Allegheny College, a national liberal arts college where 1,600 students with unique combinations of interests, skills and talents excel, celebrated its bicentennial in 2015. A leader in sustainability, the college achieved carbon neutrality in 2020. Through the Better Buildings Challenge, Allegheny College committed to reduce energy consumption 20% by 2020 in 1.3 million square feet of building space across their campus. Progress has been made through a combination of building efficiency retrofits, building management and behavior change, sustainable construction and renovations, and strategic divestment of properties to remove inefficient properties and increase density of usage in others. Carr Hall, a LEED Gold renovation, houses the Richard J. Cook Center for Environmental Science and is showcased under the Better Buildings Challenge program. The renovation includes high-efficiency HVAC systems, daylighting and efficient lighting solutions, as well as glazing, shading, and a vestibule to increase the lobby's energy efficiency. Bentley Hall, of which the cornerstone was laid in 1820, was recently sustainably renovated with envelope improvements, geothermal heating and cooling, controls, and LED lighting.