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[ambient sounds of the neighborhood]
>>Lou: "First of all, I want to welcome you all. I'm Lou Host-Jablonski.
I'm an architect; I work at Design Coalition. Today, I'm a... I'm a homeowner as well,
and I'm welcoming you to my home." [continues talking]
>>Narrator: 30 Lansing Street in Madison,
Wisconsin is being constructed as a research and demonstration project, with the goal of
integrating green building practices into a conventional urban setting.
The wood-efficient structural system is modeled
on the National Association of Home Builders "Optimum Valued-Engineered Framing".
>>Lou: "The structure is a very simple 2 x 6 structure, 24 inch on-center studs..."
>>Narrator: The structural loads -- floor joists
and roof trusses -- all bear directly over the wall studs.
>>Lou: "...up there" [continues talking]
>>Narrator: One minor alteration is "letting-in"
one of the top plates. It gains us some extra insulation value,
and functions as a window header too.
>>Lou: "..you put the windows between
the studs, and you use this as a header, you get a very simple framing system, that's
very quick. You use quite a bit less wood..."
>>Narrator: By sizing the windows to install
between the studs, we avoid large old-growth
headers and all the extra framing around the openings. This home used about
one-third less wood than if it were conventionally framed.
>>Narrator: Straw-clay walls are the heart of this integrated building system.
>>Lou: "The art of straw-clay, as we're discovering,
is to put as little clay in it as possible, to make it the highest percentage of straw.
The clay has some real advantages, in terms of moisture, in terms of cohesiveness
of the wall and so on. So in this climate, where you want a thick, well-insulating wall,
you use as little clay as you can get away with."
>>Bill: "It's nice and coated; all the straws
are nice and brown. So you just bring out a bunch like this, and you twist it
a little bit, and you *** it together, and if it keeps its form..." [continues talking]
>>Narrator: Earth and straw mixed have been
used as a building material for millennia. There are 400 to 800 year old straw-clay
structures in Germany and Japan that are still in service today.
Straw-clay is a non-loadbearing, infill material.
Properly mixed and detailed, straw-clay with natural plasters is a durable, energy-efficient,
mold & mildew resistant, low-impact and non-toxic wall system. [sounds of construction]
>>Lou: "We're using this clay, from this place in Wisconsin, for our base layers.
For our final coats, where we are...where we need finer control, we do have the
dried bagged clay." [sound of mixer and talking]
>>Narrator: This project has afforded us the
opportunity to master the art - and advance the science - of earth-based plastering.
Our plasters are mixes of sand, clays,
lime putty and chopped straw fibers.
>>Bill: "So we'll add that last...we'll add this last."
>>Narrator: Small quantities of added casein
- which is a milk protein - and linseed oil significantly improve weathering
and moisture penetration properties.
Our recipes vary, for scratch coat, browncoat or finish coat [people talking]
and whether for interior or exterior. [sound of the plaster sprayer]
>>Narrator: Roof overhangs are extremely important for the longevity of the home.
Generous overhangs protect walls and windows from sun and rain
and can greatly reduce maintenance and water problems. And carefully sized overhangs
on the South-facing walls allow solar heat to reach the windows in winter,
but shade them in the summer. They are an integral part of the home's passive
solar heating -- and natural cooling -- systems.
A Midwestern home can save a significant percentage of its heating bill
by using the sun's energy. Passive solar design is a cost-effective way to do this.
A passive solar house needs three things:
First, a good, high-performance thermal envelope -- its walls, windows and doors,
and good roof insulation;
Second, the correct size of windows and house orientation to the sun; and,
Third, thermal mass for storing heat. The
thermal mass of this house is in the floor.
The slab, soil cement in our case, is supported by rows of bricks or concrete blocks.
The design is called an "air-core" floor because room air, heated by the sun,
circulates under the slab.
Here's how the passive solar cycle works: The sun enters the south-facing windows, heating
the floor and air. A blower circulates warmed room air under the slab to store the heat.
At night, the insulating shutters are closed and the stored heat rises into the room.
In summer the cycle is reversed to keep the house cool naturally.
Sun and heat are excluded with overhangs and shutters. Cool night air
flushes out the house, and the thermal mass stores the "cool" for the next day.
>>Lou: "...so you want to vary the exposure a little bit as you go...it looks a lot better..." [continues talking]
>>Narrator: These shingles are 100% recycled; one-half ground-up wood pallets and one-half
waste plastics. They include UV stabilizers and come with a 50 year warranty.
In the exterior walls, the electrical wiring is conventional nonmetallic sheathed wiring, type UF.
It's stapled tight to the framing
to avoid damage when the walls are packed with straw-clay. [Lou talking to participants]
Scrap plywood extenders bring the boxes to the interior.
To help minimize exposure to stray voltage
and electromagnetic fields, we use flexible MC-type wiring for circuits within 6 feet
of sleeping areas.
