Building Code Glossary
Energy Cost: Building Code Definition
How the IECC 2009 define energy cost, where the wording differs, and which chapters depend on the term.
On this page
Last updated September 7, 2026 · Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The [ICC code library](https://codes.iccsafe.org/codes) publishes the current model text and the [ICC adoption maps](https://www.iccsafe.org/advocacy/code-adoption-maps/) show which edition a jurisdiction has adopted; those sources control.
Direct answer
Energy cost is a defined term in the International Energy Conservation Code (IECC) 2009, in Definitions. The code's own words are: “The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.” No other I-Code in this corpus defines it, so the IECC 2009 definition is the one to work from. The term is used in 3 chapters of this corpus, most often in Commercial Energy Efficiency (IECC 2009), Residential Energy Efficiency (IECC 2009), Definitions (IECC 2009). These pages transcribe the 2009 model text; verify the definition against the edition and amendments your authority having jurisdiction has adopted. Record the jurisdiction, the adopted edition, the application date and any local amendment that rewrites the definition before you use it on a live project, because a term redefined by amendment changes every requirement that depends on it.
Content and cited inputs reviewed by Scott Barrington, Harth founder and architectural technology specialist · Published 2026-09-07 · Updated 2026-09-07.
What does this term mean?
Energy Cost — IECC 2009, Definitions:
The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.
What must be verified before using this guidance?
Energy Cost is defined once in this corpus, in the Definitions chapter of the International Energy Conservation Code (IECC) 2009:
The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.
Where energy cost is used in the code
The term appears in 3 chapters of the 2009 I-Codes hosted here. The chapters that lean on it hardest are the ones to read next.
| Chapter | Code | Mentions |
|---|---|---|
| Commercial Energy Efficiency | IECC 2009 | 12 |
| Residential Energy Efficiency | IECC 2009 | 5 |
| Definitions | IECC 2009 | 1 |
The term in use
How the code actually writes about energy cost, quoted from the 2009 text hosted here:
Code officials shall be permitted to require time-of-use pricing in energy cost calculations.
The terms energy cost is built out of
The definition above leans on 2 other defined terms. Each carries its own code definition, and a local amendment to any of them changes what energy cost covers:
- Building — IBC 2009: Any structure used or intended for supporting or sheltering any use or occupancy.
- Demand — IRC 2009: The maximum amount of gas input required per unit of time, usually expressed in cubic feet per hour, or Btu/h (1 Btulh = 0.2931 W).
Energy Cost: what to open, and in what order
Every row is a document this term depends on. The ICC code library and the ICC adoption maps cover the middle rows.
| Check | Where | Confirmed |
|---|---|---|
| Read the definition in the adopted IECC | Definitions | |
| Re-check the requirement that uses it | Commercial Energy Efficiency (IECC 2009) | |
| Re-check the requirement that uses it | Residential Energy Efficiency (IECC 2009) | |
| Re-check the requirement that uses it | Definitions (IECC 2009) | |
| Confirm the dependent definition | Building | |
| Confirm the dependent definition | Demand | |
| Local amendment to any of the above | Jurisdiction's amendment list |
A research aid, not a code determination. The authority having jurisdiction decides which edition and which amendments apply.
Where can you explore related guidance?
Sources and method
Definitions quoted from the 2009 International Codes as transcribed in this site's building-codes collection, with the source chapter linked for each quotation. Usage counts are computed over the chapters hosted here, one copy per code. The ICC code library publishes the current model text and the ICC adoption maps show which edition a jurisdiction has adopted; those sources control.
Source links
Frequently asked questions
What is the code definition of energy cost?
The International Energy Conservation Code (IECC) 2009 defines it in Definitions as: “The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.” The 2009 model text is reproduced here; the definition that binds your project is the one in the edition your jurisdiction has adopted, as amended locally.
Which parts of the code depend on energy cost?
In this corpus the term is used across 3 chapters, led by Commercial Energy Efficiency in the IECC 2009. Those are the sections whose scope moves if the definition is amended locally, so read them together with Chapter 2 rather than on their own.
What are building energy codes?
Building is a separate defined term. The IBC 2009 defines it as: “Any structure used or intended for supporting or sheltering any use or occupancy.” That is not the same as energy cost, which the IECC 2009 defines as “The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.” — read both before applying either, and confirm the wording in the edition your jurisdiction has adopted.
What does "energy cost" mean?
In the 2009 I-Codes hosted here it is a defined term rather than a description. The IECC 2009 states, in Definitions: “The total estimated annual cost for purchased energy for the building functions regulated by this code, including applicable demand charges.” It is defined in IECC 2009. Because it is a defined term, whatever the adopted edition says it means is what every section using it means — so check Chapter 2 of that edition and any local amendment before relying on this wording.
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