Mono County Municipal Code Ch. 15.20 House and Property Numbering

The purpose of this chapter is to establish a county-wide house and property numbering system that is consistent with Mono County General Plan Chapter 22 (Fire Safe Regulations) and the county 911 emergency response system. The specific objectives of this chapter are as follows:

A. To provide property owners and the county with a convenient, accurate and systematic means of identifying property.

B. To name new streets, and rename old streets with conflicting or duplicate names, in order to provide for the efficient provision of emergency services.

C. To provide a means for expedient emergency response by all necessary emergency services.

D. To establish a property location that will serve as an emergency 911 address.

E. To assist in the proper delivery of utility and other services.

F. To support the county's move to enhanced 911.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

This chapter shall apply to and govern each and every lot, parcel, or tract of land and improvement thereof, within the unincorporated areas of the county, in accordance with the implementation schedule set forth in Section 15.20.130. The structure numbers on all residential, multi-family and commercial buildings existing at the time this chapter is adopted will be checked to ensure conformance with the standards set forth in this chapter. If the existing structure number is found to be non-compliant, the director may assign a new number as set forth herein. All new and future structures will be assigned a primary structure number in compliance with this chapter.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

The assignment of numbers and the maintenance of the records pertaining thereto are the responsibility of the information technology department. The director of information technology ("director") shall be responsible for the administration of these standards and the maintenance of all maps and data relating to street names and addresses and will also determine if the assignment of names and numbers conforms to the standards set forth in this chapter. The director shall notify property owners of the assignment of property numbers and the effective date of display of the numbers. It shall be the responsibility of the property owner to erect or install occupancy or structure numbers compliant with Section 15.20.090 of this chapter and street naming signage compliant with Section 15.20.110 of this chapter. The director shall further assign numbers to all parcels created by any division of land. The director may assign such additional numbers as are necessary to identify separate occupancies or structures and may consult with the appropriate fire protection district and the Mono County Sheriff's Department to help resolve addressing issues.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

As used in this chapter:

A. "Address" means a combination of a number, a street name and, when necessary, a unit number that is assigned to a parcel, structure, or unit within a structure, and is unique to it, to indicate its location.

B. "Adjoining" means having a common boundary for at least twenty-five feet.

C. "Building" means any structure used or intended for sheltering or supporting any use or occupancy.

D. "Principal building" means a building that is large enough or used in such a way that, in the director's judgment, it requires a separate address. Mobile homes are principal buildings.

E. "Contrast" with regard to colors used for the numbers, means two dissimilar colors that, when viewed alongside each other, distinctly oppose each other, allowing them to be visible to the naked eye and that stand out against the prevailing background.

F. "Driveway" means a vehicle-way that provides access, primarily for the occupants, from a street into a lot or complex and that:

1. Has a ramp for its entrance from the street; and

2. Provides access to no more than two separate dwellings or addressed structures or to any number of dwellings or addressed structures within a single complex or development.

G. "High rise" means a multi-level building greater than three stories.

H. "Internal street" means a street within a multi-family development or complex or other development or complex that provides access to the development or complex from a driveway.

I. "Lot" means a parcel of real property.

J. "Property owner" means the person, firm, corporation or partnership that the latest county tax assessment rolls shows as the owner or long-term lessee.

K. "Primary driveway" means the primary point of access to a lot identified by property owner.

L. "Street" means a right-of-way or street easement, whether public or private, that provides vehicular access to abutting property.

M. "Structure" means a building, modular or the like, which is assembled or constructed on the ground, or attached to anything with a foundation on the ground. This includes mobile homes and manufactured housing regardless of their method of attachment.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

This section pertains to the standards which apply when naming streets. Regulations pertaining to the process and procedure for the adoption of street names are set forth in Chapter 13.35 or Subdivision Map Act and Section 17.16.250 of this code.

All streets that serve three or more properties under different ownership will be named regardless of whether the ownership is public or private.

A. Driveways shall not be named.

B. A street name assigned by the county shall not constitute or imply acceptance of the street into the county's road system.

C. There shall be no duplication of names by sound or spelling (e.g. Pine Road and Pine Lane, or Beach Street and Beech Street).

D. When a proposed street is in general alignment with an existing street, and the proposed street is to be a continuation of the existing street, the existing name and designation should be maintained.

E. Each street will have the same name throughout its entire length.

F. No street name shall be over sixteen characters in length. In counting characters, spaces between words shall be included, but street name suffixes (e.g. road, drive, lane, circle) shall not be included.

