“Abacus pays great attention to detail. They provide the level of detail and service that you get from the big companies, but with fewer layers of management and less hoops to jump through. You get to work directly with the owner – and Chas always wants to do a great project. For him, the architecture matters, and he’s very willing to work with us to make the end product right.”

Ted Bonneau, Architect
OXB Studio, Mill Valley


“The greatest strength of Chas, his ability to listen, contributes to all aspects of working with Abacus. He is comfortable with compromise and always offers multiple solutions. The team of subcontractors and suppliers are highly knowledgeable about their craft and are always respectful and mindful of the client. The idea of reaching for excellence informs all decisions with Abacus. I have thoroughly enjoyed our working relationship and highly recommend both Chas and Abacus.”

Laurie Ghielmetti, Interior Designer
Laurie Ghielmetti Interiors, San Francisco


“As a structural engineer, I work with a lot of general contractors with varying skillsets. Abacus is at the top of my list because of their unusual understanding of engineering requirements and their creativity in helping me achieve them. In addition, they have great craftsmanship, professionalism, integrity, and tenacity. They don’t shy away from challenges, they make the difficult look easy, and they do it with grace. And they are very nice people and a pleasure to work with.”

Ryan Billante, PE and Principal
BKG Structural Engineers, San Carlos


“The Abacus team understands the importance of planning, so they are great at budgeting and anticipating, as well as at building. Chas likes to look farther down the road, considering what your future needs might be. When you do improvements, you build them into the value of the property—and Chas totally gets that.”

Scott Haskins, President
Sierra Maestra Properties, San Francisco 


“Abacus appreciates that visual comfort is so much more than just what you see. So much is possible if you plan ahead—and if you work with a contractor who sees the client and the designer as partners in the entire process. Chas likes to collaborate conceptually on how the project can enhance the client’s life, from increasing storage capacity to improving energy efficiency—to installing an elevator.”

Timmie Friend, T.
T Friend Interiors, San Francisco


“The Abacus ethos isn’t about hammering nails. They really enjoy the connection between everyone: the architect, the designer, the contractor, the sub-contractors. They are totally focused on doing the whole thing together.”

Dave Hindley, whose family lives in a home completely built by Abacus