Efficient Agricultural Buildings: An Overview

1. Efficient Agricultural
Buildings: An Overview
FARM ENERGY SYSTEMS GUIDE
Abstract: Efficiency-focused building designs reduce the use of materials and energy in building construction and
operation. Planning for efficiency can help save money and improve building performance. This publication discusses
several ways to improve the efficiency of agricultural buildings and provides further references for implementing those
strategies. Topics covered include suiting a building to its site, using natural systems, using renewable energy, conserving
energy, and conserving material resources in construction.
By Tracy Mumma
NCAT Agricultural Energy Specialist
November 2002 Introduction
Efficient buildings can save money and im-
Table of Contents prove comfort while reducing resource consump-
tion. Designers and builders nationwide are cre-
ating new buildings that save energy and water,
Introduction ......................................... 1 use fewer material resources, and create less
Matching Building to Site .................... 2 waste. Through the U.S. Green Building
Using Natural Systems ....................... 3 Council’s LEED rating system (1), the federal
Energy Star® certification (2), and green build-
Renewable Energy for ing programs in states and communities, the
Agricultural Buildings ..................... 5 building industry is developing standards that
help measure and compare building efficiency.
Energy Conservation in
Several awards programs recognize green build-
Agricultural Buildings ..................... 6 ings, and professional organizations provide
Resource Conservation in Agricultural training for designing and constructing more ef-
ficient buildings (3). From architects to contrac-
Building Construction ..................... 8
tors to owners, more people are recognizing the
Other Efficiency Strategies for benefits of efficient building and implementing
Agricultural Buildings ........................ 12 efficiency strategies in their building projects.
You don’t have to participate in any special pro-
Summary ........................................... 12 gram to practice and enjoy the benefits of effi-
References ........................................ 13 cient building. Farmers and ranchers can join in
Further Resources ............................ 14 the savings by incorporating efficiency in their
plans for new buildings or renovations. Whether
Web-based Resources ..................... 14 you are planning housing, barns, equipment
sheds, greenhouses, storage spaces, or even spe-
cialized facilities for agritourism or product pro-
cessing, efficiency is an important consideration.
ATTRA is the national sustainable agriculture information service operated by the National Center
for Appropriate Technology under a grant from the Rural Business-Cooperative Service, U.S.
Department of Agriculture. These organizations do not recommend or endorse products,
companies, or individuals. ATTRA is headquartered in Fayetteville, Arkansas (P.O. Box 3657,
Fayetteville, AR 72702), with offices in Butte, Montana, and Davis, California.

2. One of the challenges of efficient building is cases, this may require a sophisticated blending
that there is no single solution that applies in ev- of local design wisdom with state-of-the art tech-
ery instance. Depending on where a building is nology.
located, what its purpose is, and how long it will One of the first steps in building construc-
be needed, the most efficient design and materi- tion is site selection. Savvy designers recom-
als for a particular situation may be very differ- mend careful study of potential sites, to identify
ent from the best options for other circumstances. how they are affected seasonally by water, wind,
An unheated storage and sun (5). Mapping or
building, a large barn, recording the incidence
and a home all have of these forces over the
Efficient building principles
different require- course of a year can help
ments for comfort, identify the best site for a
• Minimize operating energy.
function, and effi- building on a particular
• Incorporate renewable energy wherever
ciency. In general, the piece of property. An-
possible.
most efficient building other important consid-
• Optimize material use with the fewest,
is one that is respon- eration for building is the
best materials.
sive to its local cli- substrate of the site.
• Design for local conditions; build with
mate, efficiently con- Some soil conditions
local materials.
structed of locally ob- make construction so ex-
• Conserve resources in design,
tained materials, and pensive as to be imprac-
construction, and operation.
requires minimal en- tical, while just a slight
ergy to operate and change in terrain can
maintain. This publi- mark a completely differ-
cation discusses some of the strategies for effi- ent—and more suitable—soil type. Building on
cient building, such as using natural systems for less-stable soil is often possible with specially
building comfort, using renewable energy in ag- designed foundations, but the difficulty of such
ricultural buildings, and conserving energy, ma- construction can add significantly to the cost. It’s
terials, and water. Sources of detailed informa- best to seek a stable, well-drained soil that can
tion are provided in the Further Resources sec- support some type of standard foundation,
tion. whether that be pier, slab on grade, conventional
poured footings, or a frost-protected shallow
foundation.
Once you identify a building site, it’s time to
Matching Building review your priorities for the building itself, to
to Site come up with the most efficient design for the
location and situation.
• How big does the building need to be?
• How can the design work with the features
In many parts of the country, buildings that of the site?
predate the era of central heating and cooling of- • Does the building need to be permanent, or
ten employ locally developed adaptations to cli- will a temporary structure suit the purpose?
mate. For example, buildings in extremely • Does the building need supplemental heat-
snowy regions are characterized by steep roofs, ing and cooling, or can natural processes
long roof overhangs, and tight construction. In maintain comfort?
hot climates, shading and ventilation are impor- • What materials are available locally?
tant design considerations (4). This vernacular
architecture—designs and details developed for
a specific local climate—has become rarer as rela- Related ATTRA Publications
tively inexpensive energy and sophisticated tech- • Learning More about Wind-powered
nologies have made it possible to create artifi- Electric Systems for Homes, Farms, and
cial indoor climates. Yet climate creation comes Ranches
at a high cost. The most efficient and least costly • Anaerobic Digestion of Animal Wastes
long-term solution is to design a building that is • Organic Alternatives to Treated Lumber
responsive to the location it will occupy. In some
PAGE 2 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

3. The interior light gained from windows can
be increased by beveling the window opening
Using Natural Systems to allow more light to enter the room. This is
particularly true for structures with thick walls,
where incoming light can otherwise be severely
The more energy a building can capture pas- limited by the depth of the opening.
sively from natural forces, the less the owner has For buildings without windows, for interior
to pay to operate it. In temperate climates there rooms, or for spaces in the middle of large open
may be little challenge in keeping a building com- buildings, a skylight may offer the best
fortable for people or animals without supple- daylighting option. There are several alternatives
mentary energy, but in more extreme climates it available, ranging from fixed or operable clear-
takes careful planning to put nature’s energy to glass skylights to diffused-tube skylights to trans-
work heating or cooling your building. Fortu- lucent roofing material. Translucent roofing is a
nately, the savings potential is usually well worth realistic option only in the relatively few areas
the extra effort. where roof insulation isn’t of greater value than
the amount of light gained, such as in very tem-
DAYLIGHTING perate climates or in unheated buildings. Mean-
while, clear-glass skylights may actually provide
Daylighting involves direct use of the sun to
too much lighting in some situations. Glare and
light the inside of a building. It may provide the
overheating of the area directly below the sky-
sole light for a building that is used infrequently
light can be problems. Operable skylights can
or only during the day. It can also be used in a
be valuable tools for ventilation as well as light-
self-adjusting or manually adjusted system that
ing, but they are expensive and can cause water
maintains a steady level of light by supplement-
damage if improperly installed.
ing with artificial light when daylight is insuffi-
In situations where a lot of light is needed,
cient.
or where light must penetrate deep into a build-
Windows are the most familiar way to let in
ing, exterior appliances such as light shelves or
daylight. In many climates, however, inefficient
reflectors can be applied to boost daylight’s reach.
windows lose more heating and cooling energy
This type of equipment can not only multiply the
than they gain in lighting energy (6). Conse-
effect of daylighting, it can also improve the qual-
quently, it’s