• Going through the Development Review Process: Staff time spent reviewing development project proposals is split between taxpayers and applicants. https://www.fcgov.com/developmentreview/fees 

• Fees for electric service: These could include electric capacity fees, building site charges and any system modification charges necessary to serve the ADU project.  https://www.fcgov.com/utilities/business/builders-and-developers 

• Transportation infrastructure improvements: If building an ADU will trigger the need for any road or sidewalk improvements in your area, you may be asked to help pay for those. 

• Larimer County Road Impact Fees and Transportation Capital Expansion Fees: These will need to be paid before you can get a building permit. https://www.fcgov.com/engineering/tcef  

• Development and water supply fees (WSR): These will be due at the time the building permit is issued. Please contact our Utility Fee and Rate Specialists at (970) 416-4252 or UtilityFees@fcgov.com for more information or questions. Information on fees can also be found at: www.fcgov.com/development-fees. 

• Building fees: A plan review fee will be collected at the time of plans submittal on all work valued over $3,000. The building permit and any other applicable fees will be paid at the time the permit is issued. See Building Permit Fee Schedule. 

Is my property in a floodplain? If your property is in the Poudre River 100-year floodplain, you may not add any dwelling units. 
Is my property in this floodplain? Check our floodplain map.

Some zone districts have a minimum lot size and lot width. If your lot is smaller than these, an ADU would not be permitted.  

• An Accessory Dwelling Unit in your zone district is subject to a Basic Development Review. The decision maker on the project will be the Development Review Manager and/or the Director of Community Development and Neighborhood Services. 

• A neighborhood meeting is not required for an ADU in your zone district. If you would like to hold a meeting to notify your neighbors of your proposed plans, we can assist you with this request.  

• All documents submitted to the City in association with your ADU project are available to the public through our website.  

• Formal notice of your project is at the discretion of the Development Review Manager, and can include a posted sign, mailings to surrounding neighbors, and/or published notice in the Coloradoan and elsewhere.  

• When you submit your application, we will provide you with a roadmap that outlines what your specific steps will be to navigate the development review process.  

• When you submit your application, we will provide you with a project submittal checklist that you can use to ensure you are providing us all the items we will need to complete our review of your project.  

• All of your plans will need to be saved as PDFs. Please reach out if you or your contractor would like converting any AutoCAD files into flattened/optimized PDFs.  

• Project application submittals are accepted any day of the week, with Wednesday at noon being the cut-off for routing the same week.  

• There are fees associated with the Development Review Process, which you can find here. https://www.fcgov.com/developmentreview/fees 

• Please be aware that there may be extra fees from other departments and during the building permit process.  

• Please reach out to our Development Review Coordinators at DRCoord@fcgov.com if you have questions about any of the above. 

• Please see Article 2, Zone Districts, of the Land Use Code for more details on the specific rules for properties in your zone district.
• An Accessory Dwelling Unit in your zone district may be approved by the Director of the Community Development and Neighborhood Services Department. 
• If this property isn’t platted (in other words, isn’t shown on a previous subdivision plat map), then you will need to get a legal plat created by a licensed professional surveyor. 
• Some zone districts have a minimum lot size and lot width. If your lot is smaller than these, an ADU would not be permitted. Many zone districts do not have minimum lot sizes or lot widths.

•  ADUs may not be built in setbacks. Setbacks vary by zone district. Commercial zone districts do not have setbacks.  

• No permanent building may be built in an easement. Easements are areas set aside for things like utilities, emergency access or drainage. They are part of your property but have additional restrictions on them. When you submit your application, please show any known easements with their dimensions and purpose on your site plan. 

• You may only have one ADU on your property. 

• ADUs may not be used for Short-Term Rentals (Airbnb, VRBO, etc.)  

• An ADU can be attached to a primary structure (e.g., house), or detached and separate from the primary structure.  

• A detached ADU can be built behind a house, duplex or triplex.  

• A detached ADU must be at least 5 feet from all other buildings. If it is between 5 and 10 feet of another building, you will need to build it out of special materials to meet fire safety rules. You will also have limitations on the openings (windows, doors, etc.) that you can build in those walls.   

• The allowed floor area of the ADU will depend on several factors: 

• • The size of the primary structure (the house, duplex or triplex) 

  • Will the ADU be new construction or a conversion of an existing structure?
• The floor area will include all habitable and non-habitable spaces (e.g., garage floor area + ADU floor area both count toward the square footage totals). 

•  The floor area permitted in an attached ADU is: 

• ADU Height:  

  • A detached ADU can be up to 1.5 stories. In other words, a full first story with a second story no more than 40% of the area of the first floor. 

