Pitkin County Colorado’s “The Matrix” energy code addendum

Take the blue pill, go build somewhere else, the story ends, you wake up in your bed and believe whatever you want to believe. Or, you take the red pill, you stay in Wonderland, and we dive down the rabbit-hole…

Link to Energy and Land Use Code Information Page

Link to The Matrix

Pitkin County, Climate Zone 7,  has added a residential energy conservation addendum for new construction and remodels, on top of the 2015 IECC requirements. Why? Basically, it is to bring construction in line with the Climate Action Plan. PitCo sponsored some fascinating research. One study says that about 70% of GHG (Green House Gas) emissions in Pitkin County are from the built environment. Another study predicts that more houses will be built in Pitkin County. Yet another study tracked the energy consumption of 900 houses for four years then, consumption was compared to house size. One might expect a 10,000 square foot house to have ten times the consumption of a 1,000 square foot house, but the study shows that the consumption of an average 10,000 square foot house was closer to thirty times the consumption of the 1,000 square foot house! How is this possible? It is because as the houses get bigger, they tend to get more luxurious. This means the house is more likely to be packed with energy-consuming amenities like; high percentages of glazing, large interior volumes, snowmelt, pools, hot tubs, saunas, conditioned wine cellars, conditioned garages, audio-visual-security systems, humidity control, air conditioning, multiple redundant appliances, steam showers, multiple redundant shower heads, heated toilet seats and towel bars and a plethora of other electric-powered gizmos.

The addendum has been come to be know as “The Matrix” because of the table format that outlays the requirements. There are two tiers of compliance; one for houses under 5,750 square feet and one for those over. The Matrix also makes a differentiation between houses that have more and less than 15% glazing. There are special requirements when working with existing construction, including; an energy assessment of the existing structure, air sealing improvements and occupant, crawlspace and attic ventilation compliant with current code.

What does this mean for the Architect?

  1. Significant mandatory requirements; 50%-75% engineered lumber, insulated headers, 24” stud spacing, insulated corners or alternate construction, glazing U-factor of .28, ENERGY STAR appliances, mechanical commissioning of complex systems, sealed ductwork, garage exhaust fans, rough-in for PV and thermal solar and EV charging outlets.
  2. Any house with more than 15% of its walls glazed will be required to use the 2015 IECC UA trade-off (REScheck) or ERI compliance (HERS Rating) alternatives; no prescriptive submittals.
  3. Any house larger than 5,750 square feet will be required to use the 2015 IECC ERI compliance alternative; no UA trade-off or prescriptive submittals.
  4. Get in the habit of retaining an Energy Rater; early in the process.

What does this mean for the builder?

  1. Learn to work with efficient framing, SIPS and/or continuous insulation.
  2. Get in the habit of working with an Energy Rater; through the whole process.

Confluence Architecture & Sustainability can provide all the documentation, modeling, testing and certification required to navigate the Matrix.

Aspen’s energy code amendments could not be more different from Pitkin County’s Matrix. Click here to read about those.

Jump to Aspen Colorado’s energy conservation code compliance page…

Jump to Basalt Colorado’s energy conservation code compliance page…

Jump to Carbondale Colorado’s energy conservation code compliance page…


Aspen Colorado’s energy code amendments

Spoiler Alert! The City of Aspen has customized their energy code. This blog is about the residential code, I’ll tackle the commercial modifications later.

See the amendments text adoption here…Ordinance 40-2016

Link to Aspen’s Community Development Department…

What are the significant changes?

  1. The first change to the code drops the prescriptive allowable fenestration U-factor to .28.
  2. If submitting under the total UA trade-off compliance option, you will be required to go 2% beyond the passing line, in order to compensate for the fenestration glazing U-factor change.
  3. The option for exhaust-only occupant ventilation and air-cycler systems have been taken away, as balanced heat recovery systems are made mandatory. The HRV or ERV must have an efficiency of at least 65% and its fan powered by an EMC motor. All fans are required to meet a higher standard of efficacy; CFM/watt.
  4. Air sealing is still required, but infiltration (blower door) testing is not required.
  5. Mechanical sizing (ACCA Manual J calculations) is not required.

Here’s the interesting part, the City of Aspen, Climate Zone 7, has sought to simplify the code by deleting the IECC ERI compliance alternative and replacing it with their own version. It’s called the Simplified Equivalent Compliance Alternative. Dwellings must meet the following criteria to comply with this alternative.

  1. Equivalent space cooling energy. The ratio of the air conditioning capacity to conditioned space is less than or equal to 12,000 Btu/hour per 1,000 square feet.
  2. Equivalent space heating energy. The ratio of the space heating system capacity to floor area of conditioned space is less than or equal to 32,000 Btu/hour per 1,000 square feet.
  3. Equivalent hot water. The distance from the hot water supply outlet to hot water pipe to the hot water entry to a room where hot water is used shall be no more than 10 feet. This shall apply to the kitchens, bathrooms with showers or tub, and rooms with a clothes washer.
  4. Equivalent lighting. Lamps over 15 watts shall be CFL, LED, or have an efficacy not less than 90 lumens per watt. Or, at least 90% of the lamps or fixtures shall have an efficacy not less than 75 lumens per watt.

This code change deletes equipment sizing, infiltration testing and energy modeling; the very tenets of the energy rating paradigm. I like the simplicity, but I fear it is too simple. I guess time will tell how Aspen fairs under this code.

Confluence Architecture & Sustainability can provide third-party insulation and air barrier inspections, and certification of compliance with the other provisions of this code.

Pitkin County’s “Matrix” could not be more different from Aspen’s energy code amendments. See link below…

Jump to Pitkin County Colorado’s energy conservation code compliance page…

Jump to Basalt Colorado’s energy conservation code compliance page…

Jump to Carbondale Colorado’s energy conservation code compliance page…