Building in Boulder: A Complete Guide

Learn more about building in Boulder, Colorado to begin your project.

The City of Boulder & Boulder County

Properties located within the City of Boulder limits and those located in unincorporated Boulder County are not governed by all of the same building regulations. It is important to understand if your property is located in the City of Boulder or Boulder County and which rules apply before starting any type of design/construction project: what might be allowed in the City, may not be allowed in the County, and vise versa.

In comparing the City and County requirements, there is no “better”, only “different.” Each jurisdiction requires their own forms and even different consultants to complete a building project to code.

It is critical to know the required steps and have the proper guidance for getting the information completed and documents in the format each official requires to expedite the process for obtaining a permit. Incomplete documentation can significantly stall the permitting process and therefore lengthen the timeframe of your project.

One of your first steps in the process is to know whether or not your property is in the City of Boulder or Boulder County.

Boulder County:

If you believe your property is located in Boulder County, you should be able to locate it on the Boulder County assessor’s website here. If the property address comes up with “unincorporated” behind it, it is a Boulder County location and you will have access to additional information on the property.

The City of Boulder:

If you believe your property is within the city, you will want to begin the process by clicking this link – the City of Boulder’s Zoning Map. Here, you can enter the address of your property and confirm that it is within the city limits.

Property Zoning

Whether the property is located in the City of Boulder or Boulder County, it will be placed in a zoning district. Knowing the zoning district for your property is essential. The zoning classification for a property determines the “rules” for that property such as:

  • Building Set-Backs
  • Height Limits
  • Allowable Floor Area
  • Allowable Lot Coverage
  • Whether more than one building is allowed on a property
  • How the site can or cannot be accessed

Additionally, for your own knowledge, you will want to be familiar with neighboring zones. As you begin to plan the home of your dreams it is important to not only know what is there currently, but what the municipality may allow to be built there in the future. These same links will further help you understand the zoning of your prospective lot.

Boulder County Assessor
City of Boulder’s Zoning Map

City of Boulder: Important Requirements

As you can imagine, the City of Boulder properties generally tend to be smaller and therefore population is denser. Many of the required documents, calculations and submittals specific to the City of Boulder relate to perceived density.

Floor Area Ratio (FAR)

This is the maximum floor area you are allowed to build on any given site in the City. It is calculated using a formula created by the City. 

Maximum Allowable Coverage

This is the maximum area you are allowed to cover any given site in the City. It is calculated using a formula created by the City. 


The City is sensitive to very large new structures being built next to smaller scale structures throughout the town. This requirement focuses on the height of side walls immediately adjacent to neighbors properties and gives you the example of how the City would like you to document your compliance. 

Bulk Plane

Similar in intent to the compatibility requirement, this requires you to document appropriate massing of the project. 

Solar Analysis

With our Colorado sunshine and beautiful views, Boulder is sensitive to the rights of everyone to enjoy these. A solar analysis is therefore required on every new project in the City to prove the new structure will not block sun or views from adjacent properties. 

Energy Requirements & Documentation of Compatibility

The City of Boulder has well defined criteria for building materials and practices resulting in buildings of superior energy efficiency. A Home Energy Report (HERS) or equivalent documentation is required at the time of permit submittal to confirm the project meets the City’s energy standards. 

Historic Districts

There are several areas in the City of Boulder determined to be Historic Districts and each area has their own set of standards and requirements for new construction and/or additions/remodels. There will be additional documentation required when building in these areas, so it is advisable to go to the City of Boulder website for more information. The requirements listed below is a sampling of specific pieces of documentation required for Building Permit submittal within the City of Boulder. They are representative and do not include the full documentation requirements.

Boulder County: Important Requirements

The first difference between the City and County of Boulder process is that the County has a couple of additional steps in the process before they will accept any documentation for building permit. The first step is a required pre-application meeting which is by appointment only and can be scheduled using the link here. It should be noted that these appointments can fill up quickly and are often not available for several weeks. At this meeting, a County planner will review all regulations specific to the property with the owner or Owner’s agent (i.e. – setbacks, height limitations, maximum square footage, easements, etc) and will discuss the proposed scope for the intended project on the property. Once this step is completed, the project is cleared to be scheduled for Site Plan Review (or a Site Plan Review Waiver if it qualifies). This submittal is also by appointment only and will be scheduled with Boulder County directly via phone 303.441.3930. For a description of the purpose behind this as well as the requirements for this submittal go to:

Be advised that this step is required for most projects* and can add up to 2 months to the entire permit submittal process (depending how backed up the County planners happen to be).

Maximum Allowable Floor Area

Like the City of Boulder, this is the maximum floor area you are allowed to build on any given site in the County. It is called the presumptive size and is determined as a percentage (125%) of the median square footage of a property’s “neighborhood”. Any given “neighborhood” is defined by the County and in general terms encompasses adjacent properties within a 1500’ radius of the property in question (there are many exceptions to this). Since ‘neighborhoods’ are defined by the County, information related to allowable floor area as well as other site specific information need to be requested directly through the County.

Wildfire Designation

Boulder County has well defined wildfire zones which determine much of the detailing and allowable materials on a project. It is important to understand in which wildfire zone a project is located. Please note that all residences over 3,000 sq.ft. are required to be fully sprinklered.

Maximum Allowable Lot Coverage

This is similar to the City’s requirement but uses a different formula as well. It is still intended to calculate the area that will be covered by your proposed building.

Energy Requirements & Documentation

Boulder County has specific requirements for Energy Code Compliance based on the size and type of the project. For most projects, an energy consultant will be required to provide professional documentation to the County indicating compliance with current requirements.


Many properties in Boulder County do not have water, sewer, electricity and/or gas currently run to the property. Determining the types of utilities and which company is the provider for a particular property is important and information the County requires before permit submittal. For additional information contact the Boulder County Planning Department or go to their website. The requirements listed below is a sampling of specific pieces of documentation required for Building Permit submittal within Boulder County. They are representative and do not include the full documentation requirements.

The Right Team of Professionals

As is evident from the information above, whether you are planning to build in the City of Boulder or unincorporated Boulder County, the process can be confusing and the amount of documentation required overwhelming. With the type of information the local jurisdictions require, there are professionals required on every project in addition to the architect and builder to get the job done. At a minimum, when building in Boulder, you should have the following professionals as members of your team:


The architect generates the project design. In addition to this, the architect is responsible for coordinating the other professionals on the team, making sure their information is complete and documented appropriately. The architect will issue the Request for Proposals from these individuals and review their proposals with the Owner.

General Contractor

A General Contractor licensed in the jurisdiction where the project is to be built is required for new home construction. Both the City of Boulder and Boulder County require specific licensing for general contractors in addition to the basic licensing requirements of the State of Colorado.

Structural Engineer

Both the City of Boulder and Boulder County require fully design structural drawings signed and stamped by a licensed engineer in good standing in the State of Colorado.


All projects in City of Boulder and Boulder County are required to have a professional survey completed – signed and stamped by a licensed surveyor.

Soils Engineer

All projects in City of Boulder and Boulder County are required to have a soils report completed and submitted with the documentation at the time of Building permit submittal.

Energy Rater

All projects in City of Boulder and Boulder County are required to have energy analysis reporting completed and documented by a professional energy rater.
Fänas Architecture has successful on-going working relationships with professionals in all areas of the building industry. We pride ourselves on assembling the perfect team for every project: a team that not only works well together, but works well for the client, ensuring the project is not only designed perfectly, but documented and built as efficiently as possible.

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