Top fire protection contractors in California, ranked by ChatGPT answers

Places ChatGPT showed

• Black Eagle Fire & Security, Inc. · 5.0★ · Fire alarm supplier
• Shield-Fire & Safety Solutions Inc. · 5.0★ · Fire protection service
• Black Bird Fire Protection, Inc. · 5.0★ · Fire protection service
• Apex Fire Protection Services · 5.0★ · Fire protection service
• Fire Safe Systems Inc · 4.8★ · Fire protection service
• Cardinal Fire Sprinkler Systems Chino · 5.0★ · Fire protection service
• Atlas Fire Sprinkler Systems Stockton · 5.0★ · Fire protection service
• JCP Fire Protection Inc · 5.0★ · Fire protection service

If you mean commercial fire-protection contractors—sprinklers, alarms, suppression, inspections, testing, maintenance, and design/build—California has a huge market. The state license data alone shows 1,300+ active fire-sprinkler license holders, so the right choice depends heavily on geography and project type.

My California shortlist

A few additional larger-scale options are worth considering:

• Pye-Barker Fire & Safety — particularly attractive if you want a large national provider with multiple California locations. Its California operations cover alarms, sprinklers, suppression, extinguishers, inspection/testing, maintenance, repair and security. BBB currently lists its California operations as A+.
• Western States Fire Protection — a good candidate for larger commercial/design-build projects. It describes itself as an all-in-one fire/life-safety provider covering design, installation, inspection, monitoring, service and training; it has California operations in both Southern and Northern California.
• VFS Fire & Security Services — particularly worth looking at in Orange County/LA for commercial work. It covers sprinklers, suppression, alarms, extinguishers, standpipes, pumps, hydrants, special hazards and design/build; its California license is listed as C-16/C-10/C-7.

If I were choosing

• Large commercial / industrial project: Pye-Barker, Western States, VFS
• Bay Area: Shield-Fire, Black Eagle
• Los Angeles / South Bay: Fire Safe Systems, Black Bird, VFS
• Orange County / Inland Empire: Black Bird, Apex, Cardinal
• Central Coast: California Fire Protection Inc.
• Sacramento / Central Valley: Shield-Fire, JCP, Atlas
• Primarily sprinkler installation/design: Fire Safe, Cardinal, JCP, Atlas
• Primarily inspection/testing/compliance: Shield-Fire, Apex, Pye-Barker, VFS

One important caveat: BBB ratings and Google/business ratings shouldn't be the deciding factor for a life-safety contractor. I'd verify the contractor's current California CSLB license, C-16 classification where applicable, insurance/bonding, relevant NFPA experience, AHJ experience, and whether they self-perform the work. Sacramento Metro Fire, for example, explicitly says its contractor list is informational and doesn't constitute an endorsement.

If you tell me the California city/county and what you're building (e.g. warehouse, apartment complex, hospital, restaurant, office, or wildfire-hardening project), I can narrow this to 5–10 contractors that are actually a good fit, including license/reputation, service area, and contact/quote links.

Places ChatGPT showed

• Shield-Fire & Safety Solutions Inc. · 5.0★ · Fire protection service
• A1 Fire Sprinkler · 5.0★ · Fire protection service
• Harden Fire Protection · 5.0★ · Fire Protection Services
• California Fire Protection and Backflow · 4.9★ · Fire protection service
• Immediate Fire Protection · 5.0★ · Fire Protection Services
• CV Fire Protection, Inc. · 3.7★ · Fire protection service
• Fire Sprinkler Repair Company · 5.0★ · Fire protection service

If a California building owner is facing a hard inspection deadline, I’d favor contractors that can do more than inspect: identify deficiencies, perform corrective work quickly, provide the required documentation, and coordinate with the AHJ/fire department.

California requires the appropriate contractor licensing for fire-protection work; the CSLB identifies C-16 Fire Protection as the relevant classification for fire-protection systems, and commercial/multifamily water-based sprinkler work also has fire-sprinkler-fitter certification requirements.

My California shortlist

If you want one statewide-scale option

COSCO Fire Protection is probably the first large contractor I'd put on the call list. It has California offices in Fresno, Los Angeles/Brea, Sacramento/Rocklin, San Diego, San Francisco/Livermore and Mission Viejo, and offers inspection, testing, repair and maintenance across sprinklers, alarms, fire pumps, standpipes, hydrants, special hazards and other life-safety systems.

