This project provides student housing for the College of the Atlantic (CoA) in Bar Harbor, ME.  The CoA is a small school with only one major: human ecology.  The school’s mission is not only to study our relationship with our environment, but also to improve it.

The new buildings will be accommodations for 51 students and are organized as "houses" of eight students, with six houses composing a residential cluster.

Finally, and critically for CoA, the new buildings are to be mightily resourceful producing their own energy, turning their waste into nutrients, and being healthy, invigorating places in which to live. Buildings today are likely to spend the bulk of their lives in a completely different resource climate- one based upon renewable energy. It is expected that these buildings will make a significant contribution to public education in anticipation of that eventuality.

A tightly constrained site, and a desire for clearly identifiable houses, suggested three-story buildings.  The prominent shoreline location and the intimate positioning of the buildings argued for diminishing an overly tall impression.  The upper level, therefore, is created as an attic story with a steep, (and lower) roof generously overhanging to increase the solar collection area, as well as providing a "rain hat" weather protection to the exterior wall.

The simple plan and building form allows for manipulation without additional complexity as the house modules are rotated, flipped, and turned to extract maximum potential from each of the six situations.  The simple module constrains cost and sets up a repetitive rhythm.

From a systems standpoint, the core driver was the College’s public goal to achieve campus-wide independence from fossil fuel by 2015.

This is a heating climate.  (With only 0.02% of the hours requiring cooling, air conditioning was unnecessary.)  The predominant strategy was, therefore, to minimize heat loss. 

Building enclosures were design detail constructed, repeatedly tested and verified to achieve a peak load of 8 BTU’s per hour/s.f. with R40+ walls, R45 roof plane, R5 windows, and a remarkable final air-tightness of 0.79 ACH50 consistent over three similar buildings. Without the comprehensive air sealing design and implementation the buildings would have been 7± times leakier.

In addition:

-    Simple roof geometries and large overhangs protect buildings in this wind-driven rainy environment.

-    Small rooms benefit from the single-story link, allowing windows on all sides of the upper stories.

-    Dramatically reduced heat load allows ventilation to provide the heating distribution to the upper two floors, thereby eliminating the considerably more expensive radiant floor initially planned.

-    No basements on this rocky Maine site.  Thermal mass coupling is fully preserved.

-    Entry air locks for each house preserve comfort in the small, populated living spaces.

Even with a zero fossil fuel imperative, we had system options. 

However, solar thermal opportunity was severely limited by tight site constraints, the client’s desire to retain trees, and a high year-round DHW load.  The dominance of the space heat, DHW loads, and the absence of an air conditioning requirement drove us past heat pump technologies. 

Site constraints pushed buildings together favoring a district heating solution.  The overarching requirement to relieve the existing buildings of their fossil-fuel dependence favored a boiler where the higher water temperature was better suited to the load profile. We chose a new product from Viessmann: a regionally sourced, biomass fueled, central boiler.

In addition:

-    Heat will be delivered at first floor level via radiant tubing in the concrete slab.

-    Drainwater heat recovery tied to showers helps pre-heat incoming DHW.

-    Roof planes are sized, cleared, and oriented as well as possible for future PV installation.

Partial Year Monitored Data (early 2009) suggests:

Total Annual Site Energy Usage: 44.70 Kbtu/sf/yr

We have tried many approaches to air sealing over the past twenty years, but we hit the jackpot with these buildings.  As noted earlier, the results were spectacular.  Here we adopted a deceptively simple procedure— taping the exterior sheathing, but with a tenacious self-adhesive tape over a contact adhesive primer on the OSB. We created a drawing in the plans - A5.2 Air Sealing -  to show the relevant details, in color.

Walls are double-framed 12”-thick and filled with dense packed cellulose insulation, a resourceful building material, which is particularly important here in preventing moist interior air reaching the cold exterior air barrier.  Insulation follows the 14” deep I-joisted, unvented roof planes.

Roof overhangs, which shelter the wall, are detailed for pre-fabrication and attachment after the primary air sealing is completed.

Coldham & Hartman Architects

Marc Rosenbaum, P.E., Energysmiths

E. L. Shea, Construction Manager

Phil LaClaire, Owner's Representative

Coplon Associates, Landscape Architect

Hedefine Engineering, Civil Engineering

Ryan S. Hellwig, PE, Structural Engineering

Petersen Engineering, Mechanical Engineers

Bartlett Design, Lighting and Electrical Engineer

 2009 Boston Society of Architects

Sustainable Design Award - Citation