Cassie Withrow

Executive Administrator+Administrative Services Manager

Excellent customer service comes naturally to Cassie, who approaches every task with a can-do attitude. As Executive Administrator, she enjoys working with people that encourage her and test her limits but allow her to have fun along the way. She manages her time—and many others’—with extraordinary ease and keeps things running like a well-oiled machine. Outside the office, you’ll find Cassie hiking, exploring the city, and when the sun comes out, boating on Lake Washington—all with her husband and pups by her side.

Jeff Angehrn

Senior Construction Engineer

Jeff’s building career began in 1995 and he’s simply one of the best when it comes to complex structures; it’s been said that he’s memorized every detail of every sheet of every project he’s worked on. Plus, he’s repeatedly recognized by his teammates as an exceptional mentor. He holds a BS in Construction Management from Central Washington University. Off the jobsite, Jeff’s an adventurous spirit who enjoys time with family and friends, traveling, boating, snowmobiling, off roading, fishing, and hunting in the remote wilderness.

Sean Royal

Project Engineer

Sean recently joined GLY after completing two internships which gave him firsthand experience on high-stakes projects in the construction industry. With a degree in Construction Engineering Technology, he brings a solid foundation of technical knowledge and hands-on experience to his role as Project Engineer. In this capacity, he handles key responsibilities in trade management, overseeing work scopes, ensuring quality and safety compliance, and supporting project scheduling and budgeting. A Kirkland native, Sean enjoys spending his free time on Lake Washington, hitting the golf course, or experimenting with new recipes in the kitchen.

Laura Ovsak

Project Manager

RA, AIA, LEED Green Associate

Laura joined the GLY team in 2017 after spending five years with architecture and engineering design teams. Her varied design experience provides a deep understanding of the design process, and a fluency in the design language. Having worn many hats at GLY, she has developed a diverse skillset, carrying many projects through their phases. Laura recently completed the process of becoming a licensed architect!

Ronnie Dunham

Project Engineer

Ronnie developed an early curiosity for construction, inspired by his father, who worked as president of a Seattle-based glass company and shared stories about the buildings he helped bring to life. Today, Ronnie focuses on relationship development within the industry, where he enjoys connecting with people and learning from their diverse experiences and perspectives. Outside of work, he stays active snowboarding, surfing, and playing soccer–and has even gone shark diving and can juggle.

Monty Kilcup

Principal

Monty brings tremendous energy and ingenuity to his clients. He built his career at GLY by delivering creative, value-based preconstruction services, and accurate, timely estimating based on his deep knowledge of current market unit pricing and trends in commodity pricing. Monty works closely with an agile group of construction management, design, and craft professionals who flex to the ever-evolving needs of a project. He is a specialist in the occupied environment, always thinking outside project confines to develop innovative solutions.

Nate Hill

Senior Project Safety Manager

OSHA Certified CSHS, CHST

Nate is serious about safety. With 20 years of industry experience, he brings deep expertise in safety leadership and risk management to GLY projects of all shapes and sizes. He oversees jobsite safety programs and leads companywide training, staying ahead of evolving standards and protocols. Nate believes safety is fluid—requiring constant awareness, adaptability, and accountability.

An OSHA-certified Construction Safety + Health Specialist [CSHS] and Construction Health +Safety Technician [CHST], his credentials run long [and impressive]. Outside of work, he’s also a certified diver and lifelong animal lover. When he’s not focused on keeping people safe, you’ll find him surrounded by five wiener dogs, two cats, and one very sassy Norwegian Fjord horse.

Steven Siler

General Foreman

Steven is a detail-oriented professional known for his resourcefulness, problem-solving abilities, and strong communication across diverse teams. With experience leading work, maintaining schedules, and overseeing quality assurance, he brings a well-rounded, hands-on approach to every project. Steven’s career began with lutherie—the art of crafting stringed instruments—which sparked his passion for woodworking and led him to run a custom cabinet business in Arizona for over a decade. After relocating to the Seattle area, he joined the Carpenters Union in 2016 and continues to build a career grounded in craftsmanship and service. Outside of work, Steven is an accomplished musician who plays drums for the Seahawks [while playing a wide variety of other instruments at home as well] and has traveled to over 24 countries.

Dwight Hansch