About Us

Building projects don’t just happen overnight – they take months or even years of planning and execution.  That’s how we were built, too: over months and years, and project by project.  For 50 years now, we have been building on our engineering and land surveying expertise and developing a strong reputation while delivering seamless, dependable service to every project partner we’ve had.

While we’re large enough to provide an integrated array of services, we’re still small enough to be involved every step of the way.  When we approach a project, big or small, we are hands-on and thorough – in fact, a principal is involved with every project.  We’ve found that the collaboration that comes with forming a project partnership leads to  sound solutions, better projects and high trust with our project partners.

Our mix of project expertise, experience and people is unmatched.  We invite you to see what we can do for you and encourage you to contact us for more information.

Our Valuable Team Members

Ron Klaas, P.E.
Ron Klaas, P.E.President
Ron has more than 40 years experience in consulting engineering, land surveying and planning. He is President of D’Onofrio, Kottke & Associates. Ron brings his vast experience in the civil engineering and land surveying industries to help clients achieve the best possible solutions for their project. Whether it be a large commercial development, a residential neighborhood or small home site on the lake, Ron knows the ins and outs of how to accomplish the project on time and in budget. Ron graduated from the University of Wisconsin – Platteville with a degree in civil engineering and is a registered professional engineer in the State of Wisconsin.
Dan Day, P.E.
Dan Day, P.E.Principal Engineer
Dan came to D’Onofrio, Kottke & Associates in 1993 and has been involved in all phases of land development and public sector projects since that time. His experience in these areas has lead to him leading and being involved with many project teams during his career. Dan’s expertise is leading a project through its entitlement and design process and bringing it to fruition. He excels in the overseeing of project entitlement, project design, construction, scheduling and budgeting. Dan graduated from the University of Wisconsin – Platteville with a degree in civil engineering and is a registered professional engineer in the State of Wisconsin.
Bruce Hollar, P.E.
Bruce Hollar, P.E.Principal Engineer
Bruce has extensive experience in all aspects of public and private-sector civil engineering and land surveying since joining D’Onofrio, Kottke, and Associates in 1992. He has been responsible for design and construction administration on numerous public street rehabilitation projects, residential and commercial subdivisions, and individual commercial and multifamily sites. He is able to guide a project through all stages of planning, design, approval, and construction using an efficient and common-sense approach. Bruce graduated from the University of Wisconsin – Madison with a degree in Civil & Environmental Engineering and is a registered professional engineer in the State of Wisconsin.
Nathan Lockwood, P.E.
Nathan Lockwood, P.E.Principal Engineer
Nathan has over 18 years experience with D’Onofrio, Kottke & Associates. He is an expert in storm water management analysis and site design. He has been on numerous committees dealing with storm water management issues. Nathan also has vast experience in the design and construction of large commercial properties, residential and commercial subdivisions, and individual commercial and multifamily sites. Nathan graduated from the University of Wisconsin – Madison with a degree in biological systems engineering and is a registered professional engineer in the State of Wisconsin.
Brett T. Stoffregan, PLS
Brett T. Stoffregan, PLSPrincipal Professional Land Surveyor
Brett has over 15 years experience in land survey field. His talents of understanding new technology are necessary in today’s every changing world of technology. His experience includes completing certified surveys, subdivision plats, ALTA/ACSM land title surveys and plats of survey along with leading a field crew for many years. Brett graduated from Madison Area Technical College and with a degree in civil engineering technology and is a registered land surveyor in the State of Wisconsin.