Amended energy code has been adopted- goes into effect July 1st 2025

2021 IECC (International Energy Conservation Code) plus the state Electric Ready and Solar Ready Code for Residential and Commercial Buildings has been adopted.

Residential

The chart below is the crux of understanding the energy code compliance.

Additional energy efficiency package:

Prescriptive projects must show a Total UA calculation of +5% or better.

ERI projects must show required score +5%

HERS projects must choose ductless heat pump or reduced infiltration rate (3 ACH50) + balanced ventilation

Balanced ventilation, higher heating, cooling and hot water production efficiency are already mandatory.

Some other things to note…

The REBP (Residential Efficient Building Program) has been replac3ed with the language in Chapter 36 SUSTANABLE BUILDING CONSTRUCTION PRACTICES.

Carbondale is back to considering themselves climate zone 5.

Minimum air impermeable insulation for condensation control as been increased to R30.

All insulation must be installed to HERS Rater’s grade 1 satisfaction, or is has to be torn out and redone. This includes foundation CI coming all the way up the top of the slab, in all locations (with exception of between the house and garage). This insulation is required to be protected above grade and up to 6″ below grade.

All garages have to be insulated like a heated space.

Hot water efficiency must be at least 90%

Gas fired heating or cooling equipment shall have an efficiency rating of 92% AFUE or better.

All electric Air Conditioning units shall be 15 SEER minimum.

All Heat Pumps must be designated for “Cold Climate” and shall have a HSPF rating not less than 10.

Renovation/addition

>1,750 sf of renovation or addition must just follow the new construction sections.

Multi-family

See text…

Commercial

See text…

Jump to Energy Conservation Code Hub for; the western slope of Colorado; Aspen, Telluride, Mountain Village, Town of Snowmass Village, Basalt, Carbondale, Pitkin and Eagle County…