LAWA'I, Kaua'i — From the outside, the building under construction at the National Tropical Botanical Garden looks little different from any other — but its design and construction are particularly appropriate for an institution whose mission is conservation.

It stands among towering eucalyptus, pink and red-blossomed erythrina trees and rare palms from around the world, and will overlook the garden's main office complex as well as the sweeping landscape of lower Lawa'i Valley, where the organization's McBryde and Allerton gardens are.

The garden's new two-story Botanical Research Center building, besides being built to withstand a 150-mph hurricane, is part of a new wave in the Hawai'i construction industry — structures designed and built so they make as small an impact as possible on the Earth and its resources.

The Botanical Research Center will seek a classification that only a few buildings in Hawai'i have achieved, but which could become a standard: certification by LEED, the Leadership in Energy and Environmental Design of the U.S. Green Building Council. LEED is emerging as the nation's premier rating system for environmentally sensitive building.

Among Hawai'i buildings already built to LEED standards are the Case Middle School at Punahou School, the John A. Burns School of Medicine in Kaka'ako, the Gateway Energy Center at Natural Energy Laboratory of Hawai'i and Maui's Dowling Co. headquarters.

The garden's Botanical Research Center will be the first major LEED-certified project on Kaua'i. The contractor, Unlimited Construction Services, is using it to gain experience and to train subcontractors in the new techniques involved.

"We do government buildings," said Unlimited president Peter Robson. "I thought that it would be a good avenue to learn everything possible about this system, being economically and environmentally sensitive. We're finding we can do both."

NTBG President Chipper Wichman said a lot of folks get confused when they hear about the project.

"Most people when they hear we're building a green building at a garden, they think we're building a greenhouse," he said.

When the garden set out to build a home for the Loy McCandless Marks Botanical Library, for which it is caretaker, as well as to provide it with needed researcher office space, a home for its herbarium and an educational facility, it went through a painful design period in which many design alternatives were studied and then scrapped.

"We went through a number of architects, and the board could never settle on one design," he said. Eventually, they met with Honolulu architect Dean Saka-moto and began looking into the most environmentally friendly construction and design process possible. LEED came up quickly.

"It's a holistic way of looking at construction and minimizing your impact on the environment," he said.

The two-story design that evolved has poured concrete walls and massive concrete two-story pillars, with tree-like limbs at the top to hold up a concrete roof. Inside spaces are open, except for the most valuable books in the library, which will be in a special, climate-controlled room to protect hundreds of antique botanical texts.

Once the garden had a design, it needed to find a builder at a time when Kaua'i's construction industry was so busy most builders wouldn't even bid on the project. Robson at Unlimited made room in his firm's schedule, in part because he recognizes that experience with LEED will be a selling point for the builder.

"It's a new paradigm in construction," Wichman said.

Robson assigned project manager Todd Lang, an engineer, to the project.

"It's been a learning process," Lang said. But he finds that LEED is a logical advance in construction. "If you pay attention to detail, it's not that much of a burden."

The crews buying reinforcing iron must check to ensure their steel contains as much recycled metal as possible. Some of the lumber is recycled from buildings that have been torn down. Excess concrete is broken up and reused as roadbed material. Scrap metal is sent to a recycler. Plastics are recycled.

Wichman and Lang said they are frustrated that they have not found a good way to recycle termite-treated lumber, which unlike untreated lumber, can't be ground up and used as mulch on the garden premises.

Lang said he's proud that of the 750 cubic yards of waste that has been hauled from the site, 700 yards went to recyclers, and only 50 yards to the landfill.

Some of the building's parking areas will be covered with a porous grid made of recycled plastic, which will allow rainfall to percolate into the soil instead of running off. An underground water tank stores rainwater captured from the roof, and the water will be used to irrigate plants downhill from the building site.

The design has wide overhangs to shade the walls, minimizing heat transfer inside. The air-cooling plant uses an energy-efficient system.

All paint, glues and carpeting are vetted to ensure there are no toxic fumes that could compromise indoor air quality. Affixed to the roof will be a 29.9-kilowatt solar photovoltaic array.

"This project touches on every aspect of construction, but (green building) is just being more conscious of everything throughout the process," Lang said.

Reach Jan TenBruggencate at jant@honoluluadvertiser.com.