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newSchoolWorks.com › VoTechWorks › Business & Cross-Cutting › Home & Building Inspection › Certification Exam Preparation: InterNACHI CPI, ASHI ACI, and State Licensing › Lesson 2
BUS-HOME77-11 · Lesson 2 · 10 clock hours · practice

Focused Domain Review: Systems, Structure, and Site

Objective. Students will answer timed, domain-specific practice sets for structure, roofing, electrical, plumbing, HVAC, interiors, and site/grounds at a rate of 75% or better per domain, demonstrating mastery of the technical content most heavily weighted on all three exams.

⚠ Pending professional review

This lesson, its worked examples and its practice questions has not yet been verified by a credentialed professional in the field or by a certification or approval body. It is a study draft and may contain errors. Do not use it as instructions for work on a job site or on live equipment. Always follow your instructor, your supervising professional, and current official references and regulations.

VoTechWorks program approval and accreditation are still in progress. Credentials are issued only by the certifying bodies named in each program, after their own exams.

Why Domain Mastery Matters Before Exam Day

All three credentials you are preparing for—InterNACHI CPI, ASHI ACI, and your State Home Inspector License—test the same core technical territory: structure, roofing, electrical, plumbing, HVAC, interiors, and site/grounds. Each exam weights these domains differently, but none ignores any of them. A score of 75% or better in every domain is your target today because that threshold closely reflects the passing standards of the actual credentialing exams and proves you have real competence, not just lucky guessing.

This lesson is about focused repetition. You will move through mini-lectures, timed practice sets, and peer quizzing. Every time you miss a question, that miss is data: it tells you exactly where to re-read the InterNACHI or ASHI Standards of Practice before your next attempt.

Structural Systems

The structure domain covers foundations (slab, crawlspace, basement), framing (platform and balloon), load-bearing walls, beams, columns, and connections. Common reportable defects include foundation cracks that are horizontal or stair-step in masonry (serious concern), evidence of settlement or heaving, deteriorated sill plates, notched or bored framing members that compromise structural integrity, and missing or damaged bridging.

Your job is to observe and report, not diagnose or engineer. When a condition exceeds your scope—say, a crack pattern you cannot fully evaluate—the correct language is: recommend evaluation by a licensed structural engineer. Inspectors do not repair, do not guarantee, and do not provide engineering opinions.

Safety note: In crawlspaces, always assess atmospheric hazards before entry. Ensure adequate ventilation. Wear appropriate PPE—knee pads, disposable coveralls, gloves, N95 or better respiratory protection in areas with mold or fiberglass insulation. Apply lockout/tagout protocols if you must isolate any energy source before accessing confined areas.

Roofing

Key areas: roof covering type and condition, flashing at penetrations and valleys, gutters and downspouts, ventilation, and skylights. Common defects include missing or lifted shingles, improper flashing laps, cracked or absent caulk at penetrations, granule loss on asphalt shingles, and inadequate attic ventilation causing moisture buildup.

Always note your vantage point in your report—walked the roof, viewed from eave, or viewed from ground—because your scope and reliability of findings differ by position. Roofs that are too steep, too wet, or too fragile to walk must be inspected from the safest accessible point.

Electrical Systems

Inspect the service entrance, main panel, branch circuits, wiring type, outlets, GFCI and AFCI protection, and visible fixtures. Common defects: double-tapped breakers (two conductors under one breaker terminal where not listed for it), missing knockouts, aluminum branch wiring without compatible devices, reversed polarity, missing GFCI protection in kitchens, bathrooms, garages, and exterior locations, and open junction boxes.

Critical safety rule: Inspectors do not remove dead-front covers in a way that creates an arc-flash hazard, and you should never work inside energized panels beyond what your training and SOP authorize. Use a non-contact voltage tester before touching any wire or terminal. PPE includes safety glasses and insulated gloves rated for the voltage level present.

Plumbing Systems

Cover water supply (material, pressure, visible leaks), drain-waste-vent (DWV) system, water heater, fixtures, and fuel gas distribution where visible. Common defects: galvanic corrosion at dissimilar metal joints, improper DWV venting (S-traps), water heater lacking a temperature-pressure relief (TPR) valve with a properly terminated discharge pipe, evidence of active or past leaks, and cross-connections between potable and non-potable water.

Run water at every fixture and observe drainage. Report slow drains and note the age and condition of the water heater, which typically has a service life of eight to twelve years (varies by type and maintenance—never state exact lifespans as guarantees).

HVAC Systems

Inspect heating and cooling equipment, distribution (ducts or piping), filters, thermostats, and exhaust. Common defects: dirty or missing filters, heat exchangers with visible cracks or corrosion (a serious safety concern—carbon monoxide risk), disconnected or leaking duct sections, absence of combustion air, and condensate drainage problems.

When a heat exchanger crack is suspected, always recommend evaluation by a licensed HVAC technician and flag the carbon monoxide risk prominently in your report. Always operate HVAC equipment through normal controls and report if a system does not respond.

Interiors, Site, and Grounds

Interiors include walls, ceilings, floors, windows, doors, stairways, railings, and insulation/ventilation in attics. Site and grounds include grading (slope away from foundation), driveways, walkways, retaining walls, vegetation proximity, and drainage.

Key defects: grading that slopes toward the foundation (major moisture intrusion risk), guardrails and stair rails that are loose or missing, windows that do not open or seal properly, and evidence of moisture intrusion at interior surfaces.

Using Your Domain Tracker Effectively

After each 25-question timed set, score it immediately and record the number correct in your domain tracker. Any domain below 75% (fewer than 19 of 25 correct) requires a focused 20-minute re-read of the relevant Standards of Practice section before your second attempt. Be honest with your tracker—it is your personal blueprint for exam-day success. Your instructor will review and sign off on all six domains before you advance to the next lesson.

