Every home inspector operates under a Standard of Practice (SOP)but most can't explain exactly what's required, what's excluded, or how their SOP compares to others. This confusion leads to lawsuits, missed defects, and angry clients. Whether you follow InterNACHI, ASHI, or state-mandated standards, this guide breaks down everything in plain English with actionable checklists you can use today.
What is a Home Inspection Standard of Practice? A Standard of Practice (SOP) defines the minimum requirements for a home inspection—what systems must be inspected, what methods to use, what's excluded, and what must be reported. The two main SOPs are InterNACHI (used by 26,000+ inspectors) and ASHI (used by 3,000+ inspectors). Many states have adopted modified versions as mandatory requirements.
Want SOP-compliant templates ready to use? HomeInspecto's checklists are pre-built around InterNACHI and ASHI standards—every required system covered, proper exclusions included.
InterNACHI vs ASHI Standards of Practice: Complete Comparison
The two dominant inspection standards in North America come from InterNACHI and ASHI. Here's how they compare across every major category:
Which SOP Should You Follow?
Follow your state's mandatory SOP first—it overrides association standards. If your state doesn't regulate, follow your association's SOP. If you're not a member of either, InterNACHI's SOP is freely available and more detailed.
Home Inspection Requirements by State (2026)
Each state has different licensing requirements. Find your state below:
State-Specific Templates Available
HomeInspecto offers templates customized for your state's specific SOP requirements. Free 7-day trial includes all state templates.
What Do Home Inspectors Have to Inspect?
Both InterNACHI and ASHI require inspection of these 10 systems:
What Is Not Included in a Home Inspection?
Understanding exclusions is critical for liability protection:
❌ Environmental
- Mold testing
- Asbestos
- Lead paint
- Radon
- Water quality
❌ Concealed
- Behind walls
- Underground
- Locked areas
- Blocked items
❌ Code/Legal
- Code compliance
- Permits
- Zoning
- Engineering
❌ External
- Pools/spas
- Septic interior
- Wells
- Outbuildings
❌ Specialty
- Security systems
- Central vacuum
- Elevators
- Solar panels
❌ Predictions
- Remaining life
- Future failures
- Repair costs
- Market value
Never Miss Required Items Again
HomeInspecto templates are built around SOP requirements—every system, every exclusion statement included.
Free SOP Compliance Checklist
SOP Compliance Checklist
Complete checklist covering all 10 required systems, limitation prompts, and exclusion templates.
SOP Violations That Lead to Lawsuits
E&O insurance data reveals the most costly mistakes:
Top 5 Lawsuit-Causing Violations
HomeInspecto's smart templates help you avoid lawsuit-triggering mistakes:
- Mandatory limitation fields — Can't skip documenting limitations
- Pre-approved narratives — No code language, no predictions
- Safety checklist prompts — Required GFCI, smoke detector fields
- Scope enforcement — Clear exclusions in every report
Home Inspection Standards: Common Questions
No—mold testing is explicitly excluded from both InterNACHI and ASHI Standards of Practice. Inspectors can note visible conditions that may indicate mold but cannot identify, test for, or confirm mold presence.
No—asbestos identification is excluded. Inspectors may note materials that commonly contain asbestos and recommend professional testing, but cannot confirm asbestos presence without lab analysis.
It depends on safety conditions. SOPs require roof inspection but don't mandate walking on the roof. Inspectors use the safest method—walking, ladder at eaves, binoculars, or drones.
Both cover the same major systems but differ in detail. InterNACHI (26,000+ members) has more detailed SOPs with specific component lists. ASHI (3,200+ members) uses broader language. Practical differences are minimal.
No—code compliance is explicitly excluded. Inspectors are not code officials and cannot determine code compliance. Instead, describe conditions: "GFCI protection not present—recommend electrician evaluation."
Not in standard inspections—pools are excluded. Many inspectors offer pool inspections as separate ancillary services with additional fees and agreements.
SOP-Compliant Templates, Zero Guesswork
HomeInspecto templates follow InterNACHI and ASHI standards. Every required system, proper exclusions, limitation documentation—all built in.
