Carbondale’s new Energy Code adoption

Posted on by

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…

 

Pitkin County, Colorado’s energy code addendum

Posted on by

Updated energy code has been adopted- goes into effect April 27th 2025.

State electric ready code has been adopted too.

Link to 4-27-2025 adoption text

New construction:

The prescriptive 2021 IECC table has been modified. Most notably .27 U-factor windows mandatory.

New Performance path/ERI/HERS goals: 2021 HERS-PV / HERS+PV

Note that off-site solar is allowed in some circumstances.

All PV requires an energy storage system of 5 kWh or 25% of annual production, whichever is greater.

All projects are requested to provide a release of utilities provider information so usage can be tracked.

Additions:

New building envelope assemblies that are part of the addition shall comply with Section R402. (projects can still use UA trade-off)
Additions of 500 square feet or more of floor area shall be divided into two categories and include
the following additional requirements:
Tier 1 dwellings (0-3,250 sf, existing + new): shall be required to conduct a pre-construction
Home Energy Assessment by a certified third party on the existing building. A comprehensive
report of the assessment shall be submitted with the building permit application and include the
following criteria:
1. Annual Energy Consumption
2. Existing Building Envelope Air Leakage Test
3. Recommended Building Envelope Upgrades
4. Recommended HVAC Upgrades
5. Recommended Water Heating Upgrades
6. Recommended Health and Safety Upgrades
7. Recommended Lighting and Appliance Upgrades
A post-construction Air Leakage Test shall be performed on the existing building and addition prior
to Final Building Inspection demonstrating a 15% reduction in air leakage.

Tier 2 dwellings (3,251 sf and above, existing + new): shall be required to conduct a pre-construction
Energy Rating Index Assessment performed in accordance with ANSI/RESNET/ICC
301, on the existing dwelling, as well as a projected rating including the addition to document any
level of improvements made and to ensure that the home does not perform worse than it did prior to
the addition in accordance with Section R502.1. In addition to the Energy Rating Index, a
comprehensive report of the assessment shall be submitted with the building permit application and
include the same criteria as in Tier 1. A post construction assessment shall be submitted prior to
Final Building Inspection to demonstrate compliance. A post-construction Air Leakage Test shall
be performed on the existing building and addition prior to Final Building Inspection demonstrating
a 15% reduction in air leakage.
Exception: New envelope assemblies in additions less than 500 square feet in area are exempt from
the requirements of Section R402.4.1.2, R402.4.1.3.

Alterations:

Building envelope assemblies that are part of the alteration shall comply with Section R402. (projects can still use UA trade-off)
Alterations of 500 square feet or more of floor area shall be divided into two categories and include
the following additional requirements:

Tier 1 dwellings (0-3,250 sf): shall be required to conduct a pre-construction Home Energy
Assessment by a certified third party on the existing building. A comprehensive report of the
assessment shall be submitted with the building permit application and include the following
criteria:

1. Annual Energy Consumption
2. Existing Building Envelope Air Leakage Test
3. Recommended Building Envelope Upgrades
4. Recommended HVAC Upgrades
5. Recommended Water Heating Upgrades
6. Recommended Health and Safety Upgrades
7. Recommended Lighting and Appliance Upgrades
A post-construction Air Leakage Test shall be performed on the existing building and alteration
prior to Final Building Inspection demonstrating a 15% reduction in air leakage.

Tier 2 dwellings (3,251 sf and above): shall be required to conduct a pre-construction Energy
Rating Index Assessment performed in accordance with ANSI/RESNET/ICC 301, on the existing
dwelling, as well as a projected rating including the alteration to document any level of
improvements made and to ensure that the home does not perform worse than it did prior to the
proposed alteration in accordance with Section R503.1. In addition to the Energy Rating Index, a
comprehensive report of the assessment shall be submitted with the building permit application and
include the same criteria as in Tier 1. A post construction assessment shall be submitted prior to
Final Building Inspection to demonstrate compliance. A post-construction Air Leakage Test shall
be performed on the existing building and addition prior to Final Building Inspection demonstrating
a 15% reduction in air leakage.

Exception: Alterations defined below shall not be required to comply with the required assessments
of this section provided that the energy use of the building is not increased.