Peer Flashcard Quizzing: What to Focus On

When building flashcards with your group, prioritize: (1) correct terminology (e.g., TPR valve, not pressure valve), (2) inspection sequence within a system, and (3) reportable-vs.-not-reportable distinctions. Exam writers frequently use plausible-sounding distractors that describe conditions an inspector would note but use the wrong terminology or assign the wrong severity. Knowing precise language is as important as knowing the technical content.

Key terms10

Standards of Practice (SOP)The written document published by InterNACHI or ASHI that defines exactly what a home inspector is required to inspect, report, and exclude from each inspection; the primary reference for both exams and for professional conduct.
Double-tapped breakerA condition in which two conductors are connected under a single breaker terminal that is not listed (rated) for more than one conductor; a commonly reportable electrical defect.
GFCI (Ground-Fault Circuit Interrupter)A device that detects small imbalances in current and trips quickly to prevent electrocution; required by modern residential standards in kitchens, bathrooms, garages, crawlspaces, and outdoor locations.
TPR Valve (Temperature-Pressure Relief Valve)A safety device on a water heater that opens automatically if water temperature or pressure exceeds safe limits; its presence, condition, and proper discharge pipe termination are always inspected and reported.
DWV (Drain-Waste-Vent) SystemThe network of pipes that removes wastewater and sewage from fixtures and vents sewer gases safely to the exterior; improper venting (such as an S-trap) is a common reportable defect.
Inspection scopeThe specific systems, components, and conditions an inspector is obligated to examine and report on under the applicable Standards of Practice; conditions outside this scope are excluded and should be noted as such.
Reportable defectA condition that, under the applicable Standards of Practice, requires the inspector to describe it in the written report because it is a safety hazard, significant deficiency, or requires further evaluation by a specialist.
GradingThe slope of the soil surrounding a structure's foundation; proper grading directs surface water away from the foundation to reduce moisture intrusion risk, and is a required site/grounds inspection item.
Heat exchangerThe metal component in a forced-air furnace that transfers heat from combustion gases to the circulated air; cracks or corrosion can allow carbon monoxide to enter the living space and must be reported as a serious safety concern.
Domain trackerA student record-keeping tool (spreadsheet or worksheet) used to log practice set scores by system domain, identify areas below the 75% threshold, and document re-read and re-attempt results before instructor sign-off.
In class: Instructor delivers rapid-fire mini-lectures (10–15 minutes each) on the highest-yield topics within each system domain—common defects, inspection scope and limitations, required reporting language—using real inspection photos and sample report excerpts from prior coursework; students annotate domain reference sheets as the lecture proceeds. · Students work through six 25-question timed practice sets (one per major system domain), score each set immediately, and enter results in the domain tracker; any domain scoring below 75% triggers a targeted re-read of the corresponding InterNACHI or ASHI standards section before the next set. · Small groups of two to three students quiz each other using flashcard decks they create during the session, focusing on terminology, inspection sequence, and reportable-vs.-not-reportable distinctions likely to appear as exam distractors.
Materials: Domain-specific practice question banks (instructor-prepared); InterNACHI and ASHI Standards of Practice; IRC overview handout (general residential code concepts, no specific section numbers memorized); inspection photo library from earlier courses; blank flashcard stock or digital flashcard app (e.g., Anki, free); domain-tracking spreadsheet; timer.
Check: Students must score 75% or better on each of the six 25-question domain practice sets; any domain below threshold requires a second attempt after a focused 20-minute re-read. The instructor reviews all domain trackers at the end of the lesson and signs off before Lesson 3. All six domains must be at or above 75% to proceed.

Practice check8

Answer each question, then check it. Nothing is recorded; this is your own practice.

Structural Systems / InterNACHI CPI & ASHI ACI
1. An inspector observes horizontal cracks running along the mortar joints of a poured concrete block foundation wall. What is the most appropriate action?
Electrical Systems / InterNACHI CPI & ASHI ACI
2. During an electrical panel inspection, an inspector finds two conductors landed under a single breaker terminal on a 15-amp breaker. The panel directory lists one circuit for that breaker. What should the inspector do?
Electrical Systems / State Licensing Exam
3. An inspector is testing a bathroom outlet and finds that plugging in a circuit tester causes the GFCI outlet in the garage—but not the one in the bathroom—to trip. What does this most likely indicate?
Plumbing Systems / InterNACHI CPI & ASHI ACI
4. A water heater's temperature-pressure relief (TPR) valve discharge pipe terminates six inches above the water heater pan. Why is this a reportable defect?
HVAC Systems / InterNACHI CPI & State Licensing Exam
5. During an HVAC inspection, the inspector observes visible rust streaks and a possible crack on the furnace heat exchanger. What is the correct reporting action?
Site and Grounds / ASHI ACI & State Licensing Exam
6. An inspector observes that the soil around a home's foundation slopes toward the structure on two sides. Under the Standards of Practice, what should the inspector report?
Exam Preparation / InterNACHI CPI & ASHI ACI
7. A student's domain tracker shows the following scores after the first round of 25-question sets: Structure 80%, Roofing 72%, Electrical 76%, Plumbing 80%, HVAC 68%, Interiors 84%. According to today's lesson protocol, what must happen before the student attempts those sets again?
Interiors / InterNACHI CPI & ASHI ACI
8. During the interiors inspection, an inspector notices a guardrail on a second-floor landing that wobbles noticeably when hand-tested. What is the appropriate inspector action?
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