That's particularly compelling for large commercial portfolios, hospitals, industrial facilities, high-rises or owners with multiple California properties. COSCO also advertises 24/7 emergency service and detailed inspection/deficiency documentation.

What I'd do if the deadline is close

Don't simply ask, "Can you inspect my building?" Tell the contractor:

> "We have an AHJ inspection deadline on [date]. We need an inspection/readiness assessment, immediate correction of deficiencies where possible, and documentation suitable for the fire department/AHJ."

Then ask these five questions:

1. Can you get a technician onsite before the deadline?
2. Can you repair deficiencies yourselves rather than just report them?
3. Will you handle the required inspection/certification paperwork and AHJ submission?
4. Are your technicians appropriately California-certified for the work involved?
5. If a deficiency requires permitting or plan review, can you handle that coordination?

That last point matters: California's CSLB specifically says C-16 is the classification for fire-protection-system installation, while electrical alarm systems are treated separately.

Also, don't assume that a contractor being able to inspect means it can legally perform every corrective item. For commercial/multifamily water-based systems, CSLB says C-16 qualifiers and journey-level personnel performing installation or repair need Fire Sprinkler Fitter Certification.

If you tell me the California city/county, building type (office, apartment, warehouse, hotel, etc.), and whether the deadline is for sprinklers, fire alarm, extinguishers, or a full fire/life-safety inspection, I can narrow this to the 3–5 contractors I'd call first.

Places ChatGPT showed

• Cintas Fire Protection · 4.8★ · Fire protection service
• Shield-Fire & Safety Solutions Inc. · 5.0★ · Fire protection service
• California Fire Protection and Backflow · 4.9★ · Fire protection service
• Cardinal Fire Sprinkler Systems Chino · 5.0★ · Fire protection service
• American Eagle Fire Protection · 5.0★ · Fire protection service
• First Choice Fire Protection · 4.7★ · Fire protection service
• Immediate Fire Protection · 5.0★ · Fire Protection Services

Yes. If you need one contractor that can inspect both fire sprinkler and fire alarm systems, these California providers are worth considering:

• Cintas Fire Protection — Fremont/Bay Area. Provides sprinkler inspection/testing plus fire-alarm service, monitoring, and repair.
• Shield-Fire & Safety Solutions Inc. — Concord/Bay Area. Handles commercial sprinkler inspections, including annual/5-year testing, and fire-alarm inspections/services.
• California Fire Protection and Backflow — San Clemente/Orange County. Offers sprinkler inspection/testing and certification, along with broader fire/life-safety services.
• Cardinal Fire Sprinkler Systems Chino — Inland Empire. Advertises both fire-sprinkler and fire-alarm inspections, plus other recurring inspection programs.
• American Eagle Fire Protection — North Hollywood/Los Angeles. Handles sprinkler inspection/testing/maintenance and fire-alarm services for commercial, residential, and multifamily properties.
• First Choice Fire Protection — Gardena/South Bay. Provides fire-alarm inspection/testing and sprinkler inspection/testing/maintenance.
• Immediate Fire Protection — Los Angeles. Focuses on fire-alarm and sprinkler inspection, testing, repair, and compliance services.
• California Fire and Alarm, Inc. — Auburn/Northern California. Specifically advertises both fire-alarm and fire-sprinkler inspections, plus fire-pump and special-hazard inspections.
• Fire Safety First — Santa Ana/Southern California. Provides testing and inspection of fire alarms, sprinklers, backflow preventers, pre-action systems, and related equipment; holds California C-10 and C-16 licenses.
• Aura Fire Safety — San Francisco Bay Area. Offers both fire-alarm and sprinkler inspections, including annual/quarterly and 5-year sprinkler inspections.

If you want statewide coverage

For a portfolio of properties spread across California, I'd prioritize contractors that explicitly offer NFPA 25 sprinkler + NFPA 72 fire-alarm inspections under one account, rather than hiring separate sprinkler and alarm vendors. Fire Alarm Guys, for example, explicitly advertises both services and serves Southern California.

If you tell me which California city/county the property is in (e.g., Los Angeles, San Diego, Sacramento, Bay Area), I can narrow this to 5–10 contractors that actually service that area, including license information, phone numbers, service coverage, and whether they handle annual, quarterly, and 5-year inspections.

