The greenest building is the one already there… but it sure uses a lot of energy!
As architects, we are well attuned to the fact the buildings account for nearly half of all energy use. As we rehabilitate existing buildings, we reap the benefit of the “embodied energy” in the materials and existing construction— key factors in life-cycle energy use. We augment the performance of the existing structure with insulation, air barriers and thermal breaks where ever possible. Historic buildings provide an added challenge; to maintain character defining features, we are limited on what surfaces can be covered, and to what thickness.
At Atlantic Design Works we used a few of our favorite tricks to ensure this historic structure wouldn’t continue to be an energy hog:
High density continuous insulation provides more heat resistance per inch of thickness and eliminates thermal bridging when compared to typical fiberglass insulation between joists or studs
High efficiency condensing furnaces & electric heat pumps. While these need to connected to drains, and may have more technical requirements, you often save the floor space (on each story) of needed a large chimney or flue to vent them.
Two solar panel arrays on roof were sized respectively to offset 50% of the rotunda’s total energy demand (including 100% of its electricity) all while keeping a low profile and roof-edge offsets for historic and fire code standards.