G. Address plans shall be submitted with the tentative map and before submittal of a final map; the subdivider shall submit a street naming and addressing plan to the information technology department. In addition, if any property owner proposes to locate or construct a new road (private or public), the property owner shall submit a street naming and numbering plan to the information technology department. Address plans must be approved prior to map recordation.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

The following standards shall apply when assigning numbers to buildings, dwellings, or other structures when only one principal building is on the property:

A. Official property numbers shall proceed from a logical point of origin. Each street will have a point of origin as a zero starting point for address numbers.

B. All dead end streets and culs-de-sac shall begin with ascending numbers at the open end that connects to another street.

C. Allowances shall be made for vacant lots in order that numbers may be properly assigned for future development.

D. Numbers will be assigned along both sides of a street. Odd-numbered addresses will be assigned on the north side of east-west streets and on the west side of north-south streets. Even-numbered addresses will be assigned on the south side and east side, respectively.

E. Numbers shall be established based on the front entrance from the street as designated by the county.

F. The number shall be displayed upon the front of the building and/or on the side facing the street throughout the year in summer and winter. The number shall be plainly visible from the street. Houses that are set back out of view from the street shall place a sign at the driveway entrance upon which shall be affixed the specified numbers.

G. For lots that are accessed by multiple driveways, a primary driveway shall be identified, which will be used for address assignment. Such access points are subject to review and approval of the director to ensure they are accessible to emergency service providers.

H. The assignment of a building number/address is required prior to the issuance of a building permit.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

The following standards apply to multi-family residential complexes or developments or any other complex or development that is serviced by a common driveway or driveways and parking area(s), without internal streets (for purposes of this section "complex"):

A. Each complex must have a county approved name designating it, which shall be made known at the time of permit application. This name shall be preserved, utilized, and prominently displayed at the complex. The address for the complex shall be prominently displayed as well.

B. For complexes that are accessed by multiple driveways, the county shall designate a primary access point associated with the driveway that most directly accesses the manager's unit or main office; this building will be used for address assignments and shall be known as the "primary driveway." Such access points are subject to review and approval of the county.

C. A multi-family dwelling structure such as an apartment building will be assigned one street address, and individual numbers for each unit, by the county.

D. If more than one building is present in a complex, each building must be assigned a building letter or number per the standards set forth in Section 15.20.050(G).

E. Each entrance serving a separate occupant, shall be assigned a unique unit number, however, it will maintain the address of the property upon which it is built and the letter of the building it is in. (Example: 24 Public Road, Building A, Unit 103).

F. Unit designators shall be as follows: Ground level floor numbers #101, #102, #103, second floor numbers #201, #202, #203. Additionally, all floor levels are to follow this scheme. Underground floor designator shall follow the same scheme with the exception of having "U" for a prefix, for example #U101, #U102, etc.

G. Unit numbers shall be at least four inches in height, made of a contrasting color to the background, and placed next to the door.

H. Mobile home parks shall be assigned one address based on the location of the primary driveway. Individual numbering of each mobile home space must be determined and provided to the county before an address will be issued to the park. (Example: 24 Public Road, Lot 1).

I. In the case of mall or a shopping center, the owner of any business that is located within such mall or shopping center shall display the legally assigned space or unit number at the main entrance to the business. Additionally, the owner of each business shall display the legally assigned number on the rear door to the building in numbers that are not less than four inches in height.

J. The assignment of an address is required prior to the issuance of a building permit. The director will approve each address, including building letters and unit numbers.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

The following standards apply to multi-family residential complexes or developments or any other complex or development that is serviced by a common driveway or driveways and parking area(s) but which has internal streets (for purposes of this section "complex").

The complex shall use the address assigned to the property during the construction phase of the project only. After the project has been built, the 'parent' address is retired and superseded by the individual unit address. All structures, dwellings, common-area facilities, alarms, and other infrastructure must comply with the following:

A. Whenever a network of named streets exists within a complex, the street names shall be utilized in the addressing of the structures they service. All street names must comply with Section 15.20.060.

B. The address shall be displayed upon the front of the building and/or on the side facing the street. The number shall be plainly visible from the street. All numbers shall meet the standards discussed in this chapter.

C. Each entrance serving a separate occupant within each building shall be assigned a unique address based on the location of the driveway or garage that services said unit. Numbers shall be displayed according to the standards set forth in Section 15.20.090.

D. The assignment of building numbers and addresses is required prior to the issuance of a building permit.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

Address numbers shall comply with the following specifications:

A. Address numbers shall be made of durable material.

B. Address numbers shall be depicted in Arabic numerals or shall be the English words for such numbers.

C. Address numbers shall be clearly visible from the street during both summer and winter months but no digit or letter shall be smaller than four inches in height.

