This is the fifth of an open ended series of articles detailing the design and construction experiences of the Hensley Field Operations Center, a facility currently seeking LEED certification.

The USGBC North Texas Chapter is proud to announce that Hensley Field Operations Center has achieved LEED Gold certification. Hensley Field Operations Center, a vehicle maintenance center for the City of Dallas, is the first LEED certified facility in Dallas, and the eighth facility statewide to achieve LEED certification.

This major renovation of an existing 80,000 s.f. facility was begun in late 2003, and is housed at the former Dallas Naval Air Station. This property was recently reassumed by the City of Dallas, and is being converted into both public and private use. This vehicle maintenance facility supports several operations, most notably of which is the conversion of street vehicles into Compressed Natural Gas (CNG) vehicles for various City of Dallas departments.

Prior to design, Michael Kawecki, then Project Manager for the City of Dallas EBS/Design & Construction Division, decided that it was important to utilize sustainable design in this renovation. “The City of Dallas had recently adopted a green building resolution requiring that all new facilities over 10,000 s.f. achieve LEED silver certification. While this renovation was technically exempt, we still felt that it was very important to design within these guidelines where feasible. As an Owner of over 800 facilities, the City of Dallas is very aware of our impact on the built environment. It’s important to be sustainable responsible at every level,” Mr. Kawecki said.

“To be honest with you, it was quite overwhelming at first. This project had several important factors. Along with being our first design/build contract for our Division, it also had an extremely accelerated timeline, due to the closure of another facility for which this facility was the replacement. Add to that a very tight budget and lengthy contract processing times, LEED was only one of our concerns.”

“I knew that in order to make this happen, I needed a full team of professionals with varied expertise that I could rely on” Mr. Kawecki states. “We made a strategic decision to separately award professional LEED and Commissioning Services from the Design/Build contract. We wanted to be able to group the team by experience. By separating the contracts, we would be able to take advantage of the best of the best.”

Carter & Burgess/CMTS was contracted to provide LEED and Commissioning Services. Carter and Burgess already had a strong background in sustainable design, and with several LEED projects in the works, would be able to steer the design team in the right direction. Joining the Carter & Burgess team was CMTS, a full service commissioning firm. Together, this team would add expertise to the Design/Build team, and still be under direct contract to the Owner.

Kawecki remembers the initial design meetings. “As we started design, I was quite firm in my beliefs that we could achieve LEED Silver with no budget increase. Some of this was based on my past experience with sustainable design, but most was due to plain old stubbornness. I knew that sustainable construction did not significantly differ from our City standard construction practices – but eliminating that pre-conceived notion would be the first task at hand.”

“This is where Harrison, Walker, & Harper (HWH) came into the picture. We needed a design/builder that already subscribed to the principles of providing a value to the client through construction - not just simply constructing a facility per the prints. This distinction is clear, as they understood that the main goal was to give us a facility that would best suit our needs for the next 50 years.”

HWH has been building a diverse array of quality projects for more than 118 years. As the oldest construction company in Texas , HWH concentrates on design/build and construction management delivery methods, and specializes in building aviation, industrial, institutional, manufacturing, educational, commercial and medical facilities, as well as historic restoration projects. While new to the LEED process, they realized that LEED was just a method to quantify what they were already doing – and believed in!

Roger Bussell, HWH’s project manager, was apprehensive at first about the new guidelines required to obtain LEED certification. He said, “I thought it was going to cost more, take more time, and be difficult to get subcontractors to follow.” At the end of construction, Bussell admitted that the guidelines made the project run smoother. “We were so focused and so intense about following LEED guidelines that the project was more organized and consequently less difficult. As a LEED project, it wasn’t much different from our standard projects - just more deliberate about how we did things.”

Tommy Fulford, HWH’s environmental project manager, added, “The Hensley Field project was all about documentation and daily monitoring. It wasn’t difficult, but it wasn’t something that took care of itself.” Leonard Awtry, Project Superintendent, agreed. “The project demanded more attention to detail. Because it was something a little different, I thought of it as a challenge.” He continued, “I learned a lot, and I’m ready for the next one.”

Hensley Field Operations Center achieved 41 points under the LEED-NC v2.1 rating system, resulting in a certification level of Gold. When asked what the main factor contributing to the success of the project was, Kawecki had a simple answer. “Integrated design was the key to this project. By pairing the design team and the construction team together initially, and by having everyone contribute to the design early on allowed us to make changes on the fly in the design stage - and not in the field where changes can be costly in both time and money. At the same time, we had to break out of the mindset of ‘buying’ LEED credits. We focused on how the credits worked together and as a whole, rather than credit by credit. Before we knew it, we were well above our goal of Silver and into the Gold range.”

Some interesting facts about the facility:

• Utilizes highly efficient plumbing fixtures to reduce water usage by an estimated 50% over a conventional building.

• Utilizes highly efficient lighting fixtures and incorporates day lighting strategies to reduce electrical usage by an estimated 25% over a conventional building.

• Utilizes a photovoltaic (solar panel) array to offset electrical usage of the facility.

• Incorporates a roof-top cistern, which uses rainwater to irrigate interior plants instead of potable (treated) water. Also uses native landscaping across the site, eliminating the need for an irrigation system.

• Utilizes a geo-thermal well system for cooling and in order to reduce equipment sizes.

• Recycled/reused over 85% of the waste generated by construction.

• Almost 25% of all the construction materials used are made up of recycled content.

• Over 80% of the construction materials used were manufactured locally, and over 40% of those materials were extracted regionally.

• Reduced the potential for indoor air quality issues by utilizing construction materials with low-emitting VOC’s (Volatile Organic Compounds).