Address Terms And Concepts#
Address Block – An address block is approximately 1/10th of a mile in the address grid. Blocks will generally start and end at major intersections, but may cross minor intersections along road segments shorter than 1/10th of a mile. Road segments longer than 1/10th of a mile will include multiple blocks. A block may also suggest a group of lots defined as a Block on a land survey plat utilizing the Lot and Block naming convention to describe land records.
Address Change – An address change may be issued due to an error made at the time of initial addressing, a change of use to a property, or any reasonable request by the owner of the property. This process is detailed in Section V.
Address Grid – The address grid is based upon Public Land Survey System (PLSS) sections and divides the City into blocks for the purpose of assigning addresses. There are ten blocks per mile and 100 blocks per square mile section.
The base lines for Fort Collins are Mountain Ave, which establishes the east-west base and College Ave, which establishes the north-south base. The first block north, south, east or west of this intersection is the 100 block.
Address Increment – Addresses for single-family lots along a block are generally separated by six (i.e. x02, x08, x14, x20, etc.), which leaves two numbers between each lot for infill addresses on each side of an odd or even-numbered block. Larger lots may include more separation between address numbers. A set of numbers (x00, x01, x98, and x99 at a minimum) are generally reserved at the start and end of each block for non-mailing utility addresses.
Address Range – A term used to identify a series of blocks or addresses on one street. The standard for odd and even numbers places even numbers on the north side of east/west streets and the east side of north/south streets.
Alpha Addresses – Alpha characters are not permitted in addresses, unless used for secondary addresses identifying duplex, triplex, and fourplex units (i.e. A, B, C, D) or accessory dwelling units on a property. These letters increase in the same direction as street addresses.
Alpha characters are not used for building designations. Developments with multiple buildings may include individual street addresses when fronting public ROW or a single primary address combined with building numbers if the site is contained and there is limited access to the site from public ROW.
Business Park – Each building within a business park generally retains a unique street address.
Campus Address – In locations where there is a campus or group of buildings with one major access point, a single address is assigned to the point of access and building numbers are applied to each building.
Corner lots – Corner lots at the intersection of two or more streets may receive an address assigned to each street to remain active throughout construction. A corner lot’s final address shall be determined upon completion of a building’s certificate of occupancy. The address identifying the building’s primary access shall remain active and the additional addresses originally assigned to the lot shall become inactive.
Grid Block – A square block of 528 feet by 528 feet, which is 1/100th of a square mile area, as defined by the address grid.
Staggered Addresses – Staggered addressing is the method of forcing the address from one side of the street to match or nearly match with each other. It often happens in a new subdivision with curvilinear streets that have more lots on one side of the street than the other. When this occurs, addresses on the short side of the block are eliminated, or staggered, in an attempt to keep facing addresses from across the street more closely aligned with each other. It is desirable for the police and emergency services to know that the address across the street is at or near the same physical address, and it is desirable to have a strong association with beginning and ending address sequences at intersections or address break points.
Street Naming Standards – Per an intergovernmental agreement between the City and County, standards have been established for the naming of streets, acceptable prefixes, and suffixes. These standards are found on Larimer County's website. The process for reserving street names in the City of Fort Collins are detailed in Section II.
Suite – A secondary address that identifies tenant space for commercial offices or retail.
Unit – A secondary address that identifies separate residential space within a building or accessory dwelling units on one property. Fractional numbers are not permitted.
Unit Level Addressing – Where buildings are divided to contain more than one occupant (often termed the tenant finish), the City of Fort Collins does not assign additional street addresses. Instead, secondary addresses for commercial suites and residential units are assigned as accessories to the primary address. This process is detailed in Section IV.
Street Name Approval#
Street name approval is required for all public right-of-way and private drives, in order to maintain standards for emergency response within the Larimer Emergency Telephone Authority service area. All proposed street names are verified against the Larimer County Street Inventory System ( Street Inventory). Duplicate street names and/or phonetic similarities are not allowed.
Proposed street names are evaluated during the Development Review process. Acceptable names are added to the Larimer County Street Inventory System, while unacceptable names are returned to the project’s applicant for replacements. Any policies adopted by Larimer County not listed below supersede this document.
Standardization of Road Naming Criteria (per Larimer County)
- Use only accepted suffixes.
