Case Study: Houston Texans Stadium

Words: Nick G and MASONRY Magazine
Photos: BrianScantlebury, Art Wager

They say that everything is bigger in Texas, and NRG Stadium, the home field of the NFL’s Houston Texans, certainly lives up to that claim. Built in a scant 30 months at the beginning of the 21st century, it is the largest stadium in the National Football League and shattered multiple records for construction when it opened for business in August of 2002.

The Idea

The city of Houston was already famous for one stadium before the Texans came to town. In 1965, the city opened the Astrodome, the first domed stadium anywhere in the world. It served as the home base for the NFL’s Houston Oilers and Major League Baseball’s Houston Astros for several decades until it fell out of favor due to a glut of new sports stadiums opening across the country that were more fan-friendly and featured executive suites that their owners could see at high-dollar value every time there was a home game. After a series of mishaps in the mid-1990s, the Oilers left Houston in 1996 and relocated to Nashville, Tennessee. Fearful the Astros would do the same, the city built Minute Maid Park, a gorgeous downtown stadium with a retractable roof that opened in 2000. Within a year of the Oilers leaving, a new group of businessmen, led by local billionaire Bob McNair, was lobbying the NFL to award Houston a new team. Beating out a bid from Los Angeles, McNair and company won the franchise rights in October of 1999 at a cost of $700 million. With the team slated to start playing less than three years later in 2002, the new owners had little time to lose.

The Master Plan

The stadium wasn’t just going to be the home of a football team but also a new site for the Houston Livestock Show and Rodeo, an annual two-week event that kicked off every February and drew massive crowds with a combination of carnival rides, food, competitive events, and music concerts by the biggest names in the industry. Early on, the idea was floated to give the structure a retractable roof, something no other NFL stadium had. The team hired a pair of local architectural firms - Hermes Architects and Lockwood Andrews Newman - to form Houston Stadium Consultants. 

Plans were made for it to be the largest stadium in the NFL, with the most seats and the most luxury boxes. The design was for a 1.9 million square foot edifice with a price tag of $360 million.  

The Engineer of Record for the project was Walter P. Moore, who had worked on multiple other massive projects in Texas, including the Bank of America Tower in Houston. 

The Construction Process

The stadium’s designers envisioned using kinetic architecture - that is, a plan where parts of the building can move without the structural integrity suffering overall. 

Precasting was done by Heldenfels Enterprises Inc., overseen by The Consulting Engineers Group Inc. of Texas. The contract job was awarded to a joint venture between Manhattan and BEERS. The precast concrete was integral to the project’s success. Heldenfels Enterprises Inc. fabricated a staggering 1,944 riser sections, 148 raker beams, 80 slabs, 122 stair units, and 369 wall panels. With the NFL breathing down the franchise’s neck to have the stadium completed for a national television debut in September 2002, all of those pieces had to be erected in a 10-month period.

The Consulting Engineers Group of Houston used three-dimensional drafting techniques to plan out the details of how several of the pieces would sit in line with the super columns that provided the support for the main part of the stadium.

Using a three-dimensional model before production began in earnest, they were able to not only visualize the pieces but actually erect and connect them before doing it on the real thing.

The columns were cast-in-place concrete with different measurements in all three planes, requiring precise fits to achieve the necessary results.

The crowning achievement was the roof, the first of its kind in the NFL. The roof used a sophisticated computer system to open and close on 206-meter-long trusses holding the rails. The roof separated at the 50-yard line of the field and could open or shut completely in just seven minutes.

What crowds at the popular franchise’s stadium don’t typically see are the 800,000 lightweight 8”x8”x16” concrete masonry units (CMUs) that strengthen its walls. Each block is loaded with rotary-kiln lightweight aggregates, giving it the elusive combination of strength without being so heavy that they become a burden on the structure. 

Reduced weight in a structure as large as NRG Stadium might not seem like a big deal, but for the Texas environment and the Texans’ ownership, it is a welcome relief. The lighter CMU means lower construction costs for the supporting beams and rebar to hold them in place. It also means less construction equipment is used for a shorter amount of time to put them into place.

The CMUs were constructed by Camarata Masonry Systems, famous for its work on athletic builds in Texas. Camarata has also designed football stadiums at the University of Houston and Texas A&M University, along with the Houston Astros’ Minute Maid Park and the Houston Dynamo’s BBVA Compass Stadium.

Overcoming Houston’s chaotic weather, the stadium was completely finished in time for the 2002 preseason. On September 8, 2002, the Texans officially opened NFL play on national TV, defeating their in-state rivals, the Dallas Cowboys. 

Renovations

Despite being built to withstand hurricane-force winds, NRG stadium suffered significant damage at the hands of Hurricane Ike, which hit Houston in September of 2008. While there was no structural damage due to the masonry components, both the roof and parts of the stadium’s interior were damaged. The cost was $11 million, and Harris County sued the custom roof manufacturer - Birdair Inc., for the roof’s failure to live up to its promised strength. The lawsuit was settled out of court, and the stadium’s repairs were completed five months later.

Looking Back

The gamble by the Texans and the City of Houston to build something the likes of which the world had never seen has been a tremendous economic and branding boon for both organizations. The stadium has hosted two Super Bowls - in 2003 and 2017; three NCAA men’s Final Four tournaments - in 2011, 2016, and 2023; massive concerts for worldwide famous artists including The Rolling Stones, One Direction, and Taylor Swift; and has shattered attendance records for the Houston Rodeo year after year. Since NRG Stadium opened, nine other NFL teams have built retractable roof stadiums, proving how innovative the original was.

References
https://www.chron.com/news/houston-texas/article/County-sues-over-Ike-damage-to-Reliant-roof-1711629.php
https://www.khou.com/article/sports/reliant-roof-repairs-nearing-completion/285-34297442230728_EAE_reliant.web.qxd (aisc.org)
https://www.cegengineers.com/projects/nrg-stadium-nfl-houston-texans/
https://www.aisc.org/globalassets/modern-steel/archives/2004/04/2004v04_reliant.pdf
http://stadiumdb.com/stadiums/usa/reliant_stadium
https://arcosalightweight.com/case-studies/lightweight-cmu/nrg-stadium
https://www.camaratamasonry.com/arena