When a Tree Related Permit Is Required
Tree Maintenance: If you are planting, treating, or pruning trees and will be occupying right-of-way space for more than thirty minutes, you must submit a Temporary Encroachment Permit Application.
Tree Impact Permit Application: Required when any of the proposed site improvements could potentially impact a tree or trees and the tree/s meet the following size thresholds:
- Woody shrubs: 3 inches and greater in diameter.
- Coniferous trees: 4 inches and greater in diameter.
- Deciduous trees: 6 inches and greater in diameter.
Use this link for detailed information on how to properly measure your tree.
Use these quick reference guides on site improvement planning and tree value.
If your permit application is associated with wildfire mitigation, please review our Wildfire Mitigation Policy and Ignition Resistant Tree Guide.
How Applications Are Evaluated
All tree removal and root zone impact requests are reviewed by the Parks and Open Spaces department using the Tree Assessment and Valuation Framework. The City Forester and Permit Coordinator evaluate:
- Tree condition and safety
- Potential impacts to surrounding trees and site conditions
- Opportunities for tree retention, protection, or replacement
- Whether the work is connected to development or site changes
- The applicant must indicate whether they have plans to submit a building permit, demolition permit, grading permit, or other site improvements within the next three (3) years.
Tree Mitigation Fees May Be Charged | Tree Mitigation Fees May Be Reduced or Waived |
| Construction of new buildings or additions | Planting replacement trees on site (See drought tolerant and ignition resistant species guides) |
| Demolition, redevelopment, and changes in land use | Documented hazards or public safety risks |
| Grading, excavation, or site reconfiguration | Wildfire mitigation or defensible space work |
| Installation of utilities and other infrastructure | Forest health or site capacity improvements |
| Creation of construction access, staging areas, or driveways | Watershed protection and stormwater management |
| Other site improvement activities | APCHA-regulated or City-sponsored affordable housing projects |
Next Steps
Click here to set up an account and apply for a permit.
Use this excel sheet to estimate the potential mitigation value of trees proposed for development related removal. Funds collected through tree mitigation are reinvested directly into Aspen’s urban forest. These dollars support the planting of new trees, the care and maintenance of existing trees, and long-term forest health projects within City parks and public rights-of-way. Your contribution helps ensure Aspen’s tree canopy remains vibrant, resilient, and well cared for.
After you submit an application, the City Forester or Permit Coordinator will complete a site visit to assess your trees.