William Maclay - Vermont Architects and Planners
Choices in Sustainability
Coastal Maine Botanical Gardens - Boothbay, ME


The Coastal Maine Botanical Gardens wanted to construct a new educational center adjacent to their existing visitor’s center to house both administrative office space as well as flexible and adaptable classroom space that could also be used for various events and gatherings. The building needed to establish a strong connection to the outdoors and the neighboring botanical gardens. The client also set out strict environmental guidelines from the beginning of the project, requiring the building to have minimal energy loads and be both LEED Platinum certified and net-zero.


Many high-performance building strategies were incorporated into the design in order to achieve the net-zero goal. The building’s super-insulated envelope features R-20 below ground insulation, R-40 above ground walls, an R-60 roof and R-5.5 windows. A panelized wall system constructed off-site reduced waste and minimized site disturbance. On site 90% of construction waste was recycled. Locally harvested, FSC certified wood was used extensively. The building is sited to take advantage of ample southern light. Natural daylighting, along with energy efficient fixtures reduce lighting loads by 60%. Rainwater collection and high-efficiency fixtures reduce water demand by 75%. Operable windows open to provide natural cooling and ventilation.

A variable volume refrigerant heat pump system provides both heating and cooling. This air-to-air heat pump extracts heat from the outside air in the winter and rejects heat to the outdoors in the summer. Energy recovery ventilators provide fresh air while recovering about 70% of the heat from exhaust air. A solar domestic hot water system reduces energy demand, while a 45 kW rooftop mounted photovoltaic system provides clean, on-site energy.

The building is intended to be a teaching tool for visitors to communicate the importance of resource and energy conservation. Meters on display in the building provide real-time data for indoor and outdoor lighting, water use, electricity production and mechanical systems.

This energy data is also available for viewing online:

Building Dashboard 1
Building Dashboard 2

Visit the in the news page for articles on the recent grand opening or read about it here in the spring 2014 High Perfomring Buildings newsletter.

Also visit YouTube for grand opening footage:

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