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: 2021 IECC (International Energy Conservation Code) — Commercial Provisions
• Passing Score: 70% (49 of 70 questions)

Exam Content Breakdown

1. General/Administration – 14% (10 questions)
2. Building Envelope (Plans) – 24% (17 questions)
3. Mechanical Systems (Plans) – 22% (15 questions)
4. Service Water Heating (Plans) – 10% (7 questions)
5. Electrical/Lighting (Plans) – 18% (13 questions)
6. Compliance Paths and Documentation – 12% (8 questions)

1. General/Administration (14%)

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 (C103). Most 78 questions ask either "what must the documents show?" or "given these plan values, do they comply?"

Construction Documents (C103)

The documents must show, at minimum:

• Insulation materials and their R-values, by assembly and location
• Fenestration U-factors and SHGC values
• Area-weighted U-factor and SHGC calculations where averaging is used
• Mechanical system design criteria; equipment types, sizes and efficiencies
• Economizer description; equipment and system controls
• Duct sealing, and duct and pipe insulation and location
• Lighting fixture schedule with wattage and control narrative
• Air sealing details and the location of the continuous air barrier

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.

Compliance Paths (C401.2)

Every commercial review starts by identifying the declared path:

1. Prescriptive — Sections C402 through C406, plus C408 commissioning
2. Total Building Performance (TBP) — Section C407 energy modeling
3. ASHRAE/IES 90.1 — the whole standard in lieu of the IECC chapters (C401.2.2)

Paths cannot be mixed. Dwelling and sleeping units in Group R-2 buildings without shared systems may instead comply with residential Section R406.

Other Administration Anchors

• C101.4: where requirements conflict, the most restrictive governs
• C101.5: residential portions of mixed buildings follow the residential provisions
• C105: the inspection sequence the approved documents must support
• C401.3: the thermal envelope certificate — contents and posting location are document-review items
• Chapter 3: confirm the project's climate zone from Table C301.1 before checking any tabled value; an examiner who accepts Zone 4 insulation in a Zone 5 county has approved a non-compliant building

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. Greenhouses have their own criteria in C402.1.1.1.

2. Building Envelope Plan Review (24%)

Choosing and Checking the Opaque Method

The documents must declare one of three opaque-assembly 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 C402.1.4) — assembly calculations must support every claimed U-factor; verify the math, not just the summary table
3. Component performance alternative (C402.1.5) — a trade-off equation; the examiner checks that the proposed total heat loss does not exceed the budget

Group R occupancy portions use the Group R columns — a mixed office/apartment building needs both columns applied to the right assemblies.

Fenestration Review (C402.4)

• Verify vertical fenestration ≤ 30% of gross above-grade wall area and skylights ≤ 3% of roof area from the elevations and roof plan
• If the plans show up to 40% / 6%, confirm the daylight-zone plans, daylight responsive controls, and VT ≥ 1.1 × SHGC documentation that C402.4.1.1 and C402.4.1.2 demand (Zones 0–6 only for the 40% allowance)
• Skylight mandate (C402.4.2): enclosed spaces over 2,500 ft² under a roof with ceilings over 15 feet in listed uses (warehouses, retail, gymnasiums, offices…) must show skylights over at least half the floor area as toplit daylight zone — check the reflected ceiling plan
• Check window schedules against Table C402.4 U-factor and SHGC maximums (e.g., fixed fenestration U-0.36 in Zones 4–5; entrance doors U-0.83 in Zones 0–1, U-0.63 in Zones 4–8). NFRC ratings, not center-of-glass values, govern
• Area-weighted averaging is permitted within fenestration categories — the calculation must be on the documents