[{"_1":2,"_88":-5,"_89":-5},"loaderData",{"_3":4,"_26":27},"root",{"_5":6,"_17":10,"_18":19,"_20":21,"_22":10,"_23":-5,"_24":-5,"_25":10},"user",{"_7":8,"_9":10,"_11":10,"_12":-5,"_13":-5,"_14":15,"_16":-5},"roles",[],"isAuthenticated",false,"isPremium","planName","subscriptionStatus","featureFlags",{},"insightsBudget","isDevelopmentHost","userPreferences",{},"recaptchaSiteKey","6LcvOJcUAAAAAHsB-gPGfGktcRlKpH7OTIU_dMTD","isImpersonating","impersonation","affiliateStatus","isFreedomPortal","routes/v2/article/layout",{"_28":29,"_30":31},"notFound",true,"relatedArticles",[32,76],{"_33":34,"_35":36,"_37":38,"_39":40,"_41":42,"_43":44,"_45":46,"_47":48,"_49":50,"_51":52,"_53":54,"_55":56,"_57":58,"_59":60,"_61":62,"_63":64,"_65":66,"_67":68,"_69":70,"_71":72,"_73":74,"_75":74},"mediaId",6119413,"mediaKeyId","2712219-f10087817f763ae81eeec72aca9718ee","parentId",2712219,"title","Board adopts new large and extra‑large home metrics and thresholds; adds Appendix RC pathway and approves two residential code edits","audioSeconds",4872,"startMs",2348000,"endMs",7220000,"viewUrl","/Search/View?dp=1&key=2712219-f10087817f763ae81eeec72aca9718ee&start=2348&end=7220","thumbnailUrl","https://assets.pipeline.soar.com/2712219-f10087817f763ae81eeec72aca9718ee/thumbnail_2348000.jpg","articleUrl","/articles/6119413/Colorado/Board-adopts-new-large-and-extralarge-home-metrics-and-thresholds-adds-Appendix-RC-pathway-and-approves-two-residential-code-edits","mediaUrl","https://secure.pipeline.soar.com/6119413-b88b7e57b4c67e03d7322f0366371744/orig.mp4?Expires=1770845597&Signature=THOzfWT6hY14wSjjUOpTL40Ip2lCD5-meYc3y61kVVNedEuH5C6OsFwM2MFX4S-7tRAurMSzagOD-FpW1d-7kpoK5Y9v8ljqIDDce3gn9JYMU-8bFvLs8WzcaioEL7QRwo4kTRJwvBlJ39tvtMtzgHA-essEVK~XWRJDv7mnonvAW6Mj0jB8hxsUByyN1r56jbqQ1kbI0Re00eRSj2Lj5FRWjgXp7vqV1rScq7SC9i63EM456bkwd4FYzyJPKhPyeZe4Qsae66F9iUnnwpL8OfFHAuicQsbQH7cIyW3nOWR9Hwi17jraxAlpfobMUCzDU4UdD2HAkt-Rs93nmui72w__&Key-Pair-Id=KUT5TJCACFTXG","author","Colorado Energy Office","date","2025-03-06T00:00:00Z","article","After prolonged discussion and multiple straw polls, the Energy Office’s Low Energy and Carbon Code board on Thursday changed how the residential code will define “large” and “extra‑large” homes and approved two residential amendments: one easing slab‑edge insulation requirements where an existing slab prevents practical compliance, and one clarifying required air sealing at interior wall top plates that abut unconditioned spaces.

Definition and metric
The board voted to move away from the 2024 IECC’s living‑space‑above‑grade‑plane metric and instead adopt “conditioned floor area” as the metric used to determine whether a home triggers additional large‑home requirements. To account for the lower energy intensity of below‑grade conditioned spaces, the board adopted an equation that measures a home’s size as: all conditioned floor area above grade plus 50% of conditioned floor area below grade. That equation won a majority on a straw poll after members discussed ease of enforcement and fairness for homes with large basements.