  • An attached ADU can be no taller than the primary building. 

• To the extent reasonably feasible, decks, entry doors, major entry access stairs, and major windows will need to face the existing primary building or the alley (if there is an alley). Any windows that overlook an abutting side or rear yard need to be minimized.  

• You will need to provide one on-site (off-street) parking space for the ADU, in addition to the parking already required for the primary building. Please show the parking spaces on your plans. 

• The ADU must have a full bathroom and a full kitchen.  

• There needs to be a walkway from the ADU to the street. The ADU’s address needs to be visible from where the walkway meets the public sidewalk (i.e., near the front of the primary building). This is so that any friends, emergency services and pizza deliveries can access the unit quickly and easily.  

• Buildings, structures and open spaces must be located on the property to trees and shrubs, to the extent reasonably feasible.  

• You can find all the detailed rules that will apply to the project in the Land Use Code, which you can find here: https://www.fcgov.com/planning-development-services/luc. 

• If your proposal is unable to meet all the rules, you may be able to ask for a Modification of Standard. The criteria for being granted a Modification of Standard are in Section 6.8 of the Land Use Code.  

• Following the Development Review Process, you will need to get a building permit. Find our current adopted building codes here: https://www.fcgov.com/building/codes 

• The Building Code treats an attached ADU and a Duplex the same (as a two-family dwellings in the current adopted in the International Residential Code). Building Code requirements include but are not limited to:  

  • 1-hour fire rated separation between units (including walls, ceilings, and 20-minute rated doors),  
  • Separate/independent heating systems,  
  • Minimum requirements for kitchens, and bathrooms,  
  • A separate swing-type exit door to the exterior, or a common shared fire-rated vestibule to the exterior.  

• If the attached ADU is new construction (but not including an addition to an existing structure), both units will need to be fire sprinkled in accordance with the International Residential Code.  

• You may need to upgrade the public electrical system to support the new dwelling unit. If modifications or relocations are necessary, you will need to cover the costs. Light & Power will determine the location of the nearest transformer and any needed upgrades after you submit your project application.  

• The Accessory Dwelling Unit will need its own electric meter and service lines. You will need to work with Light & Power to determine where the electric service and meter should go. You can find out more information about our metering requirements in our Electric Service Standards, Section 8, on our website: https://www.fcgov.com/utilities/what-we-do/light-power 

• In most cases, Light & Power will own, maintain and install the service for the ADU at your expense. In some cases, Light & Power will require the owner to provide the trench. If the service is more than 200 amps, the service will need to be owned, maintained and installed by the property owner.  

• If you build an ADU, you might need to provide a utility easement on the property so that a new transformer that can handle the additional load can be installed and accessed.  

• There will be fees for electric capacity, building site, service, and any necessary system modifications for the ADU. You can find an estimate of these charges and fees on our website. https://www.fcgov.com/utilities/business/builders-and-developers 

• The City of Fort Collins now provides high-speed fiber internet, video, and phone services. You can learn more about these residential services on our website. https://fcconnexion.com/residential/ 

• We also offer significant rebates to Fort Collins Utility customers for installing solar PV units through our Solar Rebate Program. Visit our website to learn more. www.fcgov.com/solar 

• Easements are areas on your property that are set aside for things like utilities, emergency access or drainage. These areas are part of your property but have additional restrictions on them. Our Engineering team will require you to provide any easements that may become necessary as a part of this project.  

• If there are already easements on your property, please show them on your site plan when you apply for the ADU project.  

• We will check your property to see if it has enough right-of-way along the street frontage. Please show this on your site plan when you apply too.  

• We will check to see if any road or sidewalk improvements will be needed in your area due to this project. If there are, you might need to help pay for these improvements.  

• We will also check that there are safe access points for vehicles, pedestrians, and cyclists to reach the ADU. If you have an alley behind your property cars might need to use the alley to reach the ADU. You may also be required to pave part of the alley.  

• If any sidewalks, driveways or ramps on or near your property don’t meet ADA standards, they will need to be fixed as part of your project.  

• You will need to pay Larimer County Road Impact Fees and Transportation Capital Expansion Fees before getting a building permit. You can find more information at: https://www.fcgov.com/engineering/tcef  

• Other important details that we provide for every development project: 

  • Any curbs, gutters or sidewalks that are damaged must be fixed before your project is completed.  
  • Public improvements must follow Larimer County Urban Area Street Standards, which can be found online. You can contact City staff if you need the link.  
  • Utility plans will be needed, and a Development Agreement will be recorded once the project is finalized.  
  • You will need a Development Construction Permit before starting construction work. 
  • The public right-of-way cannot be used for treating stormwater runoff.  
  • Any structures you would like to build in the public right-of-way would need to apply for an encroachment permit. Approval may not be granted. 
  • The public right-of-way cannot be used for staging materials or parking during construction.  