>>Narrator: The interior doors and many other elements in the house are reused or recycled.
But the windows are new, because the the performance of the windows is crucial
to overall energy conservation. The north-facing units are triple-glazed
and all of the windows include low-emissivity coatings.
>>Lou: "This is the heat for the entire house, plus the heat for the hot water,
all in this little unit, the size of a suitcase..." [continues talking]\
>>Narrator: This unit is a Quietside boiler
burns natural gas at 90% efficiency, similar to the most efficient furnaces, and
much better than conventional water heaters. The onboard computer gives priority to
domestic hot water heating over the space heating.
This is one of the few heating units available
that will operate efficiently at the very low heat-loss rates
that are typical of small, well-insulated homes.
Heat is delivered to different zones in the house via radiant ceiling tubes, refurbished
cast iron baseboards, and through tubes embedded in the slab floor.
>>Narrator: Winters in Wisconsin are cold,
and if you're going to build a home warm and free of drafts, you must build
a very tight envelope. Yet good ventilation is needed to prevent the indoor air
from becoming stale and unhealthy.
The answer is an energy recovery ventilator - an ERV. These simple units consist of
a box with two fans and a special "core" element inside.
This ReNewAire unit is made in Wisconsin. The ERV uses the stale outgoing warm air
to heat the incoming cold fresh air
The two air streams pass through the core, exchanging heat
but never actually mixing. Controls are programmable.
Small ducts draw stale air from the bathrooms and the kitchen.
>>Narrator: This house incorporates many products
that are recycled, reused and low-toxin: sustainably harvested Black Locust for decking,
White Oak for flooring and Aspen for walls. Reused kitchen cabinets, sealed to prevent
off-gassing of formaldehyde. Surplus tiles in the kitchen and the bathroom.
Ultra low-toxin paints and adhesives. Paint made from milk. Second-hand light fixtures.
insulation made from recycled newspapers and blue jeans.
Even the original front sidewalk was saved and reused.
>>Narrator: Sizing a house "just right"
means designing for livability as well as affordability, and efficient use of natural
resources. The house dimensions are 24 x 36 feet -- a compact 864 square "footprint".
The second floor is somewhat smaller, because the "walls" are actually the sloping roof
trusses. It will have cabinets and closets built into the areas with sloped ceilings.\
This is the 2-Bedroom version of the house,
with 1,114 square feet total, a bath-and-a-half, and an open ceiling over the
main Living/Dining areas.
>>Narrator: We're using south-facing skylights as solar heat collectors. These will have
insulating shutters and a summertime venting system built in. [Lou talking to participants]
Another innovation is the roof venting and channel system. This system gets rid of
winter-time moisture like normal venting. It also vents summer heat.
In addition, the channels form an inexpensive "faux-cold roof" feature. This design eliminates
problems of roof leaking due to the ice damming that's common in the Upper Midwest [USA].\
Sheets of housewrap material are stapled into
channels between the roof trusses. Housewrap lets water vapor pass through
permitting the insulation to stay dry.
But housewrap sheds liquid water. So if the roof ever leaks
water will drain harmlessly to the outside.
>>Narrator: We've found a way to build straw-clay walls that are simultaneously strong
& cohesive, and lightweight & well-insulating. Roughly 15 to 20% of winter heat loss of an
average house is through the exterior walls. For homes in the upper U.S. and Canada,
a wall's insulating level -- called R-value -- should be at least 20. \
We recently worked with the Forest Products Laboratory in Madison, Wisconsin,
to performthe first thermal performance tests of straw-clay in the U.S.
The Forest Products Laboratory tests confirmed that our 12 inch thick straw-clay walls achieved
an R-value of 21.
>>Lou: "The art of earthen plastering on a straw-clay wall
is tuning the permeance of the inside wall and the permeance of the outside wall
such that there's less resistance on the outside, so it's always drying to
the outside.."[continues talking]
>>Narrator: Moisture in a house -- and with it mold and mildew problems -- is another
major concern in residential construction. Modern hollow walls have plastic vapor barriers
inside and impervious exterior sheathing. When moisture gets inside, it can't get out
A solid straw-clay wall works in a different way. Clay is the mechanism that allows the
wall to transport moisture -- to dry itself from the inside out naturally.
We're currently logging daily house humidity
and temperature to quantify this beneficial effect.
>>Douglas Piltingsrud: "This is what the surface is like,
of a certain formulation...permeance testing..." [continues talking]\
>>Narrator: We're also carrying on research
into the moisture permeance and other characteristics of earthen-based plasters.\
>>Narrator: This is not the only way to build.
But it is a low-impact wa, that is durable
energy-efficient, healthy and naturally mold & mildew resistant. Straw-clay is ideally suited
to the Midwestern climate, meets building code standards, and combines
the best of conventional construction techniques with modern alternative materials and design.
[sounds of workshop machinery and people talking]