Leadership
Matthew Zirkelbach
Co-Founder-
Matt Zirkelbach is Co-Founder of RunBrook and an entrepreneur with more than two decades of experience delivering high-performance building assets for owners and occupants. His work focuses on building practical solutions helping clients navigate complex requirements, achieve above-code performance, and reduce risk throughout the design and construction process.
Under his leadership, RunBrook has grown into a trusted partner for developers, builders, architects, and engineers across the United States. The company combines technical expertise, streamlined processes, and technology-enabled workflows to help clients reduce complexity, minimize risk, and achieve stronger project outcomes.
Matt also co-founded SustainaBase, a carbon accounting and sustainability data management software company designed to simplify environmental reporting and compliance. In 2024, SustainaBase was acquired by ISS Corporate, reflecting his ability to identify emerging market needs, build scalable solutions, and create value through both technology and professional services.
Today, Matt focuses on the strategic growth of RunBrook, with a particular interest in technology adoption, operational scalability, and long-term enterprise value creation. He believes that better buildings and better businesses are built the same way: through clear strategy, measurable results, and disciplined execution.
Daniel Denis
President-
Daniel Denis is President of RunBrook, where he leads the company’s technical operations, project delivery, and client service across building performance, energy compliance, green building certification, testing, and construction-phase sustainability support.
Danny brings more than 20 years of design and construction experience to RunBrook, with a background that spans design consulting, contracting, third-party inspection, energy modeling, and green building consulting. That cross-disciplinary experience gives him a practical understanding of how projects move from design through construction, and how to help teams solve compliance and performance challenges before they create delays, rework, or added cost.
Since joining RunBrook in 2021, Danny has helped strengthen the company’s role as a trusted partner to developers, builders, architects, engineers, and construction teams navigating increasingly complex code, certification, and performance requirements. His leadership is grounded in both technical expertise and clear communication, helping project teams align sustainability goals with construction schedules, budgets, documentation requirements, and final inspection needs.
Danny began working on green building projects in 2012 as an energy modeler for one of Miami’s leading mechanical engineering firms. He later became a Green Building Project Manager, leading LEED documentation efforts while continuing to develop his expertise in energy modeling and building performance. He went on to serve as an Energy Engineer and Consultant for a firm focused exclusively on green building consulting, where he supported projects across rating systems including LEED, FGBC, NGBS, and ENERGY STAR.
In addition to his role at RunBrook, Danny is active in Florida’s green building industry. He serves as President of the Florida Green Building Coalition and has also served as Chair of FGBC’s High-Rise Standards Committee. His current and past professional credentials include LEED AP BD+C, LEED Green Rater, FGBC Certifying Agent, NGBS Verifier, RESNET HERS Rater, ENERGY STAR Verifier, NGBS Master Verifier, and WRI Verifier.
At RunBrook, Danny’s work reflects a practical belief: high-performing buildings require more than good intentions. They require strong technical guidance, disciplined execution, and a team that understands how to move projects through compliance, certification, testing, and final approval.
Co-FounderGaida Zirkelbach
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Gaida Zirkelbach is Co-Founder of RunBrook and an entrepreneur with a background in company-building, business strategy, and law. She has helped build two companies across building performance and environmental data management.
Gaida co-founded and served as CEO of SustainaBase, a carbon accounting and sustainability data management software company designed to simplify environmental reporting and compliance. She helped take SustainaBase from concept to acquisition, growing it from an idea developed with her co-founder into a platform serving large publicly traded and private company customers. In 2024, she led SustainaBase through its acquisition by ISS-Corporate, a global leader in governance, sustainability, and risk solutions.
Before SustainaBase, Gaida helped establish RunBrook’s business foundation, playing a central role in the company’s early strategic positioning, brand, contracts, business systems, processes, and growth strategy.
Following the SustainaBase acquisition, Gaida has turned her focus back to RunBrook and the business side of growth: strengthening the company’s market position, improving financial discipline, solving complex problems, supporting scalable processes, and helping translate technical expertise into services that clients understand, trust, and need.
Before entrepreneurship, Gaida began her career as an attorney, later becoming a law firm partner and general counsel. Her legal and business background gives her a practical perspective on risk, negotiation, leadership, governance, and long-term enterprise value.
Gaida’s approach to business is grounded in the belief that a company can be both values-driven and commercially strong.