The Bosarge Family Educational Center at the Coastal Maine Botanical Gardens

Project Subtitle: 

Maclay Architects

Project Description: 

The Bosarge Family Education Center at the Coastal Maine Botanical Gardens was designed through a collaboration between our firm, and a local Maine architecture firm, Scott Simons Architects.

The client wanted to construct a new education center adjacent to their existing visitor’s center to serve as a model of sustainable, energy-efficient design. From the outset, the client outlined strict environmental guidelines with the goal of a LEED-Platinum, net-zero, beautiful building blending into the context of the surrounding gardens. The building was also to be an active teaching tool by outwardly demonstrating energy and resource conservation to visitors.  

This net-zero building is designed around a central open gallery: a gateway to the gardens. Two wings extend from this central core into the landscape, one housing administrative functions and the other flexible public space. Extensive glass enhances the connection to nature for occupants.

 The pre-determined site was a confined parcel adjacent to an existing visitor’s center. Located in a valley, this site presented a challenge to the design team of maximizing the solar access critical to net-zero performance.  In addition, the client wanted to preserve as many of the large coniferous trees as possible. The site, along visitor’s central circulation path, allows the staff to be connected to the arrivals and departures of guests.

The orientation of the building allows for the use of passive solar strategies, optimizes the orientation of the roof-mounted PV and solar hot-water panels, and minimizes the impact to the existing site and trees.   Meters provide real-time energy data for all systems. Signage and a “truth wall” educate visitors about the buildings sustainable features. The highly insulated building envelope, high levels of daylight, and automatic controls optimize occupant comfort.

The client set forth a strict schedule for the project in order to preserve the experience of visitors during the high summer season. To meet this tight schedule a panelized construction system was used which allowed for off-site fabrication, minimized on-site waste, site impact and time. This project is the first net-zero project by our office completed utilizing a panelized system, and through careful thought and construction, it meets the air infiltration standards required for net-zero buildings. The panelized process offers a level of control and precision in a factory environment.  The envelope design and building assembly now established within the prefabrication parameters can be adapted for other projects.

The building design brings to life the mantra, “If a plant designed a building…”

Building Type Summary: 

Education Center and Botanical Gardens

Address: 

132 Botanical Gardens Dr.
Boothbay, ME 04537
United States

Elevation: 

60

Lat. / Long.: 

POINT (-69.6590196 43.8761026)

Location Type: 

Rural

Köppen Climate Type: 

Dfb

Climate Region: 

Zone 6

Solar Insolation: 

4.52 kWh/m2/day

Occupancy Type and Details: 

The Bosarge Family Education Center is occupied by office personnel full-time during working hours and is often used by visitors and for larger group activities on the weekends and evenings, especially during the summer season. The office staff in the building comprises 10-20 people depending on seasonal occupancy and daily needs. Events in the space are common and include 20-200 people. Therefore, occupancy is assumed at a higher number than just office staff.

≈ 300 Days of Occupancy
≈ 9,000 Person Days of Occupancy

Conditioned Floor Area: 

8 200

Multiple buildings?: 

Historic?: 

Power Rating: 

45Watts

Electric Utility Company: 

Central Maine Power

Electricity amount (imported from grid): 

24 320

Electricity amount (credited or exported to grid): 

32 286

Net electricity usage (purchased electricity): 

-7 966

Subslab assembly: 

4” EPS rigid insulation

Slab edge assembly: 

4” EPS rigid insulation

Foundation wall assembly: 

4” EPS rigid insulation

Above grade wall assembly: 

Dense pack cellulose in 11–7/8” I-stud cavity

Flat attic assembly: 

Dense pack cellulose in 16” I-stud cavity

Space heating - Manufacturer & Model: 

Mitsubishi

Space cooling - Manufacturer & Model: 

Mitsubishi

Domestic hot water - Manufacturer & Model: 

Solar domestic hot water

Ventilation - Manufacturer & Model: 

ERV

Total Cost of Project: 

3 200 000

NESEA Awards: 

2013 Zero Net Energy Building Award

Energy Use and Production Documentation: 

Subslab R-value: 

20.00

Slab edge R-value: 

20.00

Foundation wall R-value: 

20.00

Above grade wall R-value: 

40.00

Flat attic R-value: 

60.00

Average window U-factor: 

0.16

Solar Heat Gain Coefficient: 

0.20

Visible Light Transmittance: 

0.60

Door U-Factor: 

0.42

Cost per square foot of Conditioned Space: 

390.00

Window Description: 

a. Windows: Low-e, tri-pane, argon filled, FSC certified
i. 0.16 U-value, 0.24-0.16 SHGC, 0.57-0.629 VLT
b. Skylights (Type 1) 16 mm nanogel-filled polycarbonate inner layer
i. 0.154 U-value maximum
c. Skylights (Type 2) Triple-glazed, low-E2, argon filled, 0.27 U-value

Door Description: 

Exterior doors, Low-E2, tri-pane, argon filled, 0.42 U-value

Status: 

Live

Weight: 

0