D. Structures located more than fifty feet from the street and/or not clearly visible from the street shall comply with the above standard by maintaining a post at the intersection of the driveway and street. Said post shall be at least three feet in height of durable material with address numbers posted on it. Said numbers shall be at least four inches in height. In all cases, a larger number than the minimum size may be required where the minimum size does not provide adequate identification.

E. The color of the address numbers shall contrast with the immediate background so as to be easily readable.

F. It shall be unlawful to cover or conceal, or to permit the obstruction of the address numbers. All numerical identifications must be easily identifiable without obstruction of view.

G. It shall be unlawful to post numbers other than the primary address.

H. All old numbers shall be removed when a new address number has been assigned in accordance with this chapter.

I. The property owner shall maintain numbers in such a manner that they continue to comply with the foregoing specifications.

J. Structure numbers and unit designators, as viewed from the street, shall not be obstructed from view.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

A. Each building in a multi-building development or complex shall receive a unique letter, beginning with A. Alternatively, buildings may be given names, but the first letter of the name shall not be used in the name of any other building in that complex or development. (Ex. A, B, C, or Aspen, Birch, Cherry.)

B. Buildings shall be lettered in alphabetical order as you drive through the complex.

C. Building letters are to be at least one foot in height, made of contrasting color, and shall be conspicuously located and placed on the side of the building facing the driveway or street at least ten feet off the ground so as to clearly identify the building they relate to year-round.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

Installation and maintenance of street name signs will be done as follows:

A. In subdivisions, the property owners' association (or other similar entity) which represents the property owners in the subdivision, or the property owners in said subdivision (if there is no property owners' association or similar entity) shall be responsible for installing and maintaining street name signs with the approved name of the street and the intersecting street in accordance with the specifications in this chapter. The foregoing shall not apply where a street is county-maintained, or intersects with a county-maintained street at the intersection.

B. In all other cases, the property owners adjoining the street shall be responsible for installing signs with the approved name of the street and the intersecting street in accordance with the specifications set forth in this chapter. The county will only be responsible for installing street name signs for county-maintained streets.

C. No occupancy permits for any building or buildings to be erected shall be issued until such time as the street name signs are installed.

D. Street signs shall meet all state and county standards.

E. Signage must conform to all applicable state and county standards, including standards set forth in the manual uniform traffic control devices:

1. Posts and mountings shall be permanent and durable. Post materials shall consist of a standard four-by-four wood post or alternate materials or construction that meet nationally accepted breakaway standards.

2. Mounting height:

a. Rural areas: A minimum of five feet, measured vertically from the bottom of the sign to the elevation of the near edge of the pavement.

b. Business, commercial or residential areas where parking or pedestrian movements are likely to occur: Seven feet, measured vertically from the bottom of the sign to the elevation of the near edge of the traveled way.

3. Orientation:

a. Business or commercial areas: Street name signs shall be placed on diagonally opposite corners.

b. Residential areas: At least one street name sign shall be mounted at each intersection. They shall be mounted with their faces parallel to the streets they name.

c. At intersection crossroads where the same road has two different street names for each direction of travel: both street names may be displayed on the same sign along with directional arrows.

4. Sign lettering: Lettering on post-mounted street name signs shall be composed of initial uppercase letters at least six inches in height and lower-case letters at least four and one-half inches in height. On multi-lane streets with speed limits greater than forty mph, the lettering on post-mounted street name signs shall be composed of initial upper-case letters at least eight inches in height and lower-case letters at least six inches in height.

Option: For local roads with speed limits of twenty-five mph or less, the lettering on post-mounted street name signs may be composed of letters at least four inches in height.

5. Retroreflectivity and illumination: Street name signs and object markers shall be retroreflective or illuminated to show the same shape and similar color by both day and night.

6. Lateral offset: Street name signs shall be installed in urban areas at all street intersections regardless of other route signs that might be present and should be installed in rural areas to identify important roads that are not otherwise signed. All supports should be located as far as practical from the edge of the shoulder.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

Numbers shall be affixed within sixty days after assignment and in accordance with this chapter, or as otherwise authorized by the director.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

A. New Streets and Addresses. All streets or lots created following adoption of this chapter shall comply with the standards set forth herein. In situations where such assignment would result in incongruity amongst the existing numbering system, a temporary address may be assigned and later replaced with a permanent, compliant address.

B. Existing Streets and Addresses. Unless otherwise authorized by the director, streets and structures that are not in compliance with the standards set forth in this chapter will be changed per resolution, adopted with or pursuant to this chapter.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)

In the event that any number assigned to any structure under this chapter or under a resolution adopted pursuant to this chapter, is not affixed thereto in accordance with the requirements of this chapter, the property owner may be subject to administrative citation in accordance with Chapter 1.12.

(Ord. No. 26-001, § 1(Att. A), 2-10-2026)