Diamond Properties’ Mark Blanford and Jeff Haack Receive CoStar’s Q2 2026 Power Broker Quarterly Deals Award
Award recognizes the lease of approximately 55,846 square feet at 600 Beta Drive in Mayfield Village, Ohio, to Mars
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Diamond Properties announced that Mark Blanford, Executive Vice President, and Jeff Haack, Leasing Manager, have been named winners of CoStar’s Q2 2026 Power Broker Quarterly Deals Award for completing a lease of approximately 55,846 square feet at 600 Beta Drive in Mayfield Village, Ohio, to Mars Electric.
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CoStar Group, Inc., a leading provider of commercial real estate information, analytics, and online marketplaces, recognizes Power Broker Quarterly Deals winners for significant commercial real estate transactions completed each quarter, based on price and square footage.
The transaction provides Mars Electric with a substantial location to support its operations while bringing a new tenant to 600 Beta Drive. The lease reflects Diamond Properties’ hands-on approach to marketing available space, understanding tenant requirements, negotiating terms, and creating leasing solutions that strengthen occupancy and long-term property performance.
Mark Blanford has been an integral member of Diamond Properties since the company’s inception. As Executive Vice President, he serves in several capacities, with a primary focus on leasing and tenant relations. Over the past 30 years, Mark’s efforts have helped Diamond Properties maintain consistently high occupancy rates throughout its portfolio.
Mark is known for developing creative solutions for tenants with specialized or challenging space requirements. He also plays an important role in maintaining strong tenant relationships and high levels of satisfaction while guiding tenants through lease renewals and changing market conditions.
Jeff Haack joined Diamond Properties on January 27, 2026, bringing five years of experience as a business owner and seven years of commercial leasing management experience. As Leasing Manager, he oversees the leasing process for a growing number of assigned properties, including marketing available spaces, generating and qualifying leads, coordinating property tours, negotiating lease terms, and finalizing transactions.
Jeff also researches market conditions, maintains relationships with tenants and brokers, and develops targeted outreach strategies designed to reduce vacancies and strengthen overall portfolio performance.
“Mark and Jeff’s recognition reflects the experience, persistence, and market knowledge they bring to the leasing process,” said Jim Diamond, CEO of Diamond Properties. “The lease with Mars Electric at 600 Beta Drive demonstrates our team’s ability to understand a tenant’s space requirements, structure a successful transaction, and create long-term value for our properties.”
Diamond Properties congratulates Mark Blanford and Jeff Haack on receiving the CoStar Power Broker Quarterly Deals Award for Q2 2026.
For more information about the CoStar Power Broker Awards, visit: https://www.costarpowerbrokers.com/about
About Diamond Properties
Diamond Properties is a commercial real estate company located in Mount Kisco, New York, that focuses on acquiring commercial properties with the potential for substantial improvement through hands-on property management, market repositioning, and capital upgrades. Founded in 1995, Diamond Properties has acquired more than 125 properties, including office, medical, industrial, retail, self-storage, residential, lodging, and land assets. The company currently owns more than 100 properties totaling approximately 17 million square feet across 13 states.
About CoStar Group, Inc.
CoStar Group (NASDAQ: CSGP) is a global leader in commercial real estate information, analytics, online marketplaces, and 3D digital twin technology. Founded in 1986, CoStar Group is dedicated to digitizing the world’s real estate and empowering people to discover properties, insights, and connections that improve their businesses and lives.
CoStar Group’s major brands include CoStar, LoopNet, Apartments.com, Homes.com, Domain, Matterport, STR, Ten-X, and OnTheMarket. Headquartered in Arlington, Virginia, the company serves clients around the world through its commercial and residential real estate platforms. For more information, visit CoStarGroup.com.
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