• If your project is near one of our protected natural habitats or natural features, you might need to hire a certified ecologist to conduct an Ecological Characterization Study. This helps us understand how your project might affect the environment. You may need to provide an un-developed buffer around those natural habitats or natural features. We can tell you if this Ecological Characterization Study requirement will apply when you submit your project application. You can reach out to our environmental planners at Planning@fcgov.com. 

• All landscaping plans you create for this project must be designed to incorporate water conservation materials and techniques, to the extent reasonably feasible. This will include using low-water-use plants and reducing bluegrass lawns. 

• You can find our Turf Conversion guidance document on this page: https://www.fcgov.com/developmentreview/environmental-planning-resources

• You can find the City’s easy-to-use Recommended Plant List here: https://www.fcgov.com/developmentreview/environmental-planning-resources 

• If you are planning to remove trees, please note that it is prohibited for any person at any time in the city to abuse or injure any wild bird or damage a nest with eggs or to injure the young of any bird. A professional ecologist or wildlife biologist is required to complete a nesting survey 5-7 days before conducting tree removal or trimming. If any trees will be removed, this text will need to be included on the tree mitigation plan and the landscape plan: “NO TREES SHALL BE REMOVED DURING THE SONGBIRD NESTING SEASON (FEBRUARY 1 TO JULY 31) WITHOUT FIRST HAVING A PROFESSIONAL ECOLOGIST OR WILDLIFE BIOLOGIST COMPLETE A NESTING SURVEY 5-7 DAYS BEFORE TREE REMOVAL OR TRIMMING TO IDENTIFY ANY ACTIVE NESTS EXISTING ON THE PROJECT SITE. THE SURVEY SHALL BE SENT TO THE CITY ENVIRONMENTAL PLANNER. IF ACTIVE NESTS ARE FOUND, THE CITY WILL COORDINATE WITH RELEVANT STATE AND FEDERAL REPRESENTATIVES TO DETERMINE WHETHER ADDITIONAL RESTRICTIONS ON TREE REMOVAL AND CONSTRUCTION APPLY.”  

• Poudre Fire Authority will need to make sure they have access to all exterior portions of any building.  Access is required within 150 feet of any exterior portion of a building and can be considered from any public street or private street meeting fire lane requirements.  If access within 150 feet cannot be achieved, the installation of an approved NFPA 13D fire sprinkler system can extend the access distance to 300 feet. 

• PFA will require a walkway from the main door of the ADU to the approved Emergency Access road.  This walkway is required to provide access for emergency personnel and equipment. 

• PFA will verify the water supply (Fire Hydrant) to the ADU.  A fire hydrant is required within 400 feet of the proposed ADU and the distance is measured along the approved path of fire apparatus access. 

• The ADU will need have its address posted in specific places that can help emergency services workers find their way to the building. The address numbers shall be a minimum of 4” in height with a minimum ½” stroke and shall be posted on a contrasting background.  Additional wayfinding signage may be required in order to provide emergency personnel direction to the ADU from the fire apparatus access road.   

• You can find all of our Fire Code information at this website: https://www.poudre-fire.org/programs-services/community-safety-services-fire-prevention/fire-code-adoption 

• Please check our interactive floodplain map to determine if floodplain requirements may apply to your property. https://gisweb.fcgov.com/HTML5Viewer/Index.html?viewer=FCMaps&LayerTheme=floodplains 

• Any ADU to be located in a City or FEMA regulated floodplain should contact floodplains@fcgov.com to discuss permitting requirements. 

• If your property is located in the Poudre 100-year floodplain, no new residential units (including ADUs) will be allowed.  

• In most cases, Historic Review will not be required if you are building an ADU on a residential property with a detached house as the primary dwelling unit.  

• Historic Review may be required if you are hoping to build an ADU and the primary building is a duplex, triplex, or a detached house that contains a non-residential land use (dentist, insurance agency, architect office, candy shop, etc.). In these cases, Historic Review would be required if the building is at least 50 years old or is designated as a historic resource. You can find out if your property is designated as historic here: https://www.fcgov.com/historicpreservation/fort-collins-landmarks.   

• Stormwater can check which subdivision or neighborhood your property belongs to. Your project must follow the drainage design approved for that neighborhood. If your property isn’t in a neighborhood that has an approved plan, it must follow the designs in the Master Drainage Plan for your area and the Fort Collins Stormwater Criteria Manual. You can find these criteria here: https://www.fcgov.com/utility-development. 