- Homonyms for road names are not acceptable.
- Road names should be unique and not repeated in the County from this point forward, with the exception of continuation of existing streets. A different suffix (e.g. DR, ST) does NOT make a name unique.
- Each Municipality and the County may develop a list of acceptable or recommended names for use in its jurisdiction. If there are duplications on such lists, and another Municipality or the County utilized the name, the name will be removed from the acceptable or recommended lists in the other jurisdictions.
- Within the Growth Management Area around each Municipality, roads will be named using city/town names, not County road numbers. Outside of the GMA Boundary, County road numbers will be used. Street names, rather than County road numbers, will be used for internal roads in County subdivisions and 35-acre developments.
- In the unincorporated area any road that serves as an access to multiple properties must be named. Multiple properties accessing of a single point from a County road may not use the single access point as a common address.
- Continuous roads should have continuous names (with the exception of circle roads). Names should not change except at the Growth Management Area boundary; however, names are not required to change at the Growth Management Area boundary.
- Recommend that road names must be simple to pronounce, in the opinion of the review jurisdiction.
- Cardinal directions cannot be used in the name. Directions are used only to designate the portion of an existing road. (not acceptable - North Road, East Fort Road, Northstar Drive.)
- No curse words or derogatory terms shall be used for road names.
- These are meant to be minimum standards for each Municipality and the County. The main objective is to provide clear street names for citizens and for emergency dispatch and to minimize the possibility of emergency personnel being unable to find a location. Nothing in this Agreement is intended to limit any Municipality or the County from developing more extensive street naming guidelines.
- Numerical addressing will not change from the current process.
- All names shall be of the commonly acceptable spelling, according to a standard dictionary.
- Street names cannot contain any punctuation or special characters. Only alphabetical symbols A through Z, and numbers 0 through 9 and blank spaces may be used in street names.
- Anytime that a street makes a directional change of approximately ninety degrees, the street name shall change. A directional change of approximately ninety degrees shall mean a horizontal curve where a reduction in the design speed is required (i.e. a sharp turn vs. a sweeping curve).
- Existing street names shall continue across intersections and roundabouts.
Additional Standards for the City of Fort Collins
- Directional prefixes and suffixes are not permitted, unless the street crosses the base lines of College Ave or Mountain Ave.
- Numerical street names (1st, Second, etc.) and lettered street names not forming words (A, BB, etc.) are not permitted.
- Hyphenated street names or apostrophes are not permitted.
Approved Suffixes (per Larimer County)
The following table of suffixes are the only ones that can be used for new street names.
A roadway or thoroughfare that is continuous and not limited to a single subdivision.
Street with a landscaped median dividing the roadway.
Discouraged but allowed, at the discretion of the local jurisdiction.
Permanently dead-end street or terminating in a cul-de-sac, not longer than 660 feet in length.
A curvilinear street.
Minor street within a subdivision.
A thoroughfare designated as a collector or arterial, with a median reflecting the parkway character implied in the name.
Permanently dead-end street, terminating in a cul-de-sac, or short through street, not longer than 660 feet in length.
A designated thoroughfare.
The common or default suffix.
A curvilinear street.
Upon record of a new subdivision plat, all buildable lots are assigned an address to the street fronting a building’s primary access. Address assignment occurs in coordination with emergency services, in order to support best response methods. The location and access of each building along an address block shall establish the appropriate address number. Numbers outside of the address block range are not permitted. Existing addresses assigned to vacant lots or former buildings are not always preserved for new construction.
Addresses are even numbered on the north and east sides of a street and odd numbered on the south and west sides of a street. Streets shall have only one address range: extending east/west or north/south. Streets that change direction shall maintain the existing address range.
Address numbers for single-family lots are generally separated by six, which leaves two available numbers in the appropriate odd or even range between each lot for infill addresses. Larger lots may include more separation between address numbers. A set of numbers are generally reserved at the start and end of each block for non-mailing utility addresses.
Multi-use or Mix-use Buildings – Buildings with suites and/or apartment units residing within the same building shall have one address for the building with unit-level addressing assigned to the individual units. This is to avoid confusion when emergency services respond to a building's fire alarm signal.
