Our Team

Your Partners In Success

With our team of highly dedicated and experienced professionals, and with our client as our partner, there is nothing we cannot achieve together.


Larry Debb

President & Founder

As president and founder of GSP Development, Larry Debb brings over 40 years of real estate construction, development, and ownership experience.  He is extensively involved in all aspects of GSP Development’s operations, and he is widely recognized for his ability to provide innovative solutions to complex problems.  In 2006, Larry co-founded GlenStar Properties, which today owns and manages over 6 million square feet of high quality office space in Illinois and Texas.  He served as a director of GlenStar, until his retirement in 2017. Larry has been involved as an owner of over $1.5 billion of real estate in his career.

John Kosich

Head of Development

As a principal in GSP Development, and a 35 year industry veteran, John Kosich leads and oversees GSP Development’s entire development team and provides the knowledge, energy, and commitment to consistently deliver as promised.

Stephen Rankin


With over 45 years of experience, Steve Rankin provides extensive experience in urban design, master planning, site planning, and programming, as well as expertise in multiple project delivery modes including design-bid-build, design-build, and fast-tract construction.

Carrie McCormick

Residential Market Analysis

Carrie McCormick has more than 19 years of real estate expertise along with an unsurpassed reputation for quality, results-oriented service and support.  Her talents and on-target recommendations are always based on facts, reliable market analysis, and her vast knowledge of sophisticated marketing and current market trends.

Kevin Veon

Corporate Brokerage

With over 35 years of relationship-driven experience representing both landlords and tenants, Kevin Veon provides expert brokerage, consulting, and lease negotiation skills.

Geoff Dowling


Geoff Dowling has over 40 years of real estate experience in brokerage, consulting, development, corporate planning, and investment.  He provides unparalleled expertise for acquisitions.

John Siff


John Siff has been involved in the real estate industry for over 40 years, and he has arranged, serviced, sold or purchased over $3.5 billion of real estate debt and equity during this time.

Bill Debb

Financial and Market Analysis

As a real estate professional for over 20 years, Bill Debb provides expert market research, data collection, report preparation, and financial analysis.