Size thresholds
Using the new metric the board set the numeric thresholds as follows:
- Large homes: 5,000 square feet (conditioned floor area above grade + 50% of conditioned area below grade yields the reported figure) — adopted by majority vote.
- Extra‑large homes: 7,500 square feet (using same metric) — adopted by majority vote after a runoff between competing values.

The board also decided that extra‑large homes would be subject to the more stringent prescriptive options in Appendix RC; rather than embedding the entire appendix in the base code, members voted to reference Appendix RC (option to “go to appendix”) so that jurisdictions and designers can read and apply the appendix directly. That approach was chosen to reduce complexity in the base code while preserving the Appendix RC compliance pathway.

Residential code edits passed
Two additional residential proposals were voted and passed during the session:
- R402.2.13 (slab insulation): The board approved an exception allowing builders to omit a slab‑edge insulation retrofit for existing slabs where the owner or site conditions prevent practical or safe installation, provided the rest of the prescriptive envelope requirements are met. The motion passed by vote (13 yes, 3 no, 2 abstain) and staff will add clarifying language and trade‑off options in the draft.
- R402 top‑plate/party‑wall air sealing clarification: The board approved clarified language requiring sealing of interior walls that abut unconditioned spaces or otherwise create top‑plate penetrations to unconditioned attics or voids. The edit was intended to remove ambiguity in multifamily and attached housing when a unit separation or attic interface would otherwise be missed by a narrow interpretation. The motion passed (15 yes, 1 no, 1 abstain) and will be incorporated into the next draft.

Votes at a glance
- Metric to measure home size: board chose conditioned floor area (with below‑grade weighted at 50%) over living‑space above‑grade — passed via straw poll.
- Large‑home threshold: 5,000 sq ft (using the adopted equation) — passed (majority).
- Extra‑large threshold: 7,500 sq ft (using the adopted equation) — passed after runoff (majority).
- Extra‑large compliance approach: reference Appendix RC rather than embedding all language in the body — passed (19 yes).
- R402.2.13 slab‑insulation exception: passed (13 yes, 3 no, 2 abstain).
- Interior wall top‑plate sealing clarification: passed (15 yes, 1 no, 1 abstain).

Why it matters
These choices change which new homes will be subject to more stringent “large‑home” efficiency requirements. Moving to conditioned floor area and explicitly including a share of below‑grade area was intended to prevent circumvention (for example, building large below‑grade spaces but avoiding above‑grade thresholds) while recognizing lower heating and cooling loads for true below‑grade spaces. Reference to Appendix RC for extra‑large homes creates a clear, higher‑stringency compliance pathway for the very largest dwellings without over‑complicating the base code.

Next steps and open issues
Staff will incorporate the metric language and numeric thresholds into the next draft for public review. Board members and industry representatives flagged the need for additional clarifying text about what qualifies as conditioned/occupiable space and how finished/unfinished basements will be measured; staff and members agreed to refine definitions and to capture those clarifications in draft 2. The air‑barrier/inspection sequencing commercial item remains unresolved and will return after offline work by proposers and staff.

Speakers
Kim (board chair), Carolyn (board member, large‑home proposer), Adam (staff/consultant), Andrew (builder representative), Tim (board member), Elizabeth (board member), Ron (board member), Jess, Kristen, Dan (proposer), Tom (participant).

Clarifying details
- Adopted metric: conditioned floor area above grade + 50% of conditioned floor area below grade.
- Large‑home threshold: 5,000 sq ft (per adopted metric).
- Extra‑large threshold: 7,500 sq ft (per adopted metric); extra‑large homes to follow Appendix RC requirements by reference.
- R402.2.13 slab exemption: available when existing slab makes edge insulation impractical; trade‑offs expected.
- Interior wall sealing: applies to interior walls that abut unconditioned spaces (attics, voids) and to separations between units where applicable.