Corner Lots – Corner lots may receive two or more addresses if the building orientation is not defined when the subdivision plat is recorded. One address is assigned to each street to remain active throughout construction. A corner lot’s final address shall be determined upon completion of a building’s certificate of occupancy. The address identifying the building’s primary access shall remain active and the additional addresses originally assigned to the lot shall become inactive.
Non-mailing Addresses – Non-mailing addresses may be assigned to properly identify locations for utility services, monument signs, or other uses requiring permits. Depending upon the location, these addresses use available numbers at the start or end of each block or infill addresses between existing buildings.
Secondary Addresses for Units or Suites – Secondary addresses for units or suites are established when a building permit is issued for a tenant finish to split an existing space. Guidelines for secondary addresses are detailed in Section IV.
Secondary Addresses For Units/Suites#
Where buildings are divided to contain more than one occupant (often termed the tenant finish), the City of Fort Collins does not assign additional street addresses. Instead, secondary addresses for commercial suites and residential units are assigned as accessories to the primary address. This process provides for a consistent method of assigning unit/suite numbers by floor or level within the structure.
Procedure – Whenever an additional tenant space is created, the City of Fort Collins requires a Unit Level Addressing form to be completed and filed with the City. This document can be found at:
After completing the contact information on the form and including a floorplan or sketch of the layout, it is emailed to the GIS Department firstname.lastname@example.org. The City of Fort Collins GIS Department will assign the appropriate units/suites and forward the information to USPS, Poudre Fire Authority, Fort Collins Utilities, and Building Services.
Floor plans or a sketch of the tenant spaces of the entire structure are required, so that new units/suites are consistent with the range and format of any addresses already in place.
Timeline for Address Assignment – Floor plans must be submitted with all new construction during the Development Review process, so that all addresses (primary and secondary) may be assigned once the project is recorded. For any tenant finishes occurring in existing structures, secondary address assignment should be requested prior to or during construction, but before any utilities are set, in order to ensure utility meter banks match the official addressing for the structure.
Guidelines for Secondary Addresses
- Units/suites shall match the floor on which they reside. (i.e. 100s – 1st floor, 200s – 2nd floor, 300s – 3rd floor, etc.)
- For buildings with multiple floors and similar floor plans, addresses shall attempt to preserve the same last two digits of the addresses on floors immediately above and below. (102, 202, 302, etc.)
- If units are located below ground level, they will be assigned a number less than 100. (i.e. Units 20, 30, 40, etc.). PFA prefers 020, 030, 040 to be displayed on signage, but USPS prefers no leading 0 in mailing addresses, in order to avoid any issues with mail delivery.
- It is recommended that commercial suites increase by tens (110, 120, 130, etc). This leaves room for in-fill addressing between existing suites.
- Alpha characters are not permitted in secondary addresses, unless used for duplexes, triplexes, and fourplexes (i.e. A, B, C). These letters increase in the same direction as street addresses.
- Alpha characters are not used for building designations. Developments with multiple buildings may include individual street addresses when fronting public ROW or a single primary address combined with building numbers if the site is contained and there is limited access to the site from public ROW.
- The designation of UNIT shall identify residential spaces and SUITE shall identify commercial spaces.
- Secondary addresses are assigned starting at the main point-of-entry and increasing toward the end of the hallway, similar to hotel numbering.
Distribution – Approved ULA forms are distributed to the following:
Poudre Fire Authority
Fort Collins Utilities
Address Change Procedure#
An address change may occur when access to a property and/or building has changed, in order to more accurately correspond to the primary entrance.
Address change requests must be in writing and delivered to the City of Fort Collins GIS Department (email@example.com). Requests may be made only under the direction of the property owner. This ensures that the property owner is fully aware that a change has been requested for one or more tenant spaces and how a change may impact records for the location. The City of Fort Collins GIS Department will notify the owner confirming receipt of the request and that the requested change is being researched.
If it is determined that an address change is warranted, an Address Change Memorandum is delivered to the owner and recipients listed below. A change may take several weeks or more for external customers to fully adopt. Not every request for a change is granted, as the primary function of proper addressing is to aid emergency services. If it is determined that an address change is not warranted, a letter of explanation is sent to the owner.
Recipients of Address Changes
Fort Collins Building Services
Fort Collins City Clerk
Fort Collins Police Services Fort Collins Utilities
Larimer County Assessor
Larimer County Elections Department
Poudre Fire Authority
US Postal Service