By now, our 8-year journey to energy independence has been documented with nearly 150 individual blog posts. For those who may be curious about our project but not enough to wade through myriad posts, perhaps the previous Part I and this Part II will suffice.
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Common Features
The windows are double-thickness with two kinds of glass – transparent on the first floor and translucent on the second
The transparent first story windows are backed up by thermal mass – the concrete floor and the soil beneath it. The solar gain through the windows warms whatever it shines on -- the floor primarily but also the furnishings which have minimal thermal mass but still contribute to warming the air. And, the medium shade for the floor hits the sweet spot -- a dark color would overheat and a light one would reflect, rather than absorb, solar energy.
second floor are not backed up by thermal mass and are more numerous than on the first floor requires a different strategy for maximizing solar gain during the winter. The glass in most of the second story windows is translucent (frosted). Unlike transparent glass through which sunlight enters uninterruptedly and heats whatever it shines on, translucent glass diffuses or scatters sunlight so that, in the absence of thermal mass, it heats the interior contents randomly and without overheating.
The most prevalent wall color in the house is rated at 65% reflectance which is the sweet spot between reflectance and glare. The reflective paint works in tandem with the translucent glass to scatter winter solar energy.
Our windows, in addition to
transparency vs. translucency, have
three additional energy-saving features – low-e coating, fiberglass frames and
swing design.
Low-e coating for a double-glazed window blocks up to 90% of the heat loss on winter
nights and cloudy days.
Fiberglass frames are “greener” than the more ubiquitous vinyl frames
Less embodied energy (made from sand rather than petroleum).
Co-efficient of thermal expansion matches window glass for better seal of double-glazing as well as minimizing air leakage between frame and glass; contrastingly, vinyl expands (summer) and contracts (winter) much more than window glass.
All windows are casement or awning (both swing style) that, on closure, create a compressible weather-proof seal. Sliding styles (double- or single-hung or side-by-side), need greater tolerances for sashes to slide freely within frames and, as such, have more potential for leakage.
Polished and stained concrete floors, in the absence of tile and carpeting, maximize the flow of heat from the mass in winter and into the mass in summer; in a few years, after the mass temperature reaches equilibrium, tile would probably work without compromising the thermal performance of the house.
Handicap accessibility, e.g., 36” doors with lever-type door “knobs", elevated wall receptacles, no grade changes between drive and house.
Combination fire and CO alarms for sleeping areas hardwired (with battery backup).
Numerous through-the-wall ventilators that allow stale air accumulating at the high point of the sloped ceiling of the first floor to escape to the second story.
Continuous ventilators at the top and bottom of the tall north wall, i.e., the one separating the living space and vertical basement, allow air to move back and forth through the wall and either deposit or extract heat from the thermal mass (concrete vertical basement wall and the earth behind it) depending on the season
Entryway
/ Kitchen / Laundry / Dining Room
Entryway wall veneered with
handmade bricks salvaged from 19th century farmhouse.
Salvaged kitchen and laundry cabinets
are Facebook Marketplace finds; laminate (Formica) countertops instead of
natural stone with its embodied energy (long distance importation or energy-intensive
manufacturing).
All appliances, range hood and ceiling fans are Energy Star rated.
Lowered countertop area that
doubles as lunch counter and ADA-compliant work surface.
Supply and return vents for ERV system.
Living
Room / TV Area
Continuous ventilators at
the top and bottom of the tall north wall (mentioned above).
Wall switches for all TV and computer receptacles to control phantom loads.
Guest
Bathroom
Salvaged wainscoting
for one wall
Porcelain tile for tub surround gifted by contractor (left overs from a job)
Recycled
ceramic (rather than fiberglass) bathtub (Craigslist)
Wash basin mounted on treadle-type sewing machine
Low-flow faucets and shower
1.2 GPF handicap height toilet
Exhaust
vent for ERV system
South
Bedroom
Energy Star ceiling
fan
Supply vent for ERV system
Master Bedroom / Walk-in Closet
Energy Star ceiling
fan
Supply
vent for ERV
Repurposed
closet organizer (Facebook Marketplace)
Master
Bath
1.2 GPF handicap height
toilet
Low flow faucets and shower
Exhaust vent for ERV
Recycled vanity with
manufactured stone countertop rescued from dealer’s “bone yard” (laminate is no
longer recommended for bathroom vanities)
Handicap accessibility
Wheelchair accessible shower with controls reachable before entering spray
25
sq ft of floor space in middle for
wheelchair turning
One sink is handicap
(and child) accessible
Numerous grab bars
Second
Floor Balcony (Catwalk)
Vents from first
floor to syphon off warm air accumulating at high side of cathedral ceiling.
Click-together composite floating
floor; composite is more sustainable than vinyl and, by being manufactured
from pulp wood, is even more sustainable than conventional hardwood flooring; medium color for a balance between absorption and reflection of solar energy.
“Green” windows
Translucent window glass vs.
transparent glass for better thermal performance in the absence of any
significant thermal mass on the second story
Windows inset 11” from
exterior wall plane to reduce heat loss due to “wind washing”
Only enough operable windows for adequate ventilation (fixed windows have a much higher Energy Star rating than identical windows that are operable)
Second
Floor Bedroom / Bathroom
ERV supply vent (bedroom) and return vent (bathroom)
Corrugated roofing for
bathroom wall cladding (long-lasting and recyclable end life)
Recycled
wall cabinet (Habistore)
1.2 GPF
toilet
Unfinished
projects
Custom stairway and railing
system from rough sawmill lumber:
stair steps from hackberry; balusters from hackberry and red oak,
railings from red oak
Interior casework (baseboards, trim
around doors and windows, etc.) from rough sawmill red oak
Once the interior is finished, a certified consultant using a blower door tester will ascertain the tightness of the house – a major criterion for either a HERS rating (Home Energy Rating System) or NAHB rating (National Association of Home Builders) that we will seek.
ACKNOWLEDGMENT
We will be forever indebted to the government of Collinsville, IL, particularly the Building Director and his staff for their forbearance during nearly a decade of construction. If the folks at city hall had not taken genuine “ownership” for the town's first "green" project, it would never have been built.
RECOGNITION
At Collinsville's 2022 Awards Night, the local chapter of the Cool Cities Committee recognized our project with its "Cool Cities Sustainability Award". (The nationwide network of Cool Cities Committees was birthed by the Sierra Club. As ambassadors for sustainability, the club's members serve as advisors to the City Council as well as to civic committees, schools, organizations and citizens.)
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