What are the Low Nox Furnace Requirements for Colorado in 2026?

Based on the standards established by Colorado HB23-1161, new furnace installations must meet strict emission requirements starting January 1, 2026. These regulations mandate that new gas furnaces comply with ultra-low NOx thresholds or Energy Star standards to curb nitrogen oxide pollution and support state clean air goals.

Key details of the 2026 requirements include:

Emissions Reduction: The mandates require manufacturers to meet thresholds that can reduce pollutants by up to 80 percent compared to older furnace models.

Regional Enforcement: In the Denver Metro area, the 2026 rules will enforce immediate upgrades for units that are non-compliant. Areas like Castle Rock and Colorado Springs are also aligning with these state standards, focusing on new construction and local quality initiatives.

Financial Considerations: While the advanced technology may increase upfront costs by 20 to 30 percent, homeowners can access state rebates that offset up to 20 percent of installation costs. Average installation costs for compliant 80 percent AFUE models are estimated to range between $4,500 and $8,500 depending on the specific region and available incentives.

Compliant Brands: Available low-emission brands that meet these upcoming standards include Trane, Carrier, Lennox, Goodman, York, and Rheem.