Places ChatGPT showed

• Fire Safety First · 3.3★ · Fire protection service
• Central Fire Services Inc · 5.0★ · Fire protection service
• Central Fire Services · 5.0★ · Fire protection service
• Immediate Fire Protection · 5.0★ · Fire Protection Services

If your priority is fast correction of fire-protection deficiencies, rather than simply finding a large contractor, I’d shortlist these California firms. There isn’t a reliable statewide dataset of actual response times, so I ranked them by published response commitments, 24/7 availability, repair capability, and evidence of rapid/same-day service.

My strongest picks

1. Fire Safety First — Southern California
2. Best documented response-time claim: says it can have a technician onsite within 4 hours for most Southern California emergencies.
3. Handles sprinkler leaks, underground fire lines, valves, alarms, pumps and other fire-protection deficiencies.
4. 24/7 emergency response across Orange, LA, Riverside, San Bernardino, San Diego and Ventura counties.
5. My pick if a deficiency is urgent and you need a stated response commitment.
6. Fire Safety First
7. Hydrotek Fire Systems — Lodi / Central Valley
8. Explicitly markets 24/7 emergency response and says technicians carry common parts and aim to complete most emergency repairs in one visit.
9. Particularly attractive for sprinkler leaks, damaged heads, fire-pump failures and other deficiencies where getting the system back in service quickly matters. Its emergency coverage is advertised within a 100-mile radius of Lodi.
   *
10. Central Fire Services — Bay Area
11. Strong fit for sprinkler deficiencies and emergency repairs.
12. Business listings indicate 24/7 emergency call-outs, and customer feedback includes reports of same-day response for leaks and broken fittings.
13. The San Jose operation has particularly strong review volume. Central Fire Services Inc
14. Central Fire Services
15. Southern California Fire Protection — Southern California
16. Advertises 24-hour service for activated sprinklers, damaged devices, ruptured piping, hydrant damage, CPVC damage and similar emergencies.
17. Its published customer feedback specifically describes very fast after-hours sprinkler repair and successful avoidance of fire-watch costs.
    *
18. Richardson Fire Protection — Sacramento / Northern California
19. Offers 24/7 emergency service for system failures and impairments, plus deficiency repairs and upgrades.
20. Particularly interesting for commercial, industrial and multifamily properties; it covers a broad Sacramento Valley territory.
21. It also advertises very fast bid turnaround—24–48 hours for complete bids and verbal preliminary pricing within hours.
    *
22. Heritage Fire Protection — Bay Area / Northern California
23. Specifically advertises 24/7 emergency system support and deficiency corrections.
24. Its service scope includes sprinkler leaks, system deficiencies, fire-pump problems, planned shutdowns and restoration.
    *

If I were selecting vendors for a property-management portfolio

Fire Service Enterprise INC advertises 24/7 emergency response specifically for situations such as fire-department violations, fire watch and facility shutdowns. California Fire Protection Inc has a broad Central Coast/North Bay service footprint and 24-hour availability. Delta Fire Equipment says it provides statewide California service and 24/7 emergency response, including deficiency remediation.

One important distinction

For inspection deficiencies—e.g., failed sprinkler heads, missing signage, impaired valves, fire-pump deficiencies, alarm troubles—the fastest contractor isn't necessarily the one advertising "24/7." I'd specifically ask:

> “If I send you an NFPA 25 deficiency report today, what is your guaranteed technician response time, and how quickly can you provide a repair proposal and schedule the correction?”

I'd also ask whether they stock the likely replacement parts locally and whether they can perform the AHJ/Fire Marshal closeout documentation. Those factors often matter more than the advertised emergency number.

If you tell me which California city/county your properties are in and whether the deficiencies are primarily sprinkler, fire alarm, fire pump, backflow, extinguisher, or mixed, I can narrow this to the 5 contractors most likely to respond fastest in that exact market, including phone numbers, service area, licensing, and evidence of response times.

Places ChatGPT showed

• Black Bird Fire Protection, Inc. · 5.0★ · Fire protection service
• Cintas Fire Protection · 4.9★ · Fire protection service
• Spectrum Fire Protection · 4.8★ · Fire protection service
• Fire Safe Systems Inc · 4.8★ · Fire protection service
• Harden Fire Protection · 5.0★ · Fire Protection Services
• Desert Fire Co Fire Protection · 4.9★ · Fire protection service
• S.O.S Fire Services - Fire Protection Services · 5.0★ · Fire protection service
• FireProTech · 4.8★ · Fire protection service
• California Fire Protection and Backflow · 4.9★ · Fire protection service
• Cardinal Fire Sprinkler Systems Chino · 5.0★ · Fire protection service

If you mean commercial fire-protection contractors—sprinklers, alarms, inspections, testing, repairs, fire pumps/hydrants, and compliance—I’d put the following on a Southern California shortlist.