1. The removal and replacement or the covering of existing materials, elements, equipment or
fixtures using new materials, elements, equipment or fixtures that serve the same purpose.
2. The addition or elimination of any door or window, the reconfiguration or extension of any
system, or the installation of any additional equipment, and shall apply where the work area
is less than 500 sf floor area.
3. Alterations exposing or demolishing more than 75% of the building’s thermal envelope area
shall comply with the energy requirements of Section R407

Renewable Energy Mitigation Program (REMP) Calculators:

REMP (XLS)- Version 2025- Coming April 2025         https://pitkincounty.com/192/Building

 

Effective 12-15-2023

  • County-wide cap on home size; 9250 square feet.
  • Some special areas have a smaller cap at 8250 or 5750 sf.

https://pitkincounty.com/1566/Pitkin-County-Code-Updates

Effective 3-13-2024

  • 2021 IECC
  • Title 11.32 adopts an exterior energy budget of 200 Million Btu’s, 6000 sf snowmelt cap
  • Title 11.34 adopts electric ready provisions; homes must be EV ready and must use electric for heating, cooling and water heating, or provide the electrical infrastructure to convert to electric in the future.

https://pitkincounty.com/DocumentCenter/View/32664/2024-Energy-Code

 

 

Confluence Architecture & Sustainability can help with REMP calculations and provide all the documentation, modeling, testing and certification required to navigate the code.

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…

 

Town of New Castle Energy Code

Posted on by

The Town of New Castle has a unique approach. They do not require a HERS Rating, but they do require a rater-like Building Science technician to inspect construction and fill out their checklist…

2021 Energy Code Building Inspector Checklist

2023 Colorado Model Electrical and Solar Ready Codes

https://www.newcastlecolorado.org/media/3591

 

We do that…

Please give us a call and we can help navigate the process in the most cost-effective way. And optimize your construction for performance.

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

 

Town of Mountain Village Energy Code

Posted on by

As of May 16th 2024…

2021 International Energy Conservation Code

Special provisions for exterior energy use.

Permit fee discounts available for nonexistent or offset exterior energy uses.

Link to Town website and adoption language…

CFA TOMV yes snowmelt no snowmelt
< 3600 Tier I prescriptive prescriptive
3601-7000 Tier II 2021 HERS 60 2021 HERS 60
7001-13000 Tier III 2021 HERS 55 2021 HERS 60
13001+ Tier IV 2021 HERS 50 2021 HERS 60

 

Mechanical rooms and unconditioned space in new construction in the Town of Mountain Village

As a policy we are allowing for mechanical rooms, and unconditioned garages to be exempted from habitable HERS calculations with the following criteria;

  • No heating of any type will be permitted in these locations
  • Exterior envelope insulation requirements shall be met for ALL walls, ceilings and floors (per the HERS design), with a designed thermal break at floors, including concrete (Check with your engineer as this may cause problems with structural slabs).
  • Doors to these rooms shall be fully gasketed
  • At least one, or a minimum of 25% of the walls shall be directly adjacent to the exterior of the structure.

As you are aware, our CDC and the 2018 IECC do not specifically provide for the installation of PV systems to offset HERS ratings in a residential application. The allowance above will hopefully provide for an easier time of meeting the HERS requirements of the Town, and meets prescriptive requirements. In the future, if one of your raters can provide additional information to review that will support the PV to HERS tradeoff, we are available to review.

Thank you and please contact me with any questions

 

Lars Forsythe

Building Inspector

Building Department

Town of Mountain Village

455 Mountain Village Blvd, Suite A

Mountain Village, CO 81435

O :: 970.369.8246

C :: 970.729.3439

 

