Joseph Derhake is a professional engineer who has built his life’s work at the intersection of engineering, environmental science, and real estate due diligence. He is best known as the founder and Chief Executive Officer of Partner Engineering and Science, Inc., a firm that helps clients understand and manage environmental risk whenever real properties are bought, sold, financed, or developed. Derhake holds a Bachelor of Science in Civil Engineering from Michigan State University and a Master of Business Administration from the University of Southern California.
A Company Born from Eight People and a Big Dream
Derhake’s career spans over 25 years as a professional engineer. In that time, he has worked on thousands of projects that involve environmental site assessments, site remediation, subsurface investigations, and more. His clients include big real estate investors, lenders, and corporations. He is licensed in many U.S. states as a civil engineer, which allows him to operate in varied jurisdictions.
What sets Joseph Derhake apart is how he turned a small team into a major player. When he founded Partner, it began with eight employees. Over time, he led it to a workforce of more than 1,200 people, operating across North America and Europe. He also led the company through several acquisitions, including LandAmerica Assessment Corporation in 2009 and Birdsall Services Group in 2013, which helped Partner expand its technical services and geographic reach.
Recognition That Goes Beyond Numbers
In recognition of his business achievements and influence, Joseph Derhake has been a finalist for awards such as EY Entrepreneur of the Year and named among the LA500 by the Los Angeles Business Journal. He has also been listed among the “Best Bosses in CRE” by Real Estate Forum, pointing to how people inside his firm view his leadership.
A Culture Built on Trust and Respect
One thing Joseph Derhake emphasises is culture. He believes a firm’s people are its greatest asset. He has tried to build a company where ideas are heard from every level, where strong values and collaboration matter, and where work-life balance is taken seriously. He has shared, in interviews, that the company follows a “no jerks” rule in hiring and firing. When crises hit, like during economic slowdowns or the COVID-19 pandemic, he acted to preserve jobs where possible, shared transparently with his team, and even reduced his own pay rather than letting people go.
Innovation in an Industry Slow to Change
Derhake also pushes for innovation. Under his leadership, the company launched Partner Valuation Advisors, which, within a short period, broke into the top 10 appraisal firms in the U.S. The firm has made tech investments, including tools and platforms for clients and internal teams, to make due diligence and environmental assessment more data-driven and efficient.
The Quiet Side of a Public Leader
Regarding his personal life, public records and interviews reveal less. He is located in or works out of Los Angeles, California. He has spoken about balancing life and work for his team, but there aren’t many details about his family, early childhood, hobbies, or private matters in the public domain.
What His Journey Really Means
In sum, Joseph Derhake is someone who took strong technical training, added business leadership, and then built an organization that aims to combine engineering rigour, environmental responsibility, and human-centred culture. He shows how engineering today is not just about soil tests and blueprints, it’s about people, risk, values, and long-term thinking.
