Oregon HVAC Legislation, Codes, and Guidelines

Oregon HVAC Building Codes and Legislation

Oregon regulates heating, ventilation, and air conditioning (HVAC) systems through a series of state-specific specialty codes. These codes are updated periodically to incorporate modern standards, energy efficiency requirements, and safety protocols. As of April 2026, the primary codes governing mechanical systems in the state include the 2025 Oregon Mechanical Specialty Code (OMSC) and the 2023 Oregon Residential Specialty Code (ORSC).

The 2025 OMSC, which became mandatory on April 1, 2026, is based on the 2024 editions of the International Mechanical Code (IMC) and the International Fuel Gas Code (IFGC), with specific Oregon amendments. For residential construction, the 2023 ORSC provides the governing standards. Recent legislative and regulatory updates have introduced significant changes, including new requirements for heat pumps in certain new residential construction projects where split-system air conditioning is installed, aimed at improving energy efficiency and reducing long-term utility costs for homeowners.

Primary Regulatory Agencies

The administration and adoption of these building codes are managed by the following state entities:

Resources to Learn More

Select a County Below to Learn More About That Jurisdiction in Oregon

Permit rules operate within the above structure but can be nuanced at the county or municipal level. Select your local area below for specific ordinances, local codes, and direct links for your locality Building Department.