Performance HERS changes
Currently the Mountain Village Building Regulations has adopted the 2018 energy code. Per (section 17.7.12.7.i.D) renewable energy sources can be used to lower the HERS score if the Smart Build Program is utilized. Buildings designed with a HERS rating below 50 is the starting threshold to allow the renewable offset. It has come to my attention that RESNET/ICC 301 allows for renewable energy sources to be used to lower the HERS score. In keeping with our commitment to support renewable energy the Mountain Village Building Department has reviewed this document and will allow renewable energy to aid in lowering the HERS score. Effective immediately the Mountain Village Building Department will allow all new residential projects to utilize renewable energy sources to lower the HERS score providing:
(1) All 2018 IECC Residential Mandatory requirements in chapter 4 are utilized.
(2) Depending on the type of construction the minimum requirements of 2018 IECC Tables 402.1.2, 402.1.4 and 402.2.6 are followed prior to the addition of the renewable energy source to assist in the HERS score.
(3) Building Regulations section (17.7.12.D. V.I. A), the onsite renewable energy system will be required to be maintained and operational for the lifetime of the property, through a written agreement with the property owner and a covenant on the property.
Inspection Changes as follows:
The Mountain Village Building Department will require the Performance Rater to perform all the insulation inspections. The Performance Rater will be required to sign off on the pre-drywall inspection prior to drywall being installed as well as any partial inspections. An acceptance email must be sent to the building department for all inspections as well as the final acceptance certificate prior to CO being issued. The Building Department will provide a red line stamp on the reviewed plans stating (3rd party insulation inspection required) to help the contractor be aware of this requirement. The following emails may be utilized for the acceptance reports: larsforsythe@mtnvillage.org and dharrington@mtnvillage.org.
Sincerely Drew Harrington
Chief Building Official
970- 708-7537
970- 369-8251

 

Link to Colorado Energy Conservation Code Hub for; Aspen, Basalt, Carbondale, Eagle County, Pitkin County, Town of Snowmass Village and the Town of Mountain Village

Garfield County adopts the 2018 IECC

Posted on by

Effective June 16, 2023

Garfield County has adopted the 2018 International Energy Conservation Code (IECC).

The 2018 version of the IECC features minor changes in insulation values and requires a blower door test to be performed on all new homes to check air-sealing.

Occupant ventilation enforced.

Duct leakage testing enforced if any part of the duct system leaves the thermal envelope.

GarCo will be using the 2021 IECC for multi-family projects; including the provision that lets units under 1500 square feet test for infiltration under the easier surface area metric.

We do that…

Please give us a call and we can help navigate the process in the most cost-effective way. And optimize your construction for performance.

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

City of Glenwood Springs Energy Conservation Code

Posted on by

On June 6, 2022, the City will require building permits to use the 2021 editions of the International Building Code, International Residential Code, International Mechanical Code, International Existing Building Code and International Energy Conservation Code.

 

We do that…

Please give us a call and we can help navigate the process in the most cost-effective way. And optimize your construction for performance.

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

Aspen’s 2021 Energy Code Adoption

Posted on by

Aspen’s adoption of the 2021 I-codes is heavily modified. This article looks only at the energy conservation parts of the adoption. And this is just a summary of the most perennate changes that may influence design.

Link here to the actual adoption documents… 

Four compliance paths:

  1. Prescriptive/Building UA/R-value alternative +23% including all additional mandatory requirements
  2. Performance +5%
  3. ERI +5% (2021 ERI 50.35)
  4. Existing building, Chapter 5

Notable modifications to mandatory residential energy requirements:

  • Prescriptive envelope requirements: R60 roof, R40 walls, R20 basement walls, windows max U-factor of .26 (inert gas with uncapped breather tube units don’t count)
  • Max 30% glazing to wall area (garage and sunroom glazing counts)
  • 1.5 ACH50 air leakage
  • ERV/HRV and flow testing required
  • Duct leakage testing was stricken for the Prescriptive path
  • Special provisions to avoid Thermal bridging
  • Commissioning
  • Sign Up for Building IQ benchmarking program (data gathering)
  • Sensible electric ready provisions
  • New triggers for energy efficiency requirements for alterations

Commercial Energy Changes:

  • Prescriptive, 2019 ASHRAE 90.1 or Performance
  • Envelope infiltration testing; Dwelling and sleeping units .30 CFM50 per square foot of envelope, everything else .40 CFM75 per square foot of envelope.
  • ventilation flow testing
  • Enhanced envelope, especially walls
  • EV requirements
  • Electric ready provisions
  • New triggers for energy efficiency requirements for alterations

Expanded REMP:

  • Heat tape, gas fireplaces, outdoor heaters will now need to be offset
  • Gas fireplaces will be required to be sealed combustion
  • 200,000,000 BTU/year cap for all exterior energy
    • Snowmelt 2414 ft2 OR,
    • Pool 603 ft2 OR,
    • Spa 466 ft2 OR,
    • Heat tape 3125 linear feet of typical heat tape

Incentivize All-Electric New Construction:

  • Expedited Permit Review
  • AC units must be heat pumps

A practical example:

What if a project needs to break with the Prescriptive path? For instance, how can a house go about complying with more than 30% glazing? The project would be forced to try and comply by using either the Performance Path or the ERI (Energy Rating Index) Path.