Authorities referenced
- 2024 International Energy Conservation Code (IECC)
- Appendix RC (referenced for extra‑large homes)
- Appendix RG (previously discussed as strengthening option for large homes)

Proper names
[{\"name\":\"Energy Office\",\"type\":\"agency\"},{\"name\":\"IECC 2024\",\"type\":\"statute\"},{\"name\":\"Appendix RC\",\"type\":\"other\"},{\"name\":\"Appendix RG\",\"type\":\"other\"}]

Searchable tags
[\"home-size\",\"conditioned-floor-area\",\"Appendix-RC\",\"R402\",\"large-home\",\"extra-large-home\",\"slab-insulation\",\"air-sealing\"]","mediaType","Video","parentTitle","Energy Code Board Low Energy and Carbon Code - 2025-03-06 - Meeting #25","oneSentenceSummary","The Energy Office board adopted conditioned floor area (with a 50% weight for below‑grade conditioned area) as the metric to determine large homes, set a 5,000‑square‑foot large‑home threshold and a 7,500‑square‑foot extra‑large threshold, and decided extra‑large homes should follow Appendix RC requirements by reference.","taxTitle","Energy Office, State Agencies, Organizations, Executive, Colorado","taxId",27601,"location","Colorado","headline","","shortSummary",{"_33":77,"_35":36,"_37":38,"_39":78,"_41":79,"_43":80,"_45":81,"_47":82,"_49":83,"_51":84,"_53":85,"_55":56,"_57":58,"_59":86,"_61":62,"_63":64,"_65":87,"_67":68,"_69":70,"_71":72,"_73":74,"_75":74},6119418,"Energy Office board approves EV-ready exception and electric-ready circuit language; tables air-barrier inspection sequencing",1539,359000,1898000,"/Search/View?dp=1&key=2712219-f10087817f763ae81eeec72aca9718ee&start=359&end=1898","https://assets.pipeline.soar.com/2712219-f10087817f763ae81eeec72aca9718ee/thumbnail_359000.jpg","/articles/6119418/Colorado/Energy-Office-board-approves-EV-ready-exception-and-electric-ready-circuit-language-tables-air-barrier-inspection-sequencing","https://secure.pipeline.soar.com/6119418-cd9855ddc8e4d48713bdd34f436f13e9/orig.mp4?Expires=1770845597&Signature=W2Ngxyhy8oXPox~nJ8Bw9zsmemo2J1XIdpi4lqCkeliu2-uePJFbOsrGxL9KbQ5AsDoxk9dCdIV-wzLK~DB3UwbM5XqwY7B4a3mRSFoAp5B64hmIXnwYO9Vtt7hiNFL6Ehgz3O86dTCUiqEjfPZ~sR8gzPFz1BLx5xXPcETDgy9VQJYI6-Eld6UmKc6UWO-NebFPYQFOx59mNaoiMPCtWtejqzzH2B0rlBKdK~wZPrpHNnsG6g-ijW4omo1bwsKVA3rLZ~0HqiTIs9fAPoh15ikjIpuGibilC-CKcFC9jiGKYQyI2WoKjD97LWxy1lx38CDT4HFJ7tlRmbRn8Qyr4A__&Key-Pair-Id=KUT5TJCACFTXG","The Energy Office’s Low Energy and Carbon Code board on Thursday approved changes to commercial electric‑readiness rules and a new exception to the EV-ready requirements for large parking lots, and tabled a proposed change about the timing of third‑party air‑barrier verification so staff and proposers can combine competing wording.

Board members voted to add an exception to the commercial EV-ready requirements that allows design teams to terminate conduit runs at a future transformer or panel location rather than running all conduits back to the existing service. The board’s rationale: the change gives designers flexibility on very large parking fields where meeting conduit‑routing and service‑sizing criteria can be impractical. The straw poll on the proposed edits to C4.10.5 returned unanimous support in the meeting’s roll call (18 yes, 0 no, 0 abstain) and the proposal passed.

