A 38-metre-high treehouse by American studio Mithun is the venue for the Jamboree of the Boy Scouts of America, but also functions as a treetop exhibition centre for visitors to the surrounding West Virginia park.

The Sustainability Treehouse is located at the Summit Bechtel Scout Reserve, a 4,000-hectare tract of land in rural West Virginia. It was designed by Mithun as the permanent home for the two-week-long Jamboree, which takes place every four years and is attended by 50,000 scouts and volunteers.

The architects specified unfinished materials that would naturally weather, reducing the need for maintenance. These included Corten steel, reclaimed oak and locally sourced black locust, which was used for siding and floors.

The building was designed to be self sufficient, so sustainability initiatives were introduced to enable it to generate its own heating, electricity and water.

Photovoltaic panels and wind turbines are fixed to the roof, while a 4,500-litre cistern and water cleansing system allows occupants to reuse rainwater and a composting toilet system helps to reduce the water demand.

A steel staircase leads up through the four main storeys of the structure, which alternate between indoor and outdoor spaces. Exhibitions on each floor teach visitors about sustainability, whilst immersing them into the forest canopy.

"The treehouse captures the wonder of childhood exploration and places environmental education at the forefront of meaningful experiences and camp messages for thousands of annual visitors to take home," said Mithun.

As well as the annual scout Jamboree, the structure plays host to annual festivities and educational programmes throughout the year, and forms a meeting place at the heart of numerous woodland activities.

The Sustainability Treehouse was one of ten buildings recognised by the American Institute of Architects (AIA) as the top green projects of 2014 and was praised by judges for its "exuberant and expressive design" that is both "contextual and respectful of the site".

"The project introduces sustainability in a playful manner by getting boy scout campers up into the trees in order to explore the forest canopy and to learn in the living classrooms," said the judges. "The project makes sustainable building techniques easily accessible and understandable."

Photography is by Joe Fletcher.

Read on for a brief project description from Mithun:

Sustainability Treehouse

The Sustainability Treehouse, a Living Building Challenge targeted interpretive and gathering facility situated in the forest at the Summit Bechtel Reserve, serves as a unique icon of camp adventure, environmental stewardship and innovative building design. Mithun led the integrated design process and a multidisciplinary team to achieve the engaging, high-performance facility.

The Treehouse provides dynamic educational and gathering spaces for exploring and understanding the site and ecosystem at the levels of ground, tree canopy, and sky. The towering Corten steel frame elevates visitors to extraordinary vantages and provides an armature for green building systems, such as photovoltaic panels, wind turbines, and a large cistern and water cleansing system. Interactive exhibits showcase and celebrate sustainable technologies. Overall, the treehouse captures the wonder of childhood exploration and places environmental education at the forefront of meaningful experiences and camp messages for thousands of annual visitors to take home.

Design Architect: Mithun
Executive Architect/Architect of Record: BNIM
Exhibit Design: Volume, Inc./Studio Terpeluk