Completion

Completion date
11/01/2008

Occupancy

Owner-occupied. Both owners are living in the house and both are away about 15 days per year. We have guests (1 to 4 at a time) with a usual stay of 2 to 4 days. Guests are present about 30 days per year. The ground floor with two bedrooms, full bath, family room, and kitchenette was designed for guests.

Days per year Building is fully occupied:
350

Scope

Trail Magic was built for Mary and Carl McDaniel, a retired couple, with the first floor and dormer being their living spaces. The ground floor was designed for guests with 2 bedrooms, full bath, family room, kitchenette, and a separate entrance from the south-facing, below-grade sun patio. Also on the ground floor are the mechanical and work rooms.

Type of Construction New
Number of buildings 1
Floor area of each building 2,494
Bedrooms 4
Bathrooms 2.5
Stories 2
Conditioned Building Volume 24,130 cu ft
Conditioned Floor Area 2,494 sq ft

Location and Climate Details

single-family residence

Address
495 E. College Street
Oberlin, OH 44074-1318
United States
Location Type Urban
Climate Region Zone 4
Köppen Climate Type Dfb
Lat. / Long. POINT (-82.1990961 41.2912854)
Elevation 778 ft
Solar Insolation 3.76 kWh/m2/day
Annual CDD and Base Temp 1090 | 65 deg F
Annual HDD and Base Temp 5339 | 65 deg F

Site

Site conditions:
previously developed land, lake/pond,, preexisting structure(s)
Site description:

Site is located in Oberlin, OH, about 1 mile from town center that had 2 derelict houses that were raised and 60% recycled. Rectangular lot of 4.7 acres with 235 feet on south side of College Street that extends 840 feet south with the southeast corner located in Plum Creek. The center of College Street is 22 feet above Plum Creek. The new house is positioned 100 feet south of College Street and 35 feet from the eastern boundary. A 0.2 acre pond was dug south of the house to provide fill to raise the house site about 6 feet above grade, to be a heat source/sink for a heat pump, to grow fish, and for aesthetics. About 3 acres are field including about an acre of tall grass prairie with the remainder in woods with about half being in the Plum Creek flood plain.

Materials and Design Strategy

Materials:

Local sources were sought and some recycled materials were used. For example: fill for raising house site ~6 feet came from digging a 0.2 acre, 12 feet deep pond; 16,759 board feet of site ash trees that would have been killed by the invasive emerald ash borer that had just arrived in Ohio and about a dozen other large trees were lumbered to provide flooring, shelves, book cases on stairwell wall, kitchen beam, front porch beams, pantry counter and shelves, closet shelves, dining table, and TV cart; recycled granite cobble stones were used for wood stove hearth; bathroom floor tiles were made from recycled material; front porch used recycled flag stones; and recycled stainless steel trays provided siding for wood bin in living room as well as the lining inside of a small ice box constructed under the counter in the ground floor kitchenette.

We elected to install a 24-gauge, standing-seam, metal roof instead of a standard shingle roof because it was made from ~75% recycled metal, would last for ~100 years with no or little maintenance, and could be recycled when removed despite the fact that the initial cost was 3 times that of asphalt shingles that would have to be replaced 3 times over ~100 years and the removed shingles would have to be put in a landfill. Prefinished, fiber-cement "Hardi-board" siding and trim were used for its durability, fire resistance, and low maintenance. High performance Loewen windows (triple pane on N, E, and W sides; double pane tuned for solar gain on S side) low-E argon with warm edge spacers were installed because of their exceptional quality and long life expectancy. Low volatile organic chemical paints were used on walls and ceiling, and water-based polyurethane on floors. Engineered rafters and joists were used in lieu of large dimensional lumber, which comes from old growth forests. Nothing larger than a 2 x 6 was used in construction.

Advanced framing techniques were used which minimized the amount of lumber needed without sacrificing structural integrity. Airtight construction of closed-cell spray foam along with extensive caulking and sealing, and high quality windows reduced significantly air infiltration (1.1 air exchanges at -50 Pascals). Insulation: under cement floor R = 20 (4 inches rigid insulation), ground floor half below ground with wall R = 35.5 (Reddi-Wall insulated concrete forms with additional 2.5 inches of wet-spray cellulose insulation, total thickness of 13 inches), first floor walls R = 47.5 (12 inch thick, double, 2 x 4 walls with 1 inch closed cell spray foam air barrier and 10 inches of wet-spray cellulose insulation), roof R = 62.5 (TJI rafters with 1 inch closed-cell spray foam air barrier and 15 inches of dense packed cellulose insulation).