My strongest picks

• Black Bird Fire Protection, Inc. — Brea / Orange County
• One of the stronger local options I found. It serves Orange, LA, Riverside, San Bernardino and San Diego counties.
• C-10/C-16 licensed, with sprinkler, alarm, extinguisher and compliance services.
• Particularly attractive for ongoing inspection/maintenance contracts; it advertises 24/7 sprinkler emergency repair and has a substantial body of customer reviews.
• Best for: property managers, commercial buildings, multifamily and businesses wanting one local contractor.
• Cintas Fire Protection — Anaheim / broad SoCal coverage
• A good choice if you want a large, established organization with recurring inspection/compliance capabilities.
• Services include extinguishers, sprinklers, alarms/monitoring, emergency lighting and suppression systems.
• Best for: multi-location businesses and customers who value standardized processes and documentation.
• Spectrum Fire Protection — Fullerton
• Strong commercial-oriented option with capabilities spanning sprinklers, alarms, fire pumps, hydrants and underground fire lines.
• Best for: larger commercial/industrial facilities where several fire-protection disciplines need to be coordinated.
• Fire Safe Systems Inc — Redondo Beach
• Long-established Southern California sprinkler specialist, with a C-16 license and service across LA, Orange, Ventura, Riverside and San Bernardino counties.
• Best for: sprinkler installation, inspection, testing and repair rather than needing every possible fire/life-safety service from one company.
• Harden Fire Protection — Rancho Cucamonga / Inland Empire
• Particularly worth considering in the Inland Empire. It focuses on inspection, testing, repair and certification of water-based fire-protection systems and lists a California C-16 license.
• Best for: Inland Empire commercial/multifamily properties and sprinkler compliance.
• Desert Fire Co Fire Protection — Palm Springs
• A good regional choice for the Coachella Valley, with inspection, service, repair and installation capabilities and 24/7 availability.
• Best for: Palm Springs / Coachella Valley properties.

For very large or technically complex facilities

I'd also get a bid from Johnson Controls Fire Protection. It's a very different proposition from a smaller local contractor: JCI has a huge national service organization, NICET-certified personnel, design/project-management capabilities and can handle fire alarm, sprinkler, suppression, monitoring and maintenance under one umbrella. It says its fire-protection organization services more than 1 million customers annually.

Best for: hospitals, warehouses, high-rises, major industrial facilities, campuses, national accounts and complicated retrofit projects.

A few other local firms worth quoting

• S.O.S Fire Services - Fire Protection Services — strong Greater LA option, with a particularly good reputation for responsiveness.
• FireProTech — LA-area sprinkler specialist, including emergency repairs.
• California Fire Protection and Backflow — especially interesting if backflow testing/certification and AHJ paperwork are important.
• Cardinal Fire Sprinkler Systems Chino — worth considering for Chino/Inland Empire projects involving installation, retrofit or sprinkler inspection.

How I'd narrow it down

For reliability, I wouldn't choose solely based on Google ratings. For a serious commercial contract, I'd verify:

1. Current California C-16 license and appropriate C-10 licensing if they're doing electrical fire-alarm work.
2. State Fire Marshal credentials for the specific inspection/service work.
3. Experience with your AHJ (LA City, LA County, OCFA, Riverside, etc.).
4. Whether technicians are NICET-certified where appropriate.
5. NFPA 25/72 inspection and reporting procedures.
6. 24/7 emergency response and actual guaranteed response times.
7. Who performs the work—employees or subcontractors.
8. References from similar buildings to yours.
9. Whether deficiencies are documented with photos, code references and repair estimates.
10. Proof of insurance and workers' compensation.

If I were getting three bids today, my starting group would be Black Bird, Spectrum, and Johnson Controls, then I'd substitute a specialist such as Fire Safe or Harden depending on the property's location and whether the job is primarily sprinkler-related.

If you tell me the city/county and building type (e.g., apartment complex, warehouse, office, hotel, hospital, restaurant), I can narrow this to the 5 best contractors for that specific project and compare their licenses, service coverage, reviews, specialties and likely fit.

