Friday, June 8, 2012

A Home Both Beautiful and Sustainable by Melinda Barnhardt


John Muir said it best. "Everybody needs beauty as well as bread" (The Yosemite, 1912). Too often sustainability trumps aesthetics; yet one Virginia couple was determined to make the home they would design and build both green and beautiful. Remarkably, throughout their project, the two goals proved complementary - and in the built design, a unified vision.

MEF Logo 742
Collage by Michael Ayers of Ayers, Inc., Lima, OH
(Click the image to view larger)

Background:
The husband and wife had distinctly different visions for the wooded property they had purchased. He wanted a house that was energy-efficient and passive solar; she wanted a home that was aesthetically pleasing, and Mediterranean or Persian in character. What were the chances of realizing their desires within a single dwelling - and one that they would build themselves, with their own hands?

Design Concept: The design would capture heat from the sun (via a long, windowed southern exposure) and store it in a thermal mass comprised of masonry floors and an eight-inch thick internal masonry wall. A modularized plan would allow for zoned heating and cooling. Shed roofs opening on the south side would mean additional sun capture. The house's configuration - four modules with a stepped footprint on the south side - would provide east facing windows for morning sunlight. As an added benefit, the "step" between the kitchen and living room modules would allow for a Mediterranean style patio.

Highlights of the Built Design:

Foundation: The house's position on a slope allows for windows in the above-ground portion of the basement, making basement living space viable. Since basement rooms (with supporting walls) were defined during the design phase, the need for unattractive center posts was eliminated. The external walls of all basement rooms (with the exception of the furnace room) are covered with six-inch fiberglass insulation next to the block walls, and then sealed with plastic to minimize air leaks. The insulation allowed for putting up drywall, a nod to future décor and beauty.

Frame: Six-inch thick stick frame construction allowed for six inches of insulation in the external walls. The insulation is sealed with plastic, as in the basement. (Note: The "tight house" has an air exchange capability.)

Exterior: Synthetic stucco with a one-inch foam base enhances the insulating effect. (There's no problem with synthetic stucco, assuming use of expanding rubber tape to seal the intersection between windows and the stucco.) The buff-colored stucco conveys a Mediterranean look - particularly, when topped off by a terracotta-colored corrugated steel roof with baked enamel finish (and an economical fifty-year guarantee). Likewise suitable for a Virginia barn, the roof blends with its rural surroundings.

Interior: An eight-inch thick concrete block wall forms one side of a gallery hallway opposite the south-facing windows on both the "basement" and main floor levels. The concrete-filled block wall (with mortar finish) provides thermal storage, retaining heat from the sun for use at night. The dark green color of the wall (on the first floor) absorbs heat nearly as well as black, and simultaneously conveys a Persian garden motif: a column of leaf-and-vine design tile running up the living room end of the block wall serves as its interface with the living room's white drywall. Windows high up on the block wall provide natural lighting for the guest bath and guest bedroom interiors.

Floors throughout the entry hall, kitchen, living room, and gallery hallway are heat-absorbing 2 ½-inch tile and mortar. The terracotta pink tile (Mexican volcanic rock) is low-maintenance, and reinforces the Mediterranean/Persian garden motif. Non-vitreous and relatively warm (think bare feet in winter), it also withstands below-freezing temperatures. Thus its use is continued on the south-facing patio and a north-facing courtyard, creating a bond with the outdoors.

In keeping with the Mediterranean aesthetic, windows throughout the house are deep-set, as result of the six-inch framing. Walls in the entry hall and dining room are covered with thick- textured paint, giving the effect of masonry.

A seasonal benefit of the design is that the thermal mass and thick walls moderate temperature changes. The high summer sun is prevented from heating up the internal thermal mass (block wall and masonry floors) by surrounding deciduous trees (approximately 25 feet from the house).

How he got more of what he wanted: Two geothermal heat pumps, one at each end of the house, provide zoned, energy-efficient heating and cooling. When no-cost firewood is available, a damper adjustment allows changing over to a wood-burning furnace in place of the heat pump for the dining room-kitchen and living room modules. When in use, the wood-burning furnace also preheats the supply water for the hot water heater. A "hot water heat pump" mounted on the electrical (resistive heating) water tank extracts heat from the surrounding air to heat the water at half the cost of resistive heating.

How she got more of what she wanted: Seen from the front entry, two Mediterranean style archways provide a framed glimpse of the kitchen. (Note: these have nothing to do with energy efficiency!) An 1100-piece Persian design latticework serves as divider between the entry and the dining room. Across the hall from the lattice, at the entrance to the living room, is a six- foot wide pocket door. Comprised of a less complex lattice mounted on either side of a sheet of translucent white acrylic (picture a shoji screen with a Persian design.), the door is illuminated like a lantern when the living room is lit at night.

Moral of the story: A mindfully designed house can be both green and aesthetically appealing!

The Bottom Line: Cost for the six-acre lot, a two-car garage, and 3229 square feet of living space was $260K plus $32K for the two geothermal heat pumps and wells. Costs include excavation and foundation, HVAC, insulation, and drywall, carried out by others.

1 comment:

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