About 30,000 square feet was added to the Paul Thiry-designed landmark church at the top of Island Crest Way on Mercer Island. The addition includes multipurpose space for classrooms, administrative offices, kitchen and dining areas, and an enlarged sanctuary.

The project was originally conceived as a steel structure with a light-gauge metal stud and stucco exterior envelope. When the project emerged out of the schematic design phase, it was significantly over budget.

To save costs, Crownover Construction suggested using a combination of concrete tilt-up walls and site-cast precast concrete column and beam elements for the primary building structure. The project was then reworked with the architect and structural engineer to shave $200,000 off the cost of the original plan.

Using concrete instead of steel also simplified and solved several design and constructability issues. For example, by reducing the number of component parts that make up the building’s exterior envelope to one — concrete — the detailing and execution of the interfaces to other materials like window systems and door frames was much simpler.

Concrete also allowed the contractor to simplify the project’s task sequencing and quality control because of the reduced number of trades and related equipment needed for the work. For example, no scaffolding was needed around the perimeter of the building because no sheathing and stucco were installed. That allowed the building to be dried-in more quickly and for site improvements such as sidewalks, paving and landscaping to be completed weeks earlier.