- Passing requires a scaled score of 500 on a 200-800 range, not a raw percentage correct.
- The exam has 200 questions (175 scored, 25 unscored pretest) with four hours to finish.
- Property and Building Inspection/Site Review carries 70% of the content weight - study there first.
- Passing the NHIE alone does not make you an ASHI Certified Inspector; 250 inspections and five reports are also required.
What "Passing" Actually Means on the NHIE
Every candidate pursuing the ASHI Certified Inspector (ACI) credential must clear the National Home Inspector Examination (NHIE), developed by the Examination Board of Professional Home Inspectors (EBPHI). The passing standard is a scaled score of 500. This single number is the entire bar - there's no separate cutoff per domain, and you don't need to "pass" Property and Building Inspection/Site Review and Professional Responsibilities independently. You need the composite scaled score to land at 500 or above.
This matters because candidates often assume a passing score works like a school grade - get 70% or 80% right and you're through. That's not how the NHIE is scored, and misunderstanding this can lead to wasted study time on the wrong sections. If you haven't yet mapped out how the exam content breaks down, the ACI Exam Domains Guide is a useful companion to this article before you dive into scoring mechanics.
Inside the 200-Question Format
The NHIE is delivered as a 200-question, multiple-choice exam:
- 175 scored questions that count directly toward your result
- 25 unscored pretest questions mixed in without identification, used by EBPHI to evaluate future exam items
- Four hours total testing time
- Closed-book format - no personal notes, study guides, or calculators allowed at the testing center
Because the 25 pretest questions are unmarked and indistinguishable from scored ones, you have to treat every single question on the screen as if it counts. There's no way to skip or rush through a block assuming it's "just pretest." This blended design is one reason candidates researching how hard the ACI exam really is come away describing it as more mentally taxing than a straightforward 175-item test - the extra 25 questions stretch your endurance across all four hours without any signal of which ones are unscored.
Testing is computer-based and proctored. PSI administers the exam in most U.S. states, while Pearson handles delivery for select state programs. Regardless of vendor, the content outline and question style are standardized nationally.
Key Takeaway
Practice under closed-book, timed conditions using full-length simulations at the practice test platform so the four-hour pacing and no-notes restriction feel familiar on exam day, not jarring.
Why 500 Isn't a Percentage
A scaled score converts your raw number of correct answers into a standardized figure on a 200-800 range, adjusting for the relative difficulty of the specific question set you received. Two candidates who answer a different number of questions correctly could both land at exactly 500, because the underlying item difficulty differed between their forms.
The practical implication: you can't calculate "how many questions I need right" with simple arithmetic, and you shouldn't chase a percentage target while studying. Instead, focus on breadth of mastery across all three domains, since the scaling formula rewards consistent competency rather than being lucky on a handful of easy items.
Domain-by-Domain Breakdown
The NHIE content outline (effective April 1, 2024, per Pearson's official documentation) organizes every scored question into three domains. Because the passing score is a single composite figure, the smartest scoring strategy is to allocate study time in proportion to each domain's weight - not equally across all three.
| Domain | Weight | What It Covers |
|---|---|---|
| Property and Building Inspection/Site Review | 70% | Electrical, structural, roofing, HVAC, plumbing, life-safety, EV service equipment, smart-home systems |
| Analysis of Findings and Reporting | 20% | Interpreting inspection observations and translating them into accurate written reports |
| Professional Responsibilities | 10% | Ethics, standards adherence, and professional conduct obligations |
Domain 1: Property and Building Inspection/Site Review (70%)
This domain carries more than two-thirds of the exam's weight, making it the single highest-leverage area for improving your scaled score. Candidates need working knowledge across multiple building systems, not just one specialty.
- Electrical systems - panels, wiring methods, grounding, and circuit issues
- Structural components - foundations, framing, and load paths
- Roofing, HVAC, and plumbing systems and their common failure points
- Life-safety features, including detection and egress considerations
- Newer content areas: electric vehicle service equipment and smart-home inspection issues
Domain 2: Analysis of Findings and Reporting (20%)
This section tests whether you can move from observation to accurate documentation - a skill that mirrors the five compliant inspection reports ACI candidates must eventually submit for certification review.
