Confluence Architecture was instrumental in turning an old 1970 energy hog home into a an efficient, low energy use residence. The project qualified for $12,000 in grants from CORE and $7,092 in rebates from Holy Cross Energy. The home is fully electric and uses air-source heat pumps for heating and cooling. It is projected to be net-zero. Confluence was responsible for planning, architecture and energy modeling on this home.
Before
After
Confluence Architecture has worked with the Blue Lake Preschool non-profit to find a permanent new home for their Carbondale location. Can’t wait to see this light- filled, efficient space up and running.
Town of Snowmass Village Community Development website here…
2015 International Energy Conservation Code (IECC) and REOP adoption…
Ordinance No. 2 2011 adoption…
| Town of Snowmass Village | CFA | Maximum |
| Tier I | 1000-3000 | HERS 75 |
| Tier II | 3001-5000 | HERS 70 |
| Tier III | 5001-10000 | HERS 65 |
| Tier IV | 10000+ | HERS 60 |
Link to Colorado Energy Conservation Code Hub for; Aspen, Basalt, Carbondale, Eagle County, Pitkin County, Town of Telluride and the Town of Mountain Village
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 |
As a policy we are allowing for mechanical rooms, and unconditioned garages to be exempted from habitable HERS calculations with the following criteria;
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
We are excited to showcase a new home we designed in Aspen Glen. It is a 2500 sf, 3 bedroom home for a young family. The form of the home has 2 axis to respond to a challenging parallelogram lot. The home includes indoor/outdoor features including an in and out bar window between the kitchen and rear patio. The master bedroom has a wrap around deck with views oriented towards t Mount Sopris.
Confluence Architecture along with local non-profit Blue Lake Preschool is honored to announce that after searching for 5 years they were able to find a permanent location. Last September, Blue Lake Preschool acquired the property at 55 N 7th st, which happens to be the former residence of Mary Ferguson, a Carbondale icon. She was born at Spring Gulch in 1906, taught in one room schoolhouses, was a town council member, a volunteer and historian. We find this connection to be a valuable continuation of Mary’s love of teaching.
Construction is now underway on the addition and remodel to to transform this 1950’s ranch home into an energy efficient healthy and cozy preschool. Some of the energy efficiency attributes include addressing air circulation and filtration by utilizing a HRV system with Merv 13 filter, and upgrading the insulation. We seek to replace all the flooring with environmentally friendly natural linoleum and will use zero or low VOC paints.
Confluence Architecture has thrown its support behind this worthy project by contributing our professional services of planning, property analysis, and Architectural services. Blue Lake Preschool is seeking funding to assist with construction. This permanent home will allow Little Blue to increase the number of infant care spaces in Carbondale, a critically underserved demographic. We encourage all to donate to this worthy cause. Donations can be made at Blue Lake’s website https://bluelakepreschool.org/donate.
Link to adoption language, Article 9…
effective February 18, 2020
c) Residential Energy.
(1) Amend Section R401.2 “Compliance” to read:
All new buildings and any building having an addition of 1000 square feet or greater shall comply with Section R406. All other buildings shall comply with one of the following:
The remainder of the section remains unchanged.
R402.2.14 Exterior Walls. Recess step lights are not permitted in exterior building walls except where the required R-value is met for the wall assembly.
(3) Add a sentence to Section R402.4.5 to read:
Recessed can lights are allowed in ceiling-roof assemblies only if the required R-value of insulation can be met between the top of the fixture and the roof decking material.
(4) Amend Table R402.4.1.1 by adding to the Insulation Installation Criteria for the Walls Component:
Wood or Engineered Headers-R-10 wherever possible.
Steel Header – R-10 with insulation provided on both the exterior and/or the interior sides of the steel if possible, to maintain a continuous thermal barrier.
(5) Amend Section R403.5.3 to read:
R403.5.3 Hot water pipe insulation (Mandatory). Insulation for hot water piping with a thermal resistance, R-value, of not less than R-3 shall be applied to the following:
Items 1 through 7 remain unchanged.
