Principal

Katharine has more than 20 years of experience in high-end residential design, both on her own and working for others. Her extensive background in art history and fine art brings an added level of artistry and sophistication to her work.

Jeff founded the design firm Charles Street Design (CSD) in 2000 and became a Principal of LDa when CSD joined LDa in 2024. His personal style has evolved into an eclectic combination of period style with modern forms, and he expects all design elements to have purposeful connection, achieved with texture, form, and color.

Erin’s strengths lie in her ability to create exceptional experiences that capture a client’s brand, goals, and aspirations, while incorporating proven space planning concepts, innovative uses of materials and technologies, and a clear design vision. Prior to joining LDa, she spent a decade immersed in restaurant and hospitality design for some of the region’s most notable venues, bringing together developers, owners, investors and specialty consultants to coordinate an effective and cost-saving design process.

Doug is one of LDa’s cofounders, and his design experience and leadership have been invaluable to the growth of the firm. Doug’s wide range of experience includes residential work, primary & secondary schools, universities, and a variety of not-for-profit organizations. His passion for environmental preservation began long before the existence of LEED and was a major focus of his undergraduate studies. Since then, Doug has maintained his commitment to protect the environment and address the issues of climate change through his design of numerous sustainable projects.  

Treff is one of LDa’s cofounders and has achieved local and national recognition for his expertise in the merging of historic and contemporary aspects of New England residential and institutional architecture. His professional experience has focused on providing client-focused and context sensitive design and project management services. Treff is a creative leader in a collaborative search for appropriate design solutions and has designed multiple residences to LEED certifications.