Boulder County Building Publications
Ignition Resistant Construction - B37

Planning Review Requirements

Ground-mounted small wind electric systems require Expedited Site Plan Review (ESPR) approval in all zone districts provided they do not exceed the maximum height of the zone district. Ground-mounted systems will be reviewed through the Site Plan Review (SPR) process if they are proposed to exceed the height of the zone district, up to 80 feet. Small wind-powered energy systems cannot exceed 80 feet in height.

Roof-mounted small wind-powered energy systems are allowed without a planning review process provided the system does not exceed the roofline by five feet or the maximum height of the zone district by five feet. Larger roof-mounted systems (up to 15 feet) must be reviewed and approved through the ESPR process.

The cost for all planning reviews for residential scale wind turbines is $100. To schedule a Pre-application Conference with a Planner, call 303-441-3930.

The ESPR or SPR process must be completed before a building permit application can be processed. Once your ESPR or SPR application has been approved, utilize the checklists in this handout to help prepare and submit your building permit application.

Building Plan Submittal Requirements

Per Article 694 of the 2023 NEC (National Electrical Code), Small Wind Electric Systems are reviewed by the county electrical inspectors.

The following checklist, along with the required items, is to be submitted with your building permit application. Each item on the list is to be marked to verify that it is part of the submittal. Incomplete information may result in plan rejection or delay in the approval of your project.

Provide the following information:

• All construction drawings must be submitted in PDF format at the time of your online building permit application Boulder County Permit Records & Online Application Submittals.
• Include the proposed wind electric system capacity in watts, and whether the system is a stand-alone or interactive-grid-tied system.
• Any documents or information required as part of a Site Plan Review approval.

Site Plan – Equipment Outside a Building

Please show the following on the site plan:

• Location of all disconnects.
• Location of all batteries.
• Location of all rectifiers, wind generator turbine(s).
• Location and connection of all grounding electrode conductors.
• Clearances around all equipment.
• Dimensions between equipment and structures.
• Dimensions between equipment and property lines.
• Proposed height of the wind-powered structure from grade to the highest part of the equipment.

Note: See the Pole or Ground Mounted Turbine Section for additional site plan requirements.

Floor Plan – Equipment Within a Building

• Show the location of all disconnects.
• Show the location of all batteries.
• Show the location of all rectifiers, inverters, & charge controllers.
• Show the location and connection of all grounding electrode conductors.
• Show the location of all equipment within structures.
• Label the use of the room in which the equipment is placed.
• Show clearances of the equipment.

Wiring Requirements

• Provide a one-line diagram that includes the following information:
• Label whether the system is stand-alone or interactive-grid-tied.
• Conductor sizes.
• Conductor insulation types (i.e. THHN, THWN, direct burial cables, etc.)
• Conductor material (i.e. copper/aluminum).
• AC or DC load identifier labeling.
• Conduit sizes.
• Conduit material (i.e. non-metallic, EMT, etc.)
• Over current device ratings.
• Existing and new panel amperage ratings (buss ratings).

Equipment Requirements

Provide product listing sheets for all equipment with the following information:

• Wind turbine specifications and documentation showing all equipment as listed products.
• Fuse ratings.
• Rectifier and inverter output current ratings.
• Rectifier and inverter UL listings.
• All associated documentation (i.e. batteries, inverters, rectifiers, disconnects, charge controllers, over-current devices, etc.).
• Method of grounding for live current carrying parts and equipment grounding for the metal parts of towers and supports of the wind turbines.
• Nacelles and other control equipment installed in exterior areas shall be listed and labeled for exterior installations and use.

Note: Lightning protection may be required to bond to the grounding electrode system.

Turbines

Roof Mounted Turbines

Provide the following information:

• Provide structural construction documents from a Colorado Registered Structural Engineer approving the design for the anticipated dead loads and wind loads for the location. For existing structures, the engineer’s approval should include an assessment that the existing roof structure is capable of supporting the added weight and lateral loads imposed on the roof. For new construction, complete construction documents are required for the full structure, from the top to foundation, and all site-specific design loads and conditions.
  • A statement of special inspections is required and shall list all continuous special inspections, periodic special inspections, and special inspections otherwise noted by the engineer.
  • The engineer must reference the required wind and snow loads for the site. See the current Boulder County Ground Snow Load Map and Wind Speed Map to find the wind/snow loading in the area of the proposed construction.
• For flat roof installations provide method of roof repair for roof penetrations.

Pole or Ground Mounted Wind Turbines

Provide the following information:

• Expedited Site Plan Review approval
• Site plan to include the following:
  • Location and height of wind turbine support on property.
  • Dimensions of structure location to the property lot lines and easements including any existing utilities.
  • Dimensions for the distance of the proposed structure to other structures, and other lot improvements, on the property.
  • Reference a cardinal direction for orientation.
• Provide structural construction documents from a Colorado Registered Structural Engineer referencing all anticipated design loads including but not limited to the wind loads and soil bearing capacity for the location. A statement of special inspections is required and shall list all continuous special inspections, periodic special inspections, and special inspections otherwise noted by the engineer.
  • Foundation and structure designs are required.
  • A statement of special inspections is required and shall list all continuous special inspections, periodic special inspections, and special inspections otherwise noted by the engineer.
  • The engineer must reference the required wind and snow loads for the site. See the current Boulder County Ground Snow Load Map and Wind Speed Map to find the wind/snow loading in the area of the proposed construction.

Pole or Ground Mounted Wind Turbines

Provide the following information:

• Expedited Site Plan Review approval
• Site plan to include the following:
  • Location and height of wind turbine support on property.
  • Dimensions of structure location to the property lot lines and easements including any existing utilities.
  • Dimensions for the distance of the proposed structure to other structures, and other lot improvements, on the property.
  • Reference a cardinal direction for orientation.
• Provide structural construction documents from a Colorado Registered Structural Engineer referencing all anticipated design loads including but not limited to the wind loads and soil bearing capacity for the location. A statement of special inspections is required and shall list all continuous special inspections, periodic special inspections, and special inspections otherwise noted by the engineer.
  • Foundation and structure designs are required.
  • A statement of special inspections is required and shall list all continuous special inspections, periodic special inspections, and special inspections otherwise noted by the engineer.
  • The engineer must reference the required wind and snow loads for the site. See the current Boulder County Ground Snow Load Map and Wind Speed Map to find the wind/snow loading in the area of the proposed construction.

Rough Inspections

Boulder County will perform a rough inspection on the small wind electric system. This inspection should be scheduled after the installation of the supporting framework for the wind turbine has been installed to the footings and/or roof mounting supports, the bonding and grounding is installed, and the nacelle, rectifier, charge controller, and/or inverter equipment may be in place. Open trenching for the supply conductors from the wind electric system support structure to the service equipment should also be inspected at this time to verify the correct trench depth and the type and size of the conductors. In addition to the rough inspection, at the completion of the work, the Building Safety and Inspection Services team will also conduct a final inspection. Please call for these required inspections when ready.

If you have any questions, contact Boulder County Building Safety and Inspection Services:

Email: Building Inspectors at BuildingInspectors@bouldercounty.gov

This Publication is Printable