- Correctly categorizing severity and safety implications of findings
- Translating field observations into clear, defensible report language
- Avoiding overstatement or omission in written conclusions
Domain 3: Professional Responsibilities (10%)
The smallest domain by weight, but it directly overlaps with ASHI's Code of Ethics, which every ACI-certified inspector must continue to follow after passing.
- Scope-of-inspection boundaries and disclosure obligations
- Conflict-of-interest and ethical conduct scenarios
- Standards-of-practice compliance in day-to-day inspection work
For a deeper walkthrough of how these three areas interact and where candidates commonly lose points, the full ACI Exam Domains Guide breaks each one down question-type by question-type.
Registration, Fees, and Retake Mechanics
Understanding the money and logistics side of the exam prevents avoidable surprises on test day:
- The standard NHIE fee is $225 per attempt in most U.S. states.
- ASHI's certification application fee is a separate $449 charge, distinct from the exam fee itself.
- Testing is proctored and computer-based, delivered through PSI in most states and Pearson in select state programs.
- The exam is strictly closed-book: no personal notes, printed materials, or calculators are permitted inside the testing center.
Because the exam fee is charged per attempt, a retake carries a real cost - which makes over-preparing on Domain 1 topics before your first sitting far cheaper than paying $225 again. If you want the complete cost picture, including how the $449 application fee interacts with the exam fee and other certification expenses, see the ACI Certification Cost Breakdown.
Building a Domain-Weighted Study Timeline
Generic study techniques only make sense once they're mapped to the NHIE's actual weighting. Since Property and Building Inspection/Site Review is 70% of the exam, it deserves roughly seven times the study attention of Professional Responsibilities. Here's how that translates into a focused review schedule:
Property and Building Inspection/Site Review
- Work through electrical, structural, roofing, HVAC, and plumbing systems in depth
- Add EV service equipment and smart-home inspection topics - newer content areas candidates often underestimate
- Run timed practice sets focused only on Domain 1 questions
Analysis of Findings and Reporting
- Practice converting raw field observations into written report language
- Review how severity and safety implications should be documented
Professional Responsibilities
- Study ASHI's Code of Ethics and standards-of-practice boundaries
- Work through conflict-of-interest and disclosure scenarios
Full Simulation & Review
- Take full-length, closed-book, four-hour practice exams under real timing conditions
- Revisit missed questions by domain to see where your scaled score is likely weakest
This weighted approach - heavy on Domain 1, moderate on Domain 2, light but not skipped on Domain 3 - is the core methodology detailed in the ACI Study Guide for passing on your first attempt. Running full practice exams at the practice test platform during weeks five and six is the most direct way to gauge whether your scaled-score trajectory is heading toward 500.
Passing the NHIE vs. Earning Full ACI Certification
A scaled score of 500 gets you past the examination requirement, but it does not by itself make you an ASHI Certified Inspector, and it does not confer a state home inspector license. Full ACI certification also requires:
- At least 250 fee-paid home inspections that comply with ASHI's Standard of Practice
- Five compliant inspection reports submitted for review and verification
- Ongoing adherence to ASHI's Code of Ethics
Once certified, maintaining the ACI credential requires 20 ASHI continuing education credits annually plus continued compliance with professional standards. The exam is a gate, not the finish line - the full picture of prerequisites is covered in the ACI Requirements guide, and it's worth reading before you assume passing the NHIE alone completes the process.
Key Takeaway
Treat the 500 scaled score as step one of a multi-part certification path - the 250 inspections and five submitted reports come after, not instead of, the exam.
If you're still weighing whether the time and cost involved are worthwhile relative to career outcomes, the ROI analysis on ACI certification and the ACI salary guide both dig into that question in more detail than a scoring article can cover.
FAQ
You need a scaled score of 500 on the 200-800 scale. This is a composite score across all three domains, not a domain-by-domain minimum.
No. The exam only has 200 questions total (175 scored, 25 unscored pretest). The 200-800 range is a scaled score, not a raw count, so it adjusts for question difficulty rather than reflecting a direct percentage.
No. Passing is based on your overall scaled score. There's no published requirement to hit a minimum threshold within Property and Building Inspection/Site Review, Analysis of Findings and Reporting, or Professional Responsibilities individually.
Not by itself. Full ACI certification also requires 250 fee-paid compliant inspections, five submitted compliant reports, and adherence to ASHI's Code of Ethics, in addition to the exam.
No. The NHIE is closed-book. Personal notes, study materials, and calculators are all prohibited at the proctored testing center.