Controlling Main Street costs with tilt-up construction

Bradburn’s first commercial buildings — two 11,000 sq. ft., one-story retail structures — face one another at the primary entrance to the development. As such, they must enclose the street and make a strong impression on visitors. The original design called for three-story, mixed-use buildings incorporating a retail first floor with offices and residential units above. The upper floors were eliminated due to a post-9/11 office market collapse and a study of apartment rents in the region which showed that rates were not high enough to justify the expense of a second story. The challenge became how to create a sense of place and make an architectural statement with a single story while keeping costs down. The solution was to make tall single-story shopfronts, 24 feet at their highest point. The facades will also enable Continuum to transition to two- and three-story buildings planned later for the town center, when it becomes more established. Tilt-up construction is a method of building the exterior wall horizontally and raising it up relatively rapidly in large units with a crane. This method, often used for commercial buildings and warehouses in the West and Southeast, involves pouring a concrete floor and using it as a casting slab. Workers then lay out brick patterns and make openings for door ways, windows, and utility pipes, then fill in the rest with concrete. The savings from this method helped keep costs down and enabled Continuum to afford architectural accents. Continuum wanted a mix of traditional and contemporary elements. The building caps step up and down like those of a Main Street in a frontier town. They are all brick, with modern metal details and stained concrete pilasters. The thin brick is patterned to lend interest to some of the larger wall sections. Free-span roof framing joists eliminate interior columns (the added expense for the joists is canceled out by the savings from the lack of columns, and the end result is more flexible commercial space). Sustainable design features include a white reflective roof and a building shell that performs above the standards of the American Society of Heating, Refrigeration, and Air Conditioning Engineers energy efficiency code. Much attention was given to the exterior pedestrian scale and how a shopper will experience the building while walking along the street. Clear storefront glass, blade signs, and recessed entry features are used along the street frontage, and building materials were chosen for their “touch-and-feel” characteristics. Four-sided architecture was required due to the adjacent Main Street, rear entries, and paseos connecting the rear parking lots and front entrances. Large sidewalks were built to accommodate outdoor dining. A ten-inch-diameter steel tube along each facade provides a place to mount two front signs for each tenant and incorporates lighting.