Minimum Performance goal would be…   2021 Building UA +23% & 72% of Energy costs

Minimum ERI goal would be…                   2021 Building UA +15 % & ERI 50.35 – PV

Both of these goals would have to be achieved without help from PV solar.

 

We do that…

Please give us a call and we can help navigate the process in the most cost-effective way. And optimize your construction for performance.

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

Designing for Net Zero

Posted on by

or just a great HERS / ERI score.

 

It’s not easy to show energy code compliance in climate zones 6 and 7. Especially if you’re working in a jurisdiction that has adopted above-code requirements. Designers here’s an exercise to help get your design on its way to IECC compliance and beyond. On your next project, before starting your typical design process, rough out a schematic design, but forget all clients wishes, ARC guidelines, height limits, etc. and design for energy conservation by substituting the following parameters…

Envelope

  1. Make the thermal envelope a simple, regular volume.
  2. Share assemblies with other structures, when possible, but make that party assembly very airtight.
  3. Follow the prescriptive code for air barriers and insulation levels.
  4. Maximum 20% glazing; 20-30% glazing; plan for really, really good windows, over 30% plan for great triple-pane windows.
  5. Put as much of the insulation on the outside of the assembly as you can, or frame with Efficient Framing techniques or use alternate techniques that reduce thermal bridging like; ICFs, SIPs, Larson trusses, adobe, strawbale, etc.
  6. Make the roof within 20° of optimal pitch (10:12 to 14:12) and orientation (160°-200° south) for solar, free from obstructions and penetrations.
  7. Use passive solar heating techniques when possible; insolation managed by proper overhangs and low-e coatings on glazing.

Equipment

  1. Plan for no gas or propane, all electric house.
  2. Use no snowmelt.
  3. Locate the mechanical room, in the core of the house, minimize distribution runs. Give plenty of room to equipment for service. Easy access; no hatches, ladders or crawling.
  4. Locate the outdoor side of the heat pump equipment. Protected from snow and ice.
  5. Don’t use site-built forced-air ductwork if you can avoid it. Radiant or ductless preferred. If not, don’t combine ductwork with garages, ventilated attics or ventilated crawl spaces. Insulate it and seal it very well.
  6. Plan for a stand-alone occupant ventilation system, with occupant controls and easy access for filter cleaning; not in a crawlspace or attic. Ducting this is okay.
  7. Heating; use GSHP (ground source heat pump) if you can. If not, use ASHP (air source heat pump) and passive heating techniques.
  8. Cooling; skip it altogether if you can. If not, use ASHP, evaporative and passive cooling techniques.
  9. Hot water; use thermal solar per-heat if you can. If not, use HPWH (heat pump water heater). Ducting this is okay.

Electric

  1. Use no heat tape.
  2. Use ENERGY STAR appliances. Keep refrigeration loads as low as possible. Induction range and convection oven.
  3. Plan for low flow plumbing fixtures and fully insulated lines.
  4. Plan for DWHR (drain water heat recovery)
  5. If hot water runs are still long enough to require recirculation, use a smart pump with occupant sensors in the bathrooms and a temperature sensor to control the pump runtimes.
  6. Maximize the PV array size.

Designers: Now you have a schematic design optimized for potential energy conservation. As you move on to your typical design process, keep this design in the background. Know that the more your design develops away from the energy conservation architype, the harder it may be to reach specific performance goals.

Note to Structural Engineers: Your challenge is to help the Architects keep as much steel and wood out of the thermal envelope as possible. Support several inches of Continuous Insulation, even behind stone veneer. Keep the foundation completely covered in insulation, even at patios, doors and behind stone veneer.

Note to Mechanical Engineers: Your challenge is to help the Architects reduce all equipment loads, reduce runs and maximize efficiency. Investigate new technology and equipment and learn how to work with it. And help us all reduce a house’s dependence on gas.

