Based on a large survey of only verified customers, only companies rated Highest in Quality and Helpful Expertise® earn the prestigious Diamond Certified award.
PETALUMA, Calif., Sept. 30, 2026 — Diamond Certified Resource has announced that four companies earned the prestigious Diamond Certified award in September 2026 by scoring Highest in Quality and Helpful Expertise: Brownstein Construction Inc., Chase Electric, Finest Precision Setters Inc. and Valdivia Roofing.
The Diamond Certified Research Team’s methodology ensures only a large, random sample of verified customers are surveyed, which produces the most accurate ratings of local companies available. The team conducts a 12-step rating and certification process that identifies companies delivering high quality and Helpful Expertise to their customers. The process includes collection of a large, random sample of customers; confidential telephone and email surveys of real customers; and verifications of state licenses, insurance, and business practices.
The research team produces a final Diamond Certified Research and Ratings Report. Only companies scoring 90 or above on a 100 scale are rated Highest in Quality and Helpful Expertise and earn Diamond Certified. If a company falls short of these standards, it does not earn Diamond Certified, regardless of how much it’s willing to pay. Qualified companies agree to follow the Diamond Certified Customer Satisfaction Principles and participate in mediation if needed, and they’re backed by the Diamond Certified Performance Guarantee. Ongoing surveys and monitoring help ensure continued high customer satisfaction by Diamond Certified companies.
“Earning Diamond Certified is a meaningful achievement because most companies can’t qualify,” says Greg Louie, founder and CEO of American Ratings Corporation, creator of Diamond Certified Resource. “These four companies have demonstrated the quality, Helpful Expertise and customer commitment required to earn the prestigious award.”
Every Diamond Certified Research and Ratings Report includes detailed statistical results (such as average satisfaction scores and response distributions), verbatim customer survey responses and visual charts that clearly present the findings. “Our Report shows each customer’s rating on a 1 – 10 scale of the company’s quality, whether they would hire the company again, if the company provided Helpful Expertise and verbatim answers to open-ended survey questions, which adds context to our research-grade report,” says David Pak, Director of Ratings at American Ratings Corporation.
Here’s more information about the four companies that earned Diamond Certified in September 2026:
Brownstein Construction Inc.
Brownstein Construction Inc. remodels kitchens and bathrooms, builds custom homes and accessory dwelling units (ADUs), and provides other construction services for residential and commercial clients in Marin and Sonoma Counties. The family-owned company has the in-house capabilities to manage every phase of the construction process, from the initial designs to the finishing touches.
Chase Electric
Chase Electric provides a wide range of electrical repair and installation services for residential and commercial clients in Contra Costa and Alameda Counties. The family-owned company has the training and equipment to take on all types of projects, from basic panel upgrades to complete home rewires, and it also installs lighting systems in a variety of interior and exterior applications.
Finest Precision Setters Inc.
Finest Precision Setters Inc. provides a wide range of general contracting and remodeling services for residential and commercial clients throughout Alameda County. The company works on everything from kitchen and bathroom remodels to room additions and custom homes, and it’s also qualified to handle specialized aspects of the construction process like framing, roofing, and tile and stone fabrication.
Valdivia Roofing
Valdivia Roofing provides a wide range of roofing services for homeowners in Monterey, Santa Cruz and Santa Clara Counties. In addition to replacing, maintaining and repairing all types of roofing systems (including asphalt shingle, metal, TPO, cedar shake and slate), the company is qualified to repair chimney flashing, install gutters and gutter guards, and more.
It’s easy to find top rated companies in the San Francisco Bay Area and Other Areas on Diamond Certified Resource.
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About American Ratings Corporation
American Ratings Corporation (ARC), the creator of Diamond Certified Resource, the source for consumers who love quality local companies, rates local companies by surveying only their verified real customers to produce the country’s most accurate ratings of local companies. It also creates deeply researched company reports and consumer guides that give consumers the best companies plus the best advice for choosing a local Auto, Home, Health or Personal service type of company.
Only companies rated Highest in Quality and Helpful Expertise® earn Diamond Certified and are backed by their Performance Guarantee. All their deeply researched reports and guides are available for free at diamondcertified.org. They also produce an annual, full-color, printed Diamond Certified Directory with 840,000 copies published in 9 geographic zones in the Greater San Francisco Bay Area. Each April, these are mailed for free to their 182,000 Diamond Certified Preferred Members and selected homeowners and companies.
SOURCE American Ratings Corporation
