ASHI (American Society of Home Inspectors) and InterNACHI (International Association of Certified Home Inspectors) are the two largest home inspector certifying bodies in North America. Both publish a Standards of Practice and a Code of Ethics, and both require training and exams. Because California has no state license for home inspectors, the membership a San Diego inspector holds is one of the few objective credentials you can actually verify.
Why certification matters more in California
More than 30 states regulate home inspectors with a license, mandatory hours, and a state exam. California is not one of them. There is no California Bureau or board that issues a “home inspector license,” and no state-required test before someone calls themselves a home inspector here. The state’s Business and Professions Code (the Home Inspector law, sections 7195-7199) does define what an inspection is and forbids conflicts of interest – for example, an inspector can’t also bid to do the repairs – but it does not set a competency bar or require any credential.
That gap is exactly why a certifying body matters. When the state won’t vouch for an inspector’s training, the inspector’s professional association becomes the closest thing to a quality floor. A current ASHI or InterNACHI membership tells you the person completed coursework, passed a national exam, and agreed in writing to follow a published standard and ethics code – things California law never asks for. It’s a starting filter, not a guarantee, but in an unregulated market it’s a meaningful one. Our deeper breakdown of how to vet credentials lives in our guide to choosing a San Diego home inspector.
What ASHI brings to the table
Founded in 1976, ASHI is the oldest national home inspector organization in the U.S., and its name carries weight with many real estate agents and consumers. ASHI is best known for tiered membership. New members start as Associates, and the top tier – the ASHI Certified Inspector (ACI) – requires passing the National Home Inspector Examination, completing a set number of fee-paid inspections (historically 250), and submitting inspection reports for peer verification against the standard. ASHI also requires ongoing continuing education to stay current.
The strength of the ASHI model is that “ACI” is a high bar that signals real field experience, not just a passed test. The trade-off is that an inspector listed as an ASHI member may be at any tier, so the label alone doesn’t tell you whether they’ve done 5 inspections or 5,000. If you’re comparing ASHI inspectors, it’s worth asking specifically whether they hold the ACI designation and how many inspections they’ve completed.
What InterNACHI brings to the table
InterNACHI, founded in 2006, is now the largest inspector association in the world by membership. Its model leans heavily on structured, repeatable training. To become a Certified Professional Inspector (CPI), a member must pass the InterNACHI Online Inspector Examination, complete required courses, agree to the InterNACHI Standards of Practice and Code of Ethics, and commit to continuing education every year. InterNACHI is known for its enormous free training library, mock inspections, and specialty courses on roofing, plumbing, electrical, and more.
The strength of the InterNACHI model is depth and consistency of education plus a single, clear designation – CPI – that every certified member shares. Critics point out that much of InterNACHI’s certification is achievable online, which is why the experience question still matters: ask any CPI how many inspections they’ve personally performed in your area. The credential confirms training and ongoing education; the inspector’s local track record fills in the rest.
Standards of practice and ethics: more alike than different
Here’s the part that surprises a lot of buyers. The ASHI and InterNACHI Standards of Practice are largely parallel documents. Both define a home inspection as a visual, non-invasive examination of the readily accessible systems and components of a home – roof, structure, exterior, plumbing, electrical, heating, cooling, interior, insulation, and ventilation. Both spell out what the inspector will report on, and both list clear exclusions: inspectors don’t move heavy furniture, take apart equipment, predict how long a component will last, or guarantee anything.
The exclusions are important because they’re the same things California’s general inspection scope leaves out, regardless of association. A general inspection does not include a termite or wood-destroying-organism report (that’s a licensed pest control operator), and it doesn’t confirm mold, asbestos, lead, or radon – an inspector can flag visual signs, but confirmation needs a specialist and lab testing. A home inspection also doesn’t replace a licensed electrician, plumber, or structural engineer; when something needs that level of evaluation, a good report says so and refers you out.
Both ethics codes prohibit the most damaging conflict of interest in this trade: an inspector can’t financially benefit from finding (or hiding) defects, and shouldn’t perform repairs on a home they inspected. That mirrors California law – so on ethics, ASHI and InterNACHI are aligned with each other and with the state.
So which certification is “better”?
Honestly, neither one wins outright. A diligent, experienced inspector under either standard will give you a thorough, fair report. A weak inspector can hold a membership card and still do shallow work. The certification is a filter, not the finish line. What actually separates good inspections from bad ones is the inspector’s experience, the quality and clarity of their reports, their knowledge of local housing stock, and whether they’ll walk you through the findings.
That local-knowledge piece is real in San Diego County. The defects that show up here – corrosion on coastal homes, aging electrical panels in older neighborhoods, clay-soil foundation movement inland, and Mediterranean-climate roofing issues – reward an inspector who has actually worked these properties, not just passed an exam. Ask any candidate, ASHI or InterNACHI, how many homes like yours they’ve inspected in your specific area.
Where The Real Estate Inspection Company stands
Our owner and lead inspector, Joseph Romeo, is an InterNACHI Certified Professional Inspector (CPI), which means he meets InterNACHI’s exam, training, ethics, and annual continuing-education requirements. He also holds a California CSLB General Contractor license (#1113143) – a construction-side credential that helps when judging how a defect was built and what a real repair involves. You can read more about our background and approach on our about us page.
When you’re vetting any inspector in San Diego, do this: confirm the certification is current (both associations let you look members up), ask how many inspections they’ve completed locally, and request a sample report so you can see exactly what you’ll receive. A real credential plus real local experience plus a report you can understand – that’s the combination that protects you, whichever letters come after the inspector’s name.
Have questions about your San Diego purchase, or want to book? Reach our team through our contact page and we’ll walk you through what your inspection will cover.
