Court Adjourned

After nearly 100 years of operation, the Herman Marion Sweatt Travis County Courthouse, constructed in 1931 in Austin, Texas, was in dire need of replacement after falling into disrepair. The building was unable to support the growth of its constituents.

To replace the aging courthouse, Travis County formed a public-private partnership (P3) as a design-build project to construct the Travis County Civil and Family Courts Facility. The new courthouse is a 12-story, 448,000-sf structure located in downtown Austin and includes 25 courtrooms, with a single level below-grade garage. The adjacent plaza is comprised of five levels of below-grade parking topped with a green roof. Design of the structure began in the summer of 2018 and the project was completed in December 2022. The project has received an Austin Energy Green Building 4 Star Rating (out of 5 stars maximum) and a LEED Gold designation.

From the onset, the new courthouse site had a bevy of challenges. For example, there is a 12-foot grade differential from west to east. Therefore, the new courthouse rests on a podium that spans the length of the entire block it occupies.

The lower level occupies the podium immediately beneath the building and includes the secured parking area for judges, the MEP rooms as well as additional building support. The west half of the podium below the plaza includes the five levels of below-grade public parking. The green roof above the public parking garage features a landscaped public plaza with elevator banks to service the parking below. More importantly, this portion of the podium was also designed to serve as the structural support for a future 14-story office building.

Another challenge to the design and construction of the facility was adhering to the fast-track schedule, which included achieving the building permit and accurate guaranteed maximum price with minimum contingencies within nine months.

The development team closed an alley, condemned a holdout parcel, rezoned the site, and achieved the site permit with an extraordinarily complex utility in less than nine months through its partnership with the county. In addition, the team managed approximately $6 million in savings from contingency and incorporated scope changes needed by the county beyond the design criteria through the savings with minimum disruption to the schedule, according to Rodney Moss, senior vice president at Hunt Companies.

In concert with Martinez Moore Engineers, Walter P Moore provided structural engineering design for the Travis County Civil and Family Courts Facility. The firm also provided secure design services that included vehicle barrier and site securing consulting.

Specifications were prepared for fixed and operable barriers rated for vehicle impact. One challenge related to secure design was the provision of K4-rated operable wedge barriers located on an elevated level, so the structural floor system was designed to support forces developed under vehicle impact.

This barrier system was located on a split slab, in order to waterproof the occupied space below grade, which required a close examination to provide adequate support without excessive depth. To achieve this, a 14-inch-thick elevated concrete slab acted as the base for a 6-inch-thick topping slab, set on top of a drainage layer, which was doweled into surrounding beam at the perimeter. The wedge barrier was then anchored to the 6-inch slab.

Multiple aspects of a design-build project occurring concurrently is not surprising, and the Travis County Civil and Family Courts Facility was no exception. The foundation for the tower was being poured at the same time the five-story parking garage was being excavated. To ensure both were constructed safely and efficiently, tiebacks were used as the retention system during the excavation of the foundation. Careful coordination was critical during the foundation excavation of both the tower and the garage as the tiebacks and the tower foundations had to be placed precisely to ensure there were no conflicts between the two.

Furthermore, communication amongst all the building team members was key because the tiebacks were extended below the roadway as there were below grade utilities that could not be disrupted. This was achieved through meetings with the Austin Utility Coordination Committee, to ensure there was no conflict between the utilities and the tiebacks. Within the site, the tiebacks for the garage extend under the building’s concrete foundation to ensure there was not a conflict, according to Ash Bajaj, project manager at Hensel Phelps.

The Travis County Civil and Family Courts Facility is primarily a concrete structure with precast concrete panel façade walls. The structure is supported by drilled piers that are set at a depth of 18 feet below grade and extend into the stiff Austin Group Limestone below. The piers located adjacent to the sub-grade parking garage were drilled even deeper, up to 40 feet, so as to not impact or interfere with the supports for the garage which were over 45 feet below the basement level of the courthouse.

A mat and pier caps that support shear wall banks were placed as part of the foundation in order to support the main elevator bank as well as the service elevator. The shear walls operate as a lateral support system for the structure. Additionally, the basement walls for the tower’s single-story garage are integral to the support of the complex framing, including all of the planters and stairs, at the first floor.

Because some of the courtrooms needed unobstructed space, a pan formed beam system with post-tensioned girders was used throughout the structure. This provided an opportunity to design bays that measured up to 40×45-feet. The 25-inch deep, 7-inch-wide pan formed beams were typically spaced at 53 inches clear and spanned up to 40 feet to reach 25 feet deep, 42-inch-wide post-tensioned girders.

The five-story below-grade parking garage required a large amount of excavation before construction could commence. The piers in the garage were drilled much shallower, only 8 feet, in comparison to those used for the courthouse building due to the deep excavation into the rock. The lateral system utilized for the garage is a combined moment frame and shear wall system with the ability to add additional shear walls through the basement levels for when the 14-story building is eventually constructed. Form savers were added to the several columns as well as sleeves in the slabs that would allow for the future walls to be added.

In order to reduce restraint, the basement was detailed so that it is only tied into the perimeter walls at the middle bay in each direction. This method required the columns to be offset from the basement walls and then the perimeter beam framing utilized bond breakers except at the tied in bays. Typically, there is a 5-in. slab on pan forms below grade, but the depth of the slab was increased to 6-1/4 in. with deeper pans underneath the first floor of the garage due to the extensive landscaped areas as well as the loading bays.

One thing that further complicated circumstances for the garage were the slab slopes required to drain water underneath the landscaping. Ultimately, Gensler developed a landscape model in Revit in order to provide the accuracy required for both design and construction.

The green roof on top of the garage includes a small pavilion at one end with a stage on one side and elevators and staircases for the garage on the opposite side. Several planters and trees are located throughout the greenspace. The greenspace is open to the public and is accessible from three different sides of the property. Staggered every two levels in the tower, secure terraces with greenery and outdoor seating provide a soothing environment in which to decompress, according to Luis Santi-Merayo, principal and design director at Gensler.

This facility boasts a unique feature wherein it offers access to the outdoors from the waiting areas past security. However, it is also the site where joyful events take place such as adoptions and weddings. The facility aligns very well with the spirit of Austin and blends nicely with the skyline. The site encourages community engagement, featuring spacious sidewalks, pedestrian benches, bike racks, and a public community plaza, all easily accessible by foot, bus, and bike.

The interior design of the courthouse includes a large main entry that has a monumental steel staircase offset a two-story stone clad wall in the main lobby. A vibration analysis was conducted on the stair using an imported forcing function in SAP to ensure all comfort and strength requirements, as outlined in AISC Design Guide 11, were met. The stair design was further complicated by the shared structural support framing with the nearby stone wall, which required deflections to remain under L/600. Besides the lobby, the stone clad walls are also present throughout the building, including the courtrooms, providing a cohesive, elevated design that was not limited to the main entrance.

The design of the Travis County Civil and Family Courts Facility was approached with a hospitality mindset that include light-filled, airy interiors and multiple outdoor spaces. The overall design evokes a sense of calm for visitors, many of whom are involved in stressful situations.

Overall, the facility exceeded the county’s vision both in terms of scope and delivery method. The delivery method allowed the county to make cost effective decisions throughout the process. This included a fully dual piped reclaim water system to substantial enhancements, designing the structure and systems for a future adjacent building, and changing building technology to enhance building security and enable remote trials and hearings, and minimize building occupancy.

The result is a building that adds energy and dynamism to the streetscape and presents itself as an approachable facility.