8. Hot water line piping shall not be placed in an exterior wall to the extent practical. When not practical as determined by the Building Official, hot water piping may be placed in an exterior wall provided the required insulation R-value of the wall is provided in between the piping and the exterior of the wall.
9. An insulating blanket shall be provided that covers entire water tank fastened with appropriate tape.
(6) Add a last sentence to Section R403.7 to read:
Systems shall be designed by a certified Mechanical Engineer for single family residential structures greater than 2,000 sq. ft. of gross floor area including the basement area.
(7) Amend Section R406.1 to add to the following as the last sentence:
ERI refers to the ERI Home Energy Rating System (HERS) score.
(d) Additional Requirements for Residential and Commercial Buildings.
(5) Pools and Spas (Hot Tubs).
(11) Renewable Energy.One hundred percent (100%) of the building’s electricity use must be provided for with renewable energy, either produced on site or purchased through a Green Power Production Program. Creative alternative options will be considered by the Building Department. (Ord. 1502 §1, 2020)
One stop for energy code information on the multiple jurisdictions of the Roaring Fork Valley, Telluride and Mountain Village.
I will try to keep this list current.
Jump to Aspen Colorado’s energy conservation code compliance page…
Jump to City of Glenwood Springs, Colorado’s energy conservation code compliance page…
Jump to Eagle County Colorado’s energy conservation code compliance page…
Jump to Garfield County Colorado’s energy conservation code compliance page…
Jump to Pitkin County’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…
Jump to TOMV energy code compliance page…
Jump to TONC energy code compliance page…
Jump to TOSV’s energy conservation code compliance page…
Jump to Town of Telluride Colorado’s energy conservation code compliance page…
Jump to San Miguel County’s energy code compliance page…
Effective 12-15-2023
https://pitkincounty.com/1566/Pitkin-County-Code-Updates
Effective 3-13-2024
https://pitkincounty.com/DocumentCenter/View/32664/2024-Energy-Code
For permit submittals… Prescriptive, Total UA and the Performance Paths have been deleted. Projects must use the HERS compliance path. Projects must show a HERS of 60 before photovoltaic solar energy is applied, and HERS 30 afterwards.
For remodels and additions exceeding 1000 sf a baseline blower door test must be submitted. This is needed to show that the new construction demonstrates 15% reduction in air leakage. Less than 1000 sf are exempt from infiltration testing requirements.
Option 1: Prescriptive, demonstrate compliance with Articles 401-404 and the Pitkin County Amended Tables 402.1.2 and 402.1.3 in the Pitkin County Amended 2021 IECC. (this includes modified U-factors of .28 for exterior glazing and .40 for skylights, gas fired furnaces shall meet a minimum 95% AFUE. AC equipment will meet a minimum SEER rating of 16, etc.
Option 2: Alternative compliance if approved by the Chief Building Official. This would most likely include a HERS rating of 53 from table R406.5 in the 2021 IECC, or an above-code program certification like; ENERGY STAR or LEED for Homes.
https://pitkincounty.com/DocumentCenter/View/32664/2024-Energy-Code
Building thermal envelope -2021 IECC prescriptive table or pass a 2021 ComCheck thermal envelope compliance report.
Lighting -Pass a 2021 ComCheck Interior and exterior lighting compliance report.
Mechanical -Pass a 2021 ComCheck mechanical compliance report.
Renewable Energy Mitigation Program (REMP) payment option is voluntary. Applicants interested in exterior energy use systems can alternatively choose to produce on-site renewable energy (Section 301) with solar photovoltaics and/or solar hot water, ground-source heat pumps or micro-hydro. Download Pitkin County REMP Calculation Sheet
Confluence Architecture & Sustainability can help with REMP calculations and provide all the documentation, modeling, testing and certification required to navigate the code.
Beginning the 1st of July 2020, The Town of Carbondale revised their REBP (Residential Efficient Building Program). Carbondale is currently on the 2009 IRC (International Residential Code), the 2012 IgCC (International Green Construction Code) and the 2015 IECC (International Energy Conservation Code).
