78 Commercial Energy Plans Examiner Exam Prep

78 Commercial Energy Plans Examiner Study Guide

Exam Overview

Commercial Energy Plans Examiner (78)

• Questions: 70 multiple-choice
• Time Limit: 3.5 hours (210 minutes)
• Format: Open book
• Cost: $320
• Code Books: 2024 IECC (International Energy Conservation Code) — Commercial Provisions
• Passing Score: 70% (49 of 70 questions)

Exam Content Breakdown (2024 outline weights)

1. Administration and General Requirements – 20% (14 questions)
2. Building Thermal Envelope – 30% (21 questions)
3. Mechanical Systems – 25% (18 questions)
4. Service Water Heating Systems and Equipment – 4% (3 questions)
5. Electrical Power and Lighting Systems – 10% (7 questions)
6. Additional Efficiency and Commissioning – 6% (4 questions)
7. Existing Buildings – 5% (4 questions)

1. Administration and General Requirements (20%)

The Plans Examiner's Job Under the IECC

Where the inspector verifies installed work, the plans examiner verifies that the construction documents demonstrate compliance before the permit is issued (C105). Most 78 questions ask either "what must the documents show?" or "given these plan values, do they comply?"

Applicability (C101-C102, C402.1.1)

• C101.4: residential buildings meet IECC–Residential Provisions; commercial buildings meet IECC–Commercial Provisions
• C102.1: where sections specify different requirements, the most restrictive governs (IECC C102.1); between a general and a specific requirement, the specific requirement governs
• C102.1.1: mixed residential/commercial buildings — each portion is separately considered and meets the applicable provisions
• Low-energy building exemption (C402.1.1): plans claiming envelope exemption must demonstrate peak space-conditioning energy below 3.4 Btu/h·ft² (1.0 W/ft²) or that the space is unconditioned — walk-in freezer warehouses and equipment shelters are typical examples

Construction Documents (C105.2)

The documents must show, at minimum:

• The energy compliance path (Item 1)
• Insulation materials and their R-values (Item 2)
• Fenestration U-factors and SHGC values; area-weighted calculations where averaging is used (Items 3-4)
• Air barrier and air-sealing details, including the location of the air barrier (Item 5); thermal bridges per C402.7 (Item 6)
• Mechanical system design criteria; equipment types, sizes and efficiencies; economizer description; equipment and system controls (Items 7-10)
• Fan motor horsepower and controls (Item 11); duct sealing, duct and pipe insulation and location (Item 12)
• Lighting fixture schedule with wattage and control narrative (Item 13); location of daylight zones on floor plans (Item 14)
• On-site renewable energy system routing, ESS location/capacity where applicable (Items 15-18)

If the documents do not demonstrate compliance, the application is incomplete — the examiner requests revisions; approval "to keep the project moving" is the wrong answer on this exam.

Design Criteria (C301-C303)

• Confirm the project's climate zone from Figure C301.1 or Table C301.1, based on the county where the building is located, before checking any tabled value — an examiner who accepts Zone 4 insulation in a Zone 5 county has approved a non-compliant building
• C303: material and insulation identification/installation documentation (manufacturer's R-value, markings, protection of exposed foam)

Compliance Paths (C401.2)

Every commercial review starts by identifying the declared path (C401.2.1):

1. Prescriptive Compliance — Sections C402 through C406, plus Section C408 commissioning
2. Simulated Building Performance (SBP) — Section C407 energy modeling

Or, as a wholly separate application track (C401.2.2): ASHRAE/IES 90.1 compliance in lieu of the IECC chapters.

Paths cannot be mixed within a building (C401.2). Dwelling and sleeping units in Group R-2 buildings without systems serving multiple units may instead comply with residential Section R406 — a legitimate cross-reference to the IECC–Residential Provisions, not a typo.

Performance Compliance Documentation (C401.3, C407)

• C401.3: the permanent thermal envelope certificate documents installed insulation R-values, fenestration U-factors/SHGC, and any envelope air-leakage test results; it is posted on a wall in the space containing the space-conditioning equipment, a utility room, or other approved location
• C407: see Section 6 below for the Total Building Performance submittal contents; C408 commissioning/maintenance information is covered there and in Section 6 (Additional Efficiency and Commissioning)

2. Building Thermal Envelope (30%)

Insulation Requirements (Table C402.1.3, C402.2)

The documents must declare one of three opaque-assembly compliance methods:

1. R-value method (Table C402.1.3) — verify each assembly's cavity and continuous insulation against the table for the climate zone. Cavity insulation cannot substitute for required continuous insulation; layered ci values may be summed, as may layered cavity values
2. U/C/F-factor method (Table C402.1.2) — assembly calculations must support every claimed U-factor; verify the math, not just the summary table
3. Component performance alternative (C402.1.4) — a trade-off equation (Equation 4-1); the examiner checks that the proposed total heat loss does not exceed the budget