Because of heavy clay soil that has zero percolation and in which garden vegetable plants grow poorly, we used grass mulch from our yard and fields as well as local tree chips and leaf-mulch soil to create organic soil for a 6,000 square foot garden. We acquired bare-rooted shrub and tree seedlings from Arbor Day donations and the local Soil and Water Conservation District to forest the front yard and reforest the flood plane areas from which we lumbered 16,759 board feet for the house and other projects.

We designed the landscape for water retention. A swale on the east side of the lot drains water away from the house through the tall grass prairie just east and south of the house and then down the meadow into the flood plane. A second swale on the west side of the lot drains water away from the house and from the garden into the pond. The pond is also fed by the overflow of a 1,850 gallon cistern that collects roof rainwater. We rehabilitated the flood plane area that had been a dumping ground for construction and other waste by removing or burying waste as well as by grading about half an acre to retain water before going into Plum Creek. We also planted tall grass prairie in 15 foot strips along the east and west sides of the garden, and a 10 foot strip around the pond. Tall grass prairie plants put roots down about 6 feet and some 65% of their photosynthetic product is put into roots thereby building soil water-retention capacity. The pond and tall grass prairie retain most or all of the water that falls on or flows into them.

Special architectural measures:

Trail Magic employs the following special architectural measures: 1) Passive design window placement with 2.5-foot roof overhang on south side (63% of glazing on south side that is 6% of floor area; window area in square feet: north = 47, east = 24, west = 19; south = 155; total glazing = 245). 2) Thermal shades on larger east and west side windows to block sunshine in summer and reduce heat loss on winter nights. 3) A window halfway up stairs from ground floor to first floor daylights the landing and stairs going from ground floor to first floor. 4) Open risers on stairs from first floor to second floor dormer daylight front entrance and hallway. 5) Four small windows in kitchen just above counter tops daylight counter tops. 6) Sunset windows are high on west wall to daylight kitchen and dining/living room at the end of the day. 7) A sunrise window is high on the east wall that daylights east side dormer study and 1st floor bedroom in the early morning. 8) An Internal window between west side of the dormer study and the dining/living room daylights dormer study and visually connects the two spaces. 9) Stairwell with open risers on second flight of stairs and ventilation windows at high and low points in the house were designed as a wind tower to provide a fully ventilated house in warmer months, especially at night when cool air is drawn into the house on the ground floor and exists out the dormer windows. 10) The ground floor provides a summer refuge that is naturally cooler due to the thermal mass and earth berming.

LCA Description:

Our overriding metric in design and material decisions was the life-cycle cost measured environmentally and economically with environmental aspects given the edge. This is well illustrated in our choice of roof material. Our sandstone colored (reflective index of 63), 24-gauge, raised-seam, metal roof for the house cost $17,000 while a 25 year asphalt shingle roof would have cost $5,500. The metal roof was made from ~75% recycled steel, should last ~100 years with little maintenance, and is recyclable when removed. An asphalt shingle roof is a petroleum product that must be land filled when removed, requires some maintenance, and must be replaced every 25 years or so. Based on the initial economic cost, the asphalt shingle roof is clearly the best choice. Based on life-cycle economic cost the choice is unclear because three replacements of the shingle roof make its total cost ($16,500) similar to that of a metal roof over 100 years. Environmentally the metal roof bests the shingle roof in current and life-cycle costs. Giving the edge to environmental considerations made the metal roof the best choice. Of course, over 100 years future owners benefit economically from this decision while we and the wider society benefit now and in the future from this choice. Deciding to design for passive solar was easy: it cost nothing extra, or very little, while the life-cycle environmental and economic benefits accrue immediately. We attempted to make this life-cycle analysis on major design and material choices; however, we were often lacking sufficient data to do justice to many decision.

Indoor Environment Description:
See "Special architectural measures" in section above. Equally important, we evolved in a world in which temperatures and light intensity gradually change in a daily cycle of highs and lows. Eons have honed our genes to prescribed physiologies acclimated to these changes and to daylight itself. Sunlight and temperature patterns of change are elements of our habitat -- where we would choose to live if we had a choice. Thermally and visually a passive solar house is a place of gradual change that enchants our senses that were honed long ago by evolutionary forces. In more than a poetic sense, we have come home when we inhabit a passive solar house. The indoor environment in a standard house is artificial, while in a well designed passive solar home like Trail Magic it is significantly less so and is conducive to health and feeling good.