Link to REBP guidelines and REBP checklist here…
Carbondale has adopted the 2015 IECC and has a REBP (Residential Efficient Building Program). The chart below is the crux of understanding the energy code compliance.
Note that SF in this case refers to a special definition in the REBP glossary. Ignore “floor area” and look to “total square footage”; where it says “for the purposes of this program…”. floor area will mean; inside of walls, include basement, exclude garage, no deduction for unfinished areas, storage or structure.
What are the submittal requirements? Let me try and unpack what this chart means.
Carbondale has made solar PV mandatory in almost all cases. Is this lopsided push for PV is born out of COREs mission to electrify all houses? And why not PV? Because- the point of doing an energy model is to find the most cost-effective path to a set goal. If you declare PV the winner without a fight, you have cheated the science, tipped the scales. PV is pretty great, when would it really matter? When glazing becomes a large portion of the envelope load. When does that happen? Remodels obviously. The math might show that the old windows should really be replaced for reasons of heat loss, service life, comfort, etc. but, the project has already blown it’s wad on a PV system, got all the points they need, window replacement off the table. Another time glazing becomes overwhelmingly important- large areas of glazing facing south or west. I routinely see custom homes in River Valley Ranch with more than 30% glazing factor (30% of the above grade walls are made from glass). In these homes getting the right kind of glazing is huge. Sometimes the SHGC is more dominate than the U-factor! These southern view window walls are the only reason some of these houses require air conditioning. Also, a blind favoritism towards PV will stifle development/implementation of other kinds of renewable energy production, sorry GSHP, thermal solar and Drain Water Heat Recovery. Same argument for CI on the walls. The code does not make CI mandatory, I think, because flexibility is good, and CI can easily be traded off for better performance elsewhere. Ranch style houses typically have more roof area than walls area, why not make CI on the roof mandatory? It would move the needle more. And on the roof, you don’t even have all the technical problems with fenestration openings, siding and stone veneer attachment, etc. CI has many wonderful benefits, and I recommend it for most jobs, but it is rarely the first most cost-effective way to conserve energy. Ok, I’m getting off the soapbox, on with the submittal requirements…
I’m told the “percent better than code” row should be stricken from this chart; it no longer applies.
I’m told the “(option)” under the Tier 1 column means that a less than 2000 square foot house can submit using the prescriptive path as long as 1.5 watts per square foot of PV is provided. I don’t understand why, but they also require a Total UA Compliance calculation to be performed and submitted. No requirement to perform over basic compliance, so it just equal to prescriptive anyway. Or submit a Projected HERS rating of 50 in lieu, PV or not.
So basically what Carbondale is saying is that the prescriptive (402.1), the performance path (405) and ERI (406) are not a compliance option. Every single project will have to submit at least a Total UA Compliance Calculation (402.1.5), and PV design showing 1.5 watts per square foot or a HERS rating.
Currently, the Town is not considering ADUs (Accessory Dwelling Units) as their own unit. No need to include in REBP submittal, HERS rating or blower door infiltration test.
The required points refer to the REBP checklist (an Excel spreadsheet). Points are earned by including features in the house like, efficient framing, water conservation, chemical reduction, etc. Refer to the guidelines to understand how to fill out the checklist. Extra points are awarded for above code HERS (Home Energy Rating Score), infiltration rates and solar. Confluence can perform these tests and produce these compliance reports. Please call us early in the process so we can help you optimize the insulation and comply with the energy code in the most cost-effective way.
Carbondale is on the 2009 IBC (International Building Code), but they have also adopted the 2012 IgCC (International Energy Conservation Code).
Link to Carbondale’s heavily amended adoption of the IgCC here…
Navigating the IgCC is a deep subject, but expect it touch every phase of your project. The code requires above IECC insulation and infiltration mitigation, construction waste tracking and structured plumbing. The code requires third-party inspections and testing for the envelope. Confluence has been the code compliance and envelope consultant for six IgCC projects now. The Town of Snowmass Village has also adopted this code. Please calls us early in the process if you are planning a commercial project in The Town of Carbondale or The Town of Snowmass Village.
Jump to ICC’s overview of the International Green Construction 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…