The board also amended the electric‑ready language covering future electric cooking and clothes‑drying equipment. After discussion about whether the code should require designers to calculate “heating load” for appliances, members agreed to replace that term with “equipment load,” add a cross‑reference to the National Electrical Code (NEC) for circuit capacity, and to require a dedicated circuit sized appropriately for the replacement application. Members voted in favor of the combined edits (straw poll: 18 yes, 0 no, 0 abstain), and the change will be applied in two mirrored sections of the commercial code (the C4.10 subsections discussed in the meeting).

On the topic of third‑party air‑barrier verification and sequencing for larger commercial buildings, two board members (Tim and Brad) had submitted alternative wording about when a third‑party air‑leakage inspector must confirm scope and sequencing — at plan review versus before final framing/insulation inspections. Board members discussed enforceability and the coordination challenges for large projects; several members recommended combining elements of both proposals. The board did not complete that decision and agreed to have Tim and Brad work offline with staff to produce unified language for a future meeting. The item was explicitly tabled pending that rewrite.

The meeting also included one administrative correction: the board accepted an edit that clarifies which Group R occupancy types the commercial code references. That alignment was treated as an administrative fix rather than a contested policy change and the board agreed to update the citations in the commercial section accordingly.

What happened next
The board asked staff and the proposers to submit combined language on the air‑barrier inspection timing for review at a future session. Staff said the approved administrative edits and the passed electric‑ready and EV exceptions will be incorporated into the next publicly posted draft of the code.

Why it matters
The EV exception and electric‑ready clarifications are aimed at reducing upfront design and construction cost and permitting complexity on large commercial projects while preserving the code’s intent to make sites easier to electrify in the future. Delaying a decision on inspection sequencing preserves board time and lets the authors reconcile competing enforcement approaches before formal adoption.

Votes at a glance
- EV-ready exception (C4.10.5 exception as proposed): straw poll 18 yes, 0 no, 0 abstain → passed.
- Electric-ready dedicated circuit language (C4.10 edits in two sections): straw poll 18 yes, 0 no, 0 abstain → passed.
- Air-barrier inspection sequencing (C402.60.20.3 / related): tabled for offline language consolidation → no formal vote.
- Administrative fix to Group R occupancy references in C4.10: accepted as administrative correction → no formal recorded roll call.

Speakers
Board chair Kim (chair), Tim (board member), Brad (board member), Carolyn (board member), Kevin (board member), Elizabeth (board member), Ron (board member), Adam (staff/consultant), Naomi (staff member).

Clarifying details
- EV exception rationale: applied to very large parking fields (examples cited: projects with hundreds to 1,000+ parking spaces where conduit runs to existing service would be costly).
- Electric‑ready edit: replaces “heating load” language for appliance readiness with “equipment load” and references NEC circuit sizing; applies to two subsections of C4.10.
- Air‑barrier sequencing: proposers aim to require evidence of a third‑party testing scope and confirmation prior to issuance of permit or prior to completion of final framing inspections; consolidated language to be produced offline.

Authorities referenced
- 2024 International Energy Conservation Code (IECC), commercial sections (referenced by speakers in context)
- National Electrical Code (NEC) (referenced by board for circuit sizing guidance)

Searchable tags
[\"EV-ready\",\"electric-ready\",\"air-barrier\",\"third-party testing\",\"commercial building\",\"C4.10\",\"C402\",\"NEC\",\"Energy Office\"]","The Energy Office low-energy code board approved a commercial EV-ready exception and updated electric-ready circuit language for future electric cooking and clothes-drying equipment, and agreed to develop combined air-barrier inspection sequencing language offline.","actionData","errors"]

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Board adopts new large and extra‑large home metrics and thresholds; adds Appendix RC pathway and approves two residential code edits

Energy Office board approves EV-ready exception and electric-ready circuit language; tables air-barrier inspection sequencing