• If your project proposes to change the approved drainage plan, you will need a drainage letter and construction plans to be prepared by a Professional Engineer registered with the State of Colorado. These plans must show existing and proposed drainage patterns, where stormwater runoff will go (stormwater outfall), how to handle extra runoff on neighboring properties, and the areas that don’t absorb water (impervious areas). 

• You will need to show the existing and proposed impervious areas with a table summarizing the areas with your project application. If the improvements create more than 1,000 square feet of new impervious area, stormwater quality treatment will be required for those new areas. Options could include directing downspouts into landscaped areas, disconnecting impervious areas, installing rain gardens, and using permeable pavers. 

• You will need to provide a drainage letter and construction plans (site plan, grading & drainage plan, and utility plan) with your application. These will need to be prepared by a Professional Engineer registered in the State of Colorado. These documents will need to: 

  • Show the existing and proposed drainage patterns,  
  • Identify where site runoff is going (stormwater outfall),  
  • Address any need to mitigate additional runoff directed onto neighboring properties (in some cases offsite easements may be required), and  
  • Show the final site impervious areas (buildings, pavement, driveways, etc.).  
• Drainage requirements and development fees are based on new impervious area added with the project. More information on our fees can be found at: https://www.fcgov.com/utilities/business/builders-and-developers/plant-investment-development-fees.  

• Please feel free to reach out with any questions to: WaterUtilitiesEng@FCgov.com.  

• All plans must be based on the NAVD88 vertical datum. Before starting any surveying or design work, please make sure your consultants are aware of this requirement. Please contact our office for the latest Benchmark Statement format and City Vertical Control Network information.  

• Technical services has specific naming, surveying and mapping conventions that will need to be followed in order to legally vest a project.  

• Traffic Operations requires a Traffic Impact Study for some developments. Typically, an ADU would not require a Traffic Impact Study, but in order to waive the study you will need to submit a worksheet with your application. The worksheet is called a Transportation Worksheet (Attachment “C”). Here is a link where you can find the worksheet and learn more about the Traffic Impact Studies we require. https://www.larimer.gov/sites/default/files/uploads/2021/ch04_transportation_impact_studies_0.pdf 

• When you submit your application, we will review the access points to the property to make sure they meet our standards. The number of access points (e.g. driveways) we allow for one property will vary depending on how your streets are classified (arterial, collector, local, etc.), but in most cases we will want any access to an ADU to be shared with the driveway to the existing building on the site.  

• If the property currently has more access points than are allowed, one or more may need to be eliminated. Closure of an access point may required you to construct the curb, gutter and sidewalk along the street.  

• Your property may be within the City of Fort Collins water and sewer service areas, however there are several water and sewer providers within City limits. You can check this map to find out who provides your water service and sewer service and how to contact them.  https://gisweb.fcgov.com/HTML5Viewer/index.html?Viewer=Utility%20Districts 

• The information below is specifically for Fort Collins Utilities customers. If you’re served by a different utility, they might have similar rules for your project, but you’ll need to check with them.  

• If you are in the Fort Collins water utility district, before you submit your application, please contact us at WaterUtilitiesEng@FCgov.com for information about the existing sewer infrastructure on and near your property. The City can provide you with information about the closest public sewer main (often in a nearby street) and private sewer service (from the water main to the building) to your site.  

• Fort Collins Utilities water and/or sewer services to an existing residential building can be extended to one additional structure. This requires a covenant agreement for the property that says the lot may not be divided so the extra structure is on a separate lot. If the accessory structure is an ADU, you will need to pay additional water and sewer fees. 

• Development and water supply fees (WSR) will be due at the time the building permit is issued. Please contact our Utility Fee and Rate Specialists at (970) 416-4252 or UtilityFees@fcgov.com for more information or questions. Information on fees can also be found at: www.fcgov.com/development-fees. 

• When you submit your application, you will need to include a utility plan showing how the water and sewer services will be extended to or otherwise provided to the new structure. Generally, this plan is prepared by a Colorado Professional Engineer.  

• On small sites, it can be difficult to find space to meet rules about how far water utilities need to be located from other things.  

• For your reference, minimum water and sewer service separations are: 

  • More than 10 feet between water and sewer services 
  • More than 6 feet between trees and water or sewer services 
  • More than 4 feet between shrubs and water or sewer services 
  • More than 10 feet between storm drain pipes and other utilities 
  • Service lines of the same type may be placed together in the same trench but they will need to be separated by at least 3 feet. 
• Other utilities, such as gas, electric and communications will also have spacing requirements and will need space on the site. Last, please remember that there may be service lines on neighboring properties and you will need to keep your utilities separated from those as well.