Successful transition to the 2021 IECC

Posted on by

What do we need in place to ensure a successful transition to the 2021 IECC?

Designer and plans examiner education

Architects, mechanical and structural engineers need to be taught high-performance construction techniques. An IECC compliance sheet needs to be created and submitted with Construction Documents. This will help front-load the submittal documents with a more developed mechanical system, air sealing details and specifications. Plans examiners need to learn how to recognize energy conservation issues from drawings a flag them for correction before permit issuance. Once something like a weak party wall assembly is permitted, we’re on the defense for the rest of the game.

General and subcontractor education

Contractors need to know what passing work looks like, preferably before they fail an inspection. The half-dozen raters in the valley cannot be the sole education force for thousands of contractors in the valley. GCs need to know how to interact with a rater; what to include them on, what do they need to see, when to call, etc. Subcontractors need supplemental training on ERV installations, air sealing, Radon barrier installation, etc. New technicians need to be trained on heat pump equipment. I don’t believe there are nearly enough qualified people to install all of the heat pump systems we need to install in the near future. And if it is not done perfectly, the equipment won’t live up to its potential.

Homeowner education

Homeowners need to left with a document that explains how to work the house. Most homeowners seem to be clueless about how to operate an ERV for example. If a homeowner never adjusts the ERV flow or disables it completely, or never changes the filter- we may have done more harm than good in the end. Is the filter replacement schedule being posted? Outdoor reset sensors are now required- are the reset temperature curves being programed before the occupants move in?

Product availability

Builders tend to use the products that the local suppliers carry. We need to start building with products that are not typically stocked in the valley to my knowledge. Specifically I am thinking of items like; airtight electrical boxes, drywall clips, HPWHs (heat pump water heaters), small disposable spray foam kits, liquid flashing, high-performance ERVs and ventilation controllers, vapor-retarding latex primer, etc. Somehow, we need to lobby all of the hardware stores and lumber yards to consistently stock these essential products before significant demand is here.

Enhanced inspection schedule

Rater inspections need to added to inspection checklists, far too many projects go uninspected simple because Raters are not notified of the construction schedule. Ratings only technically require two field inspections, but the reality is that two is not enough. Additional inspections should be required.

  1. Pre-test ducted systems at rough-in, prior to insulation, using 2021 IECC standard, even if all ductwork and equipment is in “conditioned” space.
  2. Blower Door & IR Camera at rough-in, post spray foam in roof and walls, but prior to installation of blown-in or batt insulation. If the home has a vented attic, do visual walk-thru with insulator to identify additional air sealing required, then use Blower Door: 1) As soon as drywall ceilings are hung and fire taped, but prior to hanging drywall on walls. Or 2) As soon as all the drywall is hung, finished, and painted; but before any cabinets or trims are installed.
  3. Insulation Inspection when all insulation is complete

Rater-Building Department coordination and cooperation

Raters and Building Inspectors should have a clear understanding of who is checking for what. In the course of rating a house, we check and test a multitude of things; insulation installation quality, infiltration rate, ventilation rate and watt draw, duct leakage rate, pipe insulation, etc. Typically, JHAs ask me only for a certificate and a blower door test report. Getting an infiltration report without a ventilation report, really doesn’t give you the whole story. So far, ventilation is often being done fairly poorly in the field. There is massive confusion between occupant ventilation, crawlspace ventilation, spot ventilation and make-up air supply. I’m afraid we may see an epidemic of mold erupt in our valley in the near future. And lung cancer caused by Radon.

If the JHA does not ask me for the reports, then I assume they are doing those tests and inspections themselves, or they have a departmental policy not to enforce those parts of the IECC.

Final inspection, confirmed rating certificate and CO

Raters are often unmercifully pressured to cough up a certificate immediately at final. Raters need to have a complete, finished house to do our final inspection and test out; PV on the roof, ERV commissioned, every last piece of pipe insulation installed, door handles on and trades out of our way for testing. After our inspection, it takes a day to update the model and submit all of my paperwork. The it takes a day or two for the Rater to get the final certificate from their provider and transmit it to the General Contractor. GCs need to build this time into their schedule, it is not an instantaneous process.