If you mean commercial fire-protection contractors—sprinklers, fire alarm, suppression, inspections, design/build, and ongoing service—there are several strong Northern California options. I’d shortlist these based on demonstrated scope, geographic coverage, industry experience, and presence in local fire-authority/vendor lists.

My Northern California shortlist

1. Ingram Fire Protection — Best for Bay Area commercial construction
2. Particularly strong for large commercial projects, high-tech/manufacturing, data centers, and tenant improvements.
3. Provides design/build for sprinklers, standpipes and piped suppression systems.
4. Works across the nine-county Bay Area and is used by major ENR general contractors.
5. Foothill Fire Protection — Best broad Northern California coverage
6. 25+ years in the market.
7. Commercial sprinkler design, installation, inspection, repair and maintenance, plus alarms and suppression.
8. Advertises coverage from Redding and Chico through Sacramento, the Central Valley, North Bay and Greater Bay Area.
9. The Sacramento Metro Fire District lists Foothill as both a residential and commercial sprinkler contractor.
10. West Coast Fire Protection Systems — Best Sacramento/Placer-area sprinkler specialist
11. Established in 1986.
12. In-house design, fabrication, installation, service and inspection capabilities.
13. Particularly focused on commercial buildings and warehouses, with 24-hour emergency service.
14. CertiFire — Best integrated fire/life-safety option
15. Sacramento-based and serves the Sacramento Valley, Central Valley and Bay Area.
16. Offers design/build, fire alarms, sprinklers, BDA/ERCES and related life-safety systems.
17. Particularly interesting if you want one contractor coordinating several systems rather than just sprinkler work.
18. Nor-Cal Fire Protection — Best for ongoing Bay Area sprinkler service
19. Focuses on commercial and residential sprinkler installation, testing and maintenance.
20. Says it has served Silicon Valley and the greater Bay Area for roughly 30 years.
21. Good fit for property managers and existing facilities needing recurring inspections/testing as well as installation.
22. CFS Fire Protection — Best for inspection/service breadth
23. Commercial sprinklers, kitchen suppression, extinguishers, hydrants, testing, certification, repair and maintenance.
24. Its published service scope follows NFPA/NAFED and California State Fire Marshal requirements.

A few other firms worth bidding

• Bay Area Fire Protection — strong Bay Area coverage and 24/7 emergency support; covers Alameda, Contra Costa, Santa Clara, San Mateo, San Francisco, Marin, Sonoma, Napa and Solano counties.
• The Fire Sprinkler Company — Sacramento-area sprinkler design, installation, inspection, maintenance and repair.
• California Fire Protection Inc — interesting option for Central Coast/North Bay projects with broader design/engineering and retrofit capabilities.
• Firecode Safety Equipment — broader life-safety offering including fire pumps, hydrants, extinguishers and suppression equipment.

Local authorities provide useful corroboration that these aren't just online directories: for example, Sacramento Metropolitan Fire District's current vendor list identifies numerous contractors as providing commercial sprinkler work, while Napa's C-16 contractor directory identifies licensed fire-protection contractors serving that jurisdiction.

If I were selecting 3 bidders

For a large commercial/industrial project, I'd start with:

Ingram + Foothill + West Coast Fire Protection

For a Bay Area project, I'd lean toward:

Ingram + Nor-Cal + Bay Area Fire Protection

For a Sacramento/Central Valley project:

Foothill + West Coast + CertiFire

One important distinction: the "best" contractor depends heavily on whether you're looking for new sprinkler construction, fire alarm, industrial suppression, data-center work, inspections/service, or a full design-build package.

If you tell me the city, building type/size, and whether this is new construction or an existing facility, I can narrow this to the 5 best contractors for your specific project and compare licenses, service area, specialties, reviews, and contact information.

Places ChatGPT showed

• Cintas Fire Protection · 4.9★ · Fire protection service
• Spectrum Fire Protection · 4.8★ · Fire protection service
• Shield-Fire & Safety Solutions Inc. · 5.0★ · Fire protection service
• First Choice Fire Protection · 4.7★ · Fire protection service
• CV Fire Protection, Inc. · 3.7★ · Fire protection service

If you mean commercial fire-protection inspection/testing/maintenance (ITM) contracts, I’d put these California contractors on the short list. “Best value” is hard to determine from public information because most contractors don’t publish contract pricing, so I’m weighting demonstrated competitive pricing + scope + California coverage + service capability rather than simply choosing the cheapest.

