August 4, 2017. ENR California announced its Best Projects Award winners for 2017. The Sufism Reoriented Sanctuary in Walnut Creek, CA was honored with the Award of Merit in the Cultural/Worship category.
Decades in the making, the sanctuary for Sufism Reoriented in Walnut Creek, California will serve as the principal center of worship for centuries to come. Sufism Reoriented’s spiritual leader, Murshida Conner, approached world-renowned architect Philip Johnson and his firm Philip Johnson-Alan Ritchie Architects for the sanctuary’s design. Together, they developed a concept of sinuous circular elements to reflect the principles of unity, inclusiveness and longevity. The result of their collaboration is a structue designed to last 700 years – an articulated cluster of one-story, marble-clad concrete domes.
To lessen its impact on the residential neighborhood, two-thirds of the building is tucked below grade and topped with a green roof garden. The largest dome is 78’ across and covers a column-free Prayer Hall and a symbol of unity inlaid in its floor. The central dome is surrounded by four 38’ diameter domes and eight smaller domes. The entire structure, including the large central dome and medium domes, are constructed of concrete cast on site and the smaller domes are precast glass-fiber reinforced concrete. The 66,074 SF project includes within its rotunda and prayer hall a 20’ diameter oculus with skylight. One of the medium domes features a 38’ tall bronze sculpture reaching up from the lower level to the skylight above. Approximately two thirds of the building is located below grade where the congregation has offices, classrooms, a kitchen, gallery, art storage and music studios to support their art and cultural programs for centuries. Contemplative gardens surround and top the structure on the three-acre site. Soga + Associates was the architect of record and Thornton Tomasetti served as structural engineer. Overaa Construction was brought in to provide preconstruction and specialized concrete construction services.
Built to Last 700 Years
Sufism Reoriented wanted a physical manifestation of the core principals of their faith, including the important principal of longevity. When the Owner expressed a desire for a structure that would last not decades, but seven centuries, the concept was hard for the building team to initially accept: it would mean designing and constructing a building above and beyond code compliance. Soon, however, the team realized the Owner was serious – the building was to endure centuries – and they embraced the formidable task. As the project came to life, the team frequently commented that they were proud to be part of something that would endure beyond their lifespan. Sufism Reoriented built the structure using talent from within the congregation. Overaa worked to supplement and coordinate many in-house artists who contributed to the project. For example, the stunning 38’ tall bronze sculpture was designed by a congregation member. Along the gallery walls on the Concourse level are murals depicting the central tenants of Sufism Reoriented, created by Sufism Reoriented artists.
In a departure from contract-driven relationships, Overaa acted as construction adviser and community member as much as being a general contractor and specialized concrete expert. Overaa began with a comprehensive preconstruction effort that lasted more than four years. They led the Building Information Modeling and scheduling efforts for the structure, and brought design-build MEPF and other key trade partners in early to coordinate the building systems within the interstitial space. They partnered with Sufism Reoriented to see the project through to completion from digging in the ground to the final strokes of paint and plaster on the walls. It takes a village to build a project. In addition to its own crews and specialists performing the structural concrete work, Overaa collaborated with specialists from Largo Concrete, Dees-Hennessey, Dolan Concrete, ACCO Systems, Morrow Meadows, Diablo Plumbing, Westech Roofing, Carone & Co., Bayside Interiors, Cleveland Marble, and many others to make this project successful.
The world-renowned international structural engineering firm, Thornton Tomasetti, was called in to collaborate with Overaa to develop a poured in place, steel reinforced concrete building that far exceeded all requirements for longevity and endurance. The high seismicity of the site represented additional challenges in coming up with a design that would last 700 years. While the California Building Code aims to protect life safety of occupants, Sufism Reoriented pursued an approach that would minimize damage to the building during a seismic event. The building was designed using an R-factor of 1.25, rather than the R-factor of 5 which is typical for special reinforced concrete bearing walls. According to Thornton Tomasetti, this approach reduces the ductility demands on the structure and aims to keep seismic forces in the elastic range of reinforced concrete. Additionally, special reinforced curvilinear concrete shear walls serve as the lateral system for the above grade portion of the sanctuary. These 12 drum walls act as both shear walls and beams spanning between the basement columns. Even the congregation’s 38’ bronze sculpture is designed to endure seismic activity: it sits on four triple friction pendulum base isolators.
The building is innovative through and through – there is a state of the art 4-projector, surround sound speaker Audio-visual system in the main prayer hall that envelopes the congregation with sound (speakers are hidden within the columns.) Projected images can be seen from any position around the rotunda. Landscaping and mounding outside the project further aid in blending the structure into its residential surrounding. It is evidence of smart planning and carefully conceived and constructed details to minimize its impact on the community.
Formwork for the domes consisted of closely spaced radial ribs of dimensional lumber, cut to curves and spliced together. Thin plywood forms were cut in wedge shapes and then were bent to form the curve and then fastened to the ribs. The concrete ring beams at top and bottom were placed first in order to insure that they, rather than the formwork, would bare the hoop stresses resulting from the wet concrete. During construction, Overaa placed 13,000 CY of concrete and used a robotic total station to achieve strict tolerances. Concrete for the mat foundation slab was required to reach 4000 psi compressive strength at 56 days. This longer-than-usual time period allowed for the use of less Portland cement – just 282 pounds per cubic yard and an equal amount of Class F fly ash – to create a more environmentally friendly mixture that would last longer than traditional cement-only based mixes.
The interior spaces also required a high level of precision. Walls are all to a level 5 finish to accept art and murals. Trim, installed by Overaa craftsmen, is as much as 24” tall and crown moulding follows the curves of the cylinder walls. Light inside the building is mostly indirect. Gold leaf adorns the rotunda and prayer hall perimeter, as well as the underside of the main skylight and oculus. Downstairs is a full commercial kitchen downstairs and individual marble clad stalls in the restrooms where fixtures are covered in gold leaf.
The core principals of Sufism Reoriented have shaped the design of its new sanctuary:
The circle expresses eternity, because it has no beginning and no end. It also expresses unity, since all points on the circle are equidistant from the center, just as all beings are in relation to God.
The Color White
The white color symbolizes purity, unity and inclusiveness because white is produced when all of the colors of the rainbow are blended together. White represents the belief in essential oneness while recognizing the existence of wide diversity of life.
Creating a Light Footprint
The building is nestled in a quiet neighborhood. Its design reflects Sufism Reoriented’s goal to tread lightly on the earth. The sanctuary’s ground level walls are curvilinear, significantly reducing the visual impact of the building from every direction; the building literally recedes from view. The majority of the building is subterranean to lighten its presence and lessen its impact. A green roof and garden over the ground floor slab and outside the footprint of the above-grade story features contemplative gardens with pathways meandering around the building.
Light and Sound
The main feature of the ground level is the large central dome, 78 feet in diameter. Its 20 foot diameter skylight oculus bathes the Prayer hall in natural light. An inner “Spitz Dome” was created by the same firm that created the dome for the San Francisco Planetarium at Golden Gate Park. This inner dome is made of thin, finely perforated metal that allows sound to pass through to acoustical material behind it, providing an acoustical treatment that lessens reverberation while celebrating the unique sound qualities of a dome.