Based on the provided guide, Denver’s zoning and building requirements for Accessory Dwelling Units (ADUs) in 2026 focus heavily on structural safety, frost protection, and soil stability.

Key considerations for 2026 zoning and building updates include:

• Frost Depth Requirements: Denver building codes mandate a 36-inch frost depth. All pier systems, including helical piers, must extend below this level to prevent frost heave and ensure structural safety.
• Soil-Specific Engineering: Due to Denver’s expansive clay soils, zoning and engineering standards often require specialized foundation work. This may include helical pier stabilization or screw piles to reach load-bearing strata, particularly for garage and basement conversions.
• Structural Reinforcement: New living loads must be supported by reinforced foundations. For basement conversions, codes may require tiebacks to stabilize below-grade walls against lateral soil pressure, especially when retaining walls exceed specific heights during excavation.
• ICC-ES AC358 Certification: Structural components like helical piers should meet ICC-ES AC358 certification, which involves rigorous load testing and real-time torque verification to comply with high safety standards.
• Egress and Safety: Requirements for egress windows and other safety features vary by specific zone and are essential for converting existing spaces into compliant living areas.

Because no two projects are alike and local requirements can vary by specific neighborhood or property condition, it is recommended to schedule a site-specific inspection and consult a licensed structural engineer for a definitive project design.