The new Waterline mixed-use complex is topping out at 74 stories, making it the tallest building in rapidly growing Austin, Texas, and the state. Its other landmark status is that it will be highly energy-efficient and qualified to achieve LEED Gold certification. Using sustainable piping for the plumbing projects was the key to accomplishing both goals.
The radiant heating and cooling system used PEX pipe, while the corrosion-resistant, hybrid hot and cold water plumbing system used both PEX and CPVC pipe. Due to the favorable environmental aspects and the overall benefits of using plastic pipe, the new structure was named the industry project of the year for the pipe supplier, GF Building Flow Solutions.
With a construction budget of $520 million, the Waterline has 2.7 million square feet, sectioned into 703,000 square feet for offices and 27,000 square feet of retail and restaurant space. It also features a five-star hotel with 252 rooms, plus 352 luxury residences. Designed by architecture firm Kohn Pedersen Fox, the structure aims to achieve LEED Gold certification with several sustainable features, including the use of the Austin Energy District Cooling System to provide chilled water to tenants.
While the design plan originally specified copper pipe for the domestic water system throughout the building, the change to PEX pipe for the residences on floors 41 to 74 provided savings in both materials and labor. The engineers also specified PEX for radiant heating and cooling in the lobby as a solution for energy-efficient comfort in a space with high ceilings.
Additionally, the project used CPVC pipe for the building’s mains, risers and mechanical room piping, providing a reliable hybrid solution that combines with PEX for a durable, sustainable system.
Installation costs cut by 20%
Waterline was named Project of the Year for 2024 by the Building & Construction Division of the Plastics Pipe Institute (PPI), the major North American trade association representing the plastic pipe industry. GF Building Flow Solutions (formerly Uponor in Apple Valley, Minnesota, and Uponor Ltd. in Canada), the pipe manufacturer and member company of PPI, received the award at the association’s annual meeting in May 2025.
“This was a massive undertaking with budget demands, tight construction schedules and sustainability requirements, which created a unique challenge for the building owners, engineers, designers, project managers and contractors,” explains Lance MacNevin, P. Eng., director of engineering for PPI’s Building & Construction Division.
The installing contractors, The Porter Co. (Manchaca, Texas) and MDS Maintenance (Austin), agreed that using flexible PEX pipe, which can easily bend to change direction, helped to reduce installation costs by nearly 20%, including labor.
Adding to that efficiency was the ASTM F1960 cold-expansion fitting system, which allowed their crews to make reliable connections quickly and easily. The cold-expansion fitting system eliminates dry-fitting concerns and provides greater jobsite safety because an open flame for soldering is not required.
According to GF Building Flow Solutions, by combining Uponor ChlorFIT Schedule 80 Corzan CPVC and Uponor AquaPEX, the hybrid system provides contractors with a product solution from a single source, under a single warranty.
As a schedule 80 pipe, ChlorFIT offers robust wall thickness and high pressure ratings, ensuring a long service life in riser and main piping applications. Matched with the flexibility of AquaPEX pipe, which is ideal for unit piping, the hybrid system delivers the best of both worlds: a perfect blend of flexibility, strength and corrosion resistance.
Radiant system maximizes efficiencies
For the radiant heating and cooling system in the hotel lobby, the flexible, durable PEX pipe provided consistent, reliable performance in a solution that maximizes efficiencies.
“Because water has the capacity to transport energy 3,500 times greater than air, hydronic radiant systems are far more efficient compared to traditional forced-air HVAC systems,” MacNevin explains. “Radiant cooling systems have the ability to absorb solar gain before it warms the air, increasing efficiency and comfort, and when heating, the pipe embedded in the floor delivers heat where people are located, providing greater comfort and efficiencies.”
The Porter Co. was also the installer for the radiant heating and cooling system in the hotel lobby and residences. This project used 1,841 feet of 1/2-inch to 1 1/2-inch diameter Wirsbo hePEX radiant barrier pipe, spaced 6 inches on center, for the seven loops in the design.
For the mains, risers and in the mechanical room, 2-inch to 8-inch diameter ChlorFIT CPVC was used. According to PPI, CPVC is a high-temperature plastic pressure piping used extensively in fire sprinkler systems as well as many industrial and process piping applications. It is approved in all model plumbing and mechanical codes across the United States and Canada.
Material kits increase installation efficiency
While product costs and reliability were important to the contractors, installation efficiency was at the forefront of their requirements to ensure alignment with the construction schedule and budget. They leveraged Uponor Kitting Services to help speed installation in the units while also minimizing jobsite waste, helping to promote sustainable building practices.
The customized, coordinated kits came complete with all essential ProPEX fittings, rings, transitions, valves, stub-outs, supports and other components in individual packages labeled by room. The kits also included a materials list, plan view and 3D isometric drawing for a clear installation plan along with scheduled delivery by level to streamline the project.
“As the tallest building in Texas at more than 1,000 feet,” MacNevin says, “Waterline is a perfect example to demonstrate the strength and reliability of plastic piping materials in commercial construction, even in super tall skyscrapers. With the completion of this project, engineers, contractors and building owners will have confidence to specify and install plastic piping systems in large commercial projects.”
Steve Cooper has reported on numerous plumbing, construction and infrastructure projects for several decades. Based in New York, he has traveled extensively to conduct on-site news interviews with professional engineers, contractors, government officials and representatives of major companies supplying the industry. He can be reached at 516/623-7615 or [email protected].
