches in trunk diameter, measured at 54 inches from natural grade and Protected Trees as defined in Chapter 13.40 shall be evaluated on the basis of species, size, condition, location and classification as a Protected Tree.

(b) Required Submittals. To evaluate the existing trees the landscape plan and a tree evaluation schedule shall be submitted with the planning application showing:

(1) The location of all existing trees six (6) inches or greater in trunk diameter (measured at 54 inches from natural grade), noting which are to be removed and which are located within the allowable building area;

(2) Trunk diameter in inches measured 54 inches above natural grade;

(3) Species name and species value as determined by utilizing the most recent edition of the Guide for Plant Appraisal, published by the Council of Tree and Landscape Appraisers;

(4) Condition and location value of trees as determined by an ISA Certified Arborist;

(5) The total LU value of trees to be removed; and

(6) The total LU value of replacement trees.

(c) Landscape Unit Value (LU).

(1) The tree species, condition, and location values of the trees shall be based on an evaluation by an experienced landscape appraiser recognized by the American Society of Consulting Arborists utilizing the most recent Guide for Plant Appraisal, published by the Council of Tree and Landscape Appraisers; and approved by the Zoning Administrator.

(2) Trees not within the allowable building area shall receive a location factor of 1.0 (100%). Trees located within the allowable building area shall receive a location factor of .70 (70%).

(3) Trees designated as heritage trees shall receive a bonus percentage value of 1.25 (125%). Trees located within the allowable building area shall receive a location factor of .70 (70%).

(4) Trees designated as heritage trees shall receive a bonus percentage value of 1.25 (125%). The species, condition and location value assume an average tree value to be .70 (.7 x .7 x .7 = .343). All existing trees to be removed shall be given a LU value based upon the following calculation:

species value% x condition value% x location value% Trunk diameter inches x bldg. ___________________________________________ x ________________________ = LU .35 setback% x heritage tree%

(d) Tree Replacement. Existing trees to be removed shall be replaced with new trees to equal the total removed LU value. The following rates shall be given to replacement trees to obtain the replacement LU value:

The LU value for replacement Street Trees shall be calculated separately from other replacement trees.

(e) Preservation of Heritage Trees. The site design shall make every reasonable effort to preserve Heritage Trees, consistent with Chapter 13.40. Conditions shall also be imposed to protect Heritage Trees during construction. Heritage Trees shall be removed only when the City Arborist determines that their preservation would result in a threat to health, safety, and welfare due to a hazardous tree condition, impacts on soil erosion and stability, or an unreasonable effect upon the economic enjoyment of the property, consistent with Chapter 13.40.

(f) Protection of Existing Trees. The site design shall make reasonable effort to protect existing trees. The design shall be evaluated as to how it protects existing trees or the reasons for removal of existing trees. Tree protection measures shall be provided for trees to remain on-site, which shall be consistent with Chapter 13.40 and imposed as a condition of approval s.

(g) Alternates to On-Site Replacement. If the required LU value for replacement of existing trees to be removed is not made up with replacement trees on-site, the City shall require that trees be planted in another location on-site or off-site or a contribution of funds be made to the City to be used for plantings on public land or a combination of the above options. If a contribution of funds is required, it shall be the fee as established by resolution of the City Council in the annual Comprehensive Fee Schedule.

(Ord. No. 2021-26 § 11; Ord. No. 2015-3 § 2; Ord. No. 2009-7 § 43; Ord. No. 1989-34 § 1.)

Cross References Section 27.71.080(d) Section 27.71.090(c)