Not every property comes complete with its own vintage carriage house ready to be converted into a garage, office or living space. That’s why the owner of a 1920s house in Kensington, Calif., a small community just north of Berkeley in the East Bay Hills, sought out Keith Alward, president of Berkeley-based Alward Construction to create a free-standing structure with modern functionality, yet with more than a nod to the grace and classic design of the home it complements.
The resulting structure pays homage to John Hudson Thomas, a California architect credited with a number of Berkeley-area landmarks. He practiced in the early 1900s and has been associated with the Arts and Crafts movement though by most accounts the homes he designed were progressive, eclectic and defied simple categorization. They often combined elements of California Bungalow, Prairie, Mission and other styles of the era.
The owner didn’t want just a garage but rather an amalgamation of functions in a coherent and tasteful architectural package that offered office space, which might later be used as guest quarters or living space and additional parking. It would mirror the architecture of the John Hudson Thomas home and—a big challenge—not detract from an adjacent outdoor amphitheater where the homeowner, who is a retired music industry executive, often stages fund-raising concerts for charitable causes.
Windowed Stair Tower
A dramatic feature of the design is a windowed stair tower that overlooks the amphitheater. Because the original house has true divided-lite windows, Alward wanted to replicate that look in the carriage house. Present-day codes, however, require dual glazing. To accommodate this requirement, a window system was designed with muntins close enough in size to the original to be acceptable, yet strong enough to carry the weight of a large number of individual dual-glazed lites.
The custom-made window required its own foundation, framing and special installation because the weight of the large stepped window was significant. To make its installation possible, the dual-glazed panes were installed after the window frame was in place.
“Constructing a window of this type while meeting the size requirements was challenging in terms of providing a window that would properly shed water,” Alward says. “The windows were designed to result in a continuous window sill that travels the full perimeter of the tower, even as it steps down.”
The tower was constructed of tubular steel, which provided strength with minimal width. However, this yielded an additional challenge for creating a waterproof system that could be clad in stucco to match the rest of the structure.
“The stair tower itself is all steel; there’s no wood construction except around the steel. It was a bit of a challenge to fit this system together so that it really looked like old-time construction with stucco and wood,” Alward says.
Not only does the divided-lite appearance of the windows complement the architecture of the main house, the step-down of the stair-tower windows also mirrors a design motif from the structure, which has a window that steps down along the vertical lines of the muntins.
“The windows in the house only step down two panes, where the stair-tower window goes down quite a number of panes,” Alward adds. “It’s a very complex window system.”
The site offered several challenges, but Alward is modest about them. “There was some work on siting that was a little complicated but manageable,” he says.
“The biggest issues of the site were to accommodate requirements in terms of distances from trees and property lines. It was a bit of a struggle to locate [the new structure] precisely,” he adds.
There were no specific historic restrictions, but “Contra Costa County, which is the governing agent, was very specific about what the structure could and could not be and its size, location and setbacks,” Alward says.
Construction required cutting into an existing retaining wall and, because the structure is built on a hillside overlooking the amphitheater, concrete piers were required to stabilize the foundation. Managing trucks making deliveries up the narrow driveway also required patience and planning.
The second level of the carriage house, currently outfitted as an office, has cathedral ceilings and large exposed-beam trusses. Partition walls with arched penetrations define spaces, which include a kitchen and space that is currently configured as an office for an assistant. The main space is designed as an office but could easily be a living room should the owner’s needs and the function of the carriage house change. A full bathroom is located on the lower level.
One side of the office/living room features an operable glass wall system that provides a large unobstructed opening to a deck overlooking the amphitheater. The gable ends of the space feature divided-lite windows, and skylights provide additional light. After the sun has set, a sophisticated lighting scheme conceived by a lighting designer shows off the architectural details of the carriage house. The lighted stair tower is a dramatic presence above the amphitheater.
“There was a lot of attention paid to the lighting design,” Alward says. “It was pretty carefully thought out.”
Likewise, a great deal of thought was given to details in the living/office space, including casework for built-in bookcases and inlaid patterns that have personal significance to the owner in the hardwood floor. Detailing also is evident in the stair tower and elsewhere. “We custom made the mouldings, so if you went from the existing house to the interior of the carriage house, it would look very similar,” Alward relates.
Exterior Fine Points
Outside, knee braces were cut with a band saw from large timbers to replicate those on the original house, and hand-carved details were added. “We don’t get a lot of jobs where we can get out wood-carving chisels and go to work,” Alward says.
The attention to detail extended to the stucco applied to the carriage house. The original home had pebbles embedded in the stucco to give it a unique texture, and the owner wanted to match that look. Descriptions of John Hudson Thomas’ work note that he was a master of combining materials on his exteriors.
“It’s the first time I’ve even seen a house with that kind of texture in stucco,” Alward explains.
“We did not have access to the material the original builder used,” he adds, “but we did find a substitute that is almost indistinguishable from it. During the final coat, the pebbles had to be pressed into the wet stucco by hand. I was worried about it from the beginning, but we pulled it off.”
Alward’s crew also rebuilt the stage of the amphitheater, which was suffering from dry rot, and installed exterior rails along paths leading to the back door of the carriage house. A substantial landscaping effort also was part of the project though Alward was not involved in that phase of the work.
“This was a great project for us,” Alward says. “We were very honored to have the opportunity. It’s a special looking building that really complements an existing structure and fits into the site in a lovely way.”