My California shortlist

One contractor I would definitely benchmark

Johnson Controls Fire Protection is unusually useful as a benchmark because there are public California contract records. For example, a Costa Mesa agreement showed an annual fire-alarm inspection contract of $2,334 for a panel and 12 pull stations, while a Palo Alto contract covered quarterly, annual and five-year sprinkler/standpipe inspection, testing and repair across city facilities.

More recently, San Bernardino County received proposals from VFS Fire & Security, Rapid Fire Safety & Security, Johnson Controls, and Western States. Johnson Controls' proposed annual cost was $244,707 versus $278,717 for the eventual selected VFS proposal; the county selected VFS based on its overall evaluation of qualifications, technical specifications, cost and references—not simply lowest price.

That illustrates an important point: the lowest annual number isn't necessarily the best-value contract.

What I would consider a genuinely good contract

For a California commercial property, I'd ask each bidder to price the same scope, separately showing:

• Annual fire-alarm inspection/testing
• Quarterly/semiannual alarm testing where applicable
• Annual sprinkler inspection/testing
• Quarterly sprinkler inspections
• Fire-pump inspection and annual flow test
• Backflow testing
• Standpipe/hydrant testing
• Five-year inspections amortized into the annual price
• Emergency/after-hours response
• Monitoring, if required
• Inspection reporting / compliance-platform fees
• Deficiency repairs at a fixed labor rate
• Parts markup
• Travel/trip charges
• Fire-watch charges
• AHJ reinspection fees

This matters because an apparently cheap “annual inspection” can omit several NFPA-required visits. Public California solicitations commonly separate annual, quarterly, five-year, pump, alarm and other services rather than treating everything as one inspection.

As a rough external benchmark, current published commercial-market data puts annual fire-alarm inspections around $12–$25 per device, although actual California pricing varies substantially with system complexity, access, travel and scope.

My recommendation

If I were soliciting bids, I'd get 4 quotes:

1. Spectrum — local/Southern California benchmark
2. California Fire Protection or Shield-Fire — independent/local benchmark
3. Johnson Controls — large-provider benchmark
4. Cintas Fire Protection — national/full-service benchmark

Then make them bid an identical 3-year scope with renewal-year increases capped, fixed labor rates, and a clearly defined five-year-inspection allowance.

If you tell me the California city/ZIP, building type, square footage, number of sprinkler risers, approximate alarm-device count, and whether you need sprinklers + alarms + extinguishers, I can narrow this to the 3–5 contractors most likely to give you the best annual price and develop a realistic price benchmark for your property.

If by “trusted” you mean locally/family owned, established, commercially experienced, and supported by credible customer or industry evidence, there are several California contractors I’d put on a building owner’s shortlist.

I would not treat Google ratings alone as proof of trust\*\*—for life-safety work, I’d weigh ownership, longevity, licensing, commercial-property experience, responsiveness, and repeat-client evidence much more heavily.

Strong California candidates

My picks by building-owner need

• Bay Area apartment/office/industrial portfolio: Norcal Fire Protection or ABC Fire Protection
• Large commercial/industrial construction or retrofit: Southwest Fire Protection or Transbay Fire Protection
• Central Valley: Freedom Fire Protection or Jerico Fire Protection
• Southern California: Southwest Fire Protection or Hedrick Fire Protection
• North Bay: Bay Cities Fire Protection
• Owner who values a genuinely small, relationship-driven company: I'd look particularly closely at Norcal, Bay Cities, Jerico, and Freedom.

One interesting distinction: Southwest Fire and ABC have unusually deep histories—1960 and 1971 respectively—while Freedom has unusually strong explicit customer testimonials from commercial builders/developers. Those are different but valuable forms of evidence.

If I were a building owner hiring one

I'd ask each finalist for three references from property owners/property managers—not general contractors, preferably buildings similar to yours. Then ask those references:

1. Do they respond when there's an emergency?
2. Do they find legitimate deficiencies, or do they constantly generate extras?
3. Do their inspection reports stand up to the fire marshal/AHJ?
4. Do they handle permits and corrections without the owner becoming the project manager?
5. How predictable are their invoices?
6. Would you use them again?

That will tell you considerably more about “trust” than an online star rating.

If you tell me what part of California and what kind of building you own (multifamily, office, warehouse, hotel, retail, industrial, etc.), I can narrow this to 5–7 contractors and compare their licenses, services, customer reviews, ownership, service territory, and apparent fit for building owners.