We are proud to announce our new Principals and Associates for 2023. This group represents some of the best and brightest in our industry, bringing unparalleled value to the building science industry, our clients and partners, and their teams.

Please join us in congratulating this new generation of thought leaders in building science!


Lucas Nahrgang, P.E.

Principal, Senior Project Engineer

As Senior Project Engineer, Lucas Nahrgang brings nearly a decade of building enclosure experience and leadership to RDH’s Boston office. Starting as a Portland, OR co-op in 2013, Lucas eventually relocated to Boston and helped open our first East coast location. Alongside the region’s growing leadership, Lucas is helping to build a practice that establishes itself as the leading building enclosure consulting specialist in the region.

Lucas’ passion for historic buildings is present and palpable in his work where he strives to deliver highly technical, complex, and large-scale healthcare, life science, and higher-ed building enclosure consulting (BEC) and building enclosure commissioning (BECx) services to his clients daily. Lucas led the RDH team through building enclosure commissioning services, carrying out design reviews, submittal verifications, field observations, and testing, for the $512 million expansion of the Maine Medical Center.

Peder Hals, P.E.

Principal, Senior Project Engineer

Peder Hals is a Senior Project Engineer and licensed structural engineer in the RDH Boston office. He brings 14 years of building enclosure and project management experience in both new construction and existing building projects. Peder is passionate about building restoration and deep energy retrofits, recognizing the environmental benefit of reusing rather than rebuilding.

The technical lead for roofing and waterproofing services, Peder designed the new façade access equipment for Seaport Circle, a 650,000 sf life science and research building in Boston designed through a collaborative effort by Arrowstreet, Moody Nolan, and Studio ENÉE. Seaport is slated to receive LEED Platinum certification. Peder is former President of the New England Chapter of the International Concrete Repair Institute (ICRI) and is currently leading RDH’s practice development for the design and evaluation of facade access equipment.

Felix Weber, Dipl.-Ing. (Arch.), Dipl.-Ing. (Civil Eng.)

Principal, Façade Specialist

As a Façade Specialist in RDH’s Oakland office, Felix advances the delivery of complex façade and glass design for our architectural clients. He is a highly creative engineer and an experienced leader with over 16 years in façade consulting and structural engineering. Trained as a structural engineer and architect in Germany, Felix brings unparalleled experience navigating diverse cladding types, including long-span façades, structural and large-format glass, complex geometry, uncommon building materials, and innovative fabrication techniques.

Felix is the Façade Engineering Lead on the new hospital at UCSF Helen Diller Medical Center at Parnassus Heights (the project is being developed in a collaborative culture with a team of designers, builders, and the client through an Integrated Project Delivery [IPD] approach) with Herzog & de Meuron and HDR as Architects. He serves a critical role on highly visible, high-profile projects having elevated the design and delivery of over 250 structures internationally.

David Schnerch, Ph.D., P.E.

Principal, Building Science Specialist, and Structural Engineer

Dr. David Schnerch joins RDH in Boston as Principal, bringing over 20 years of consulting and research experience to the leadership team. His breadth of expertise includes condition assessments, structural evaluations, failure investigation, and repair designs for historic, existing, and newly constructed buildings. Dr. Schnerch’s experience allows him to provide practical solutions for building enclosure problems related to facades and facade components. He also performs peer reviews, pre-purchase inspections, capital reserve studies, and litigation consulting services for contractors, building owners, and other parties.

Dr. Schnerch led the building enclosure condition assessment of the Central Library in Boston during his time at WJE. He and his team assessed the remaining service life of the enclosure assemblies and prepared repair documents to improve performance and long-term durability. His research on ultra-high modulus fiber-reinforced polymer (FRP) materials for the repair of concrete and steel structures using ultra-high modulus fiber-reinforced polymer (FRP) materials are published in peer-reviewed journals. He is also the current Treasurer of the Structural Engineers Association of Massachusetts (SEAMASS) and was formerly the President of the Boston Association of Structural Engineers (BASE).

Harriet Tzou

Principal, Marketing Director

Harriet Tzou is a Marketing and Communications professional with 15 years of design, architecture, and engineering industry experience. She is passionate about using storytelling to create human connections, advance new ideas, and rethink what we believe to be possible.

At RDH, she leads the Corporate Communications Team. Focused this year on defining, expanding, and elevating the RDH brand voice through refreshed RFP/Q processes and standards, connected digital experiences, media partnerships, and system & operations—Harriet is creating a framework for marketing and communications at RDH to align growth strategies with capabilities.

She brings experience from SOM, Gensler, and her consulting work as well as fuseproject, a multidisciplinary design studio specializing in product, brand, digital, environmental design and strategy headquartered in San Francisco. Notable brands she has helped amplify and market include the circular-economy Forust 3D printed collection made of paper industry waste, The Ocean Cleanup Sunglasses made of plastic garbage retrieved from the Pacific Ocean, AI-powered FORME Life fitness system, and the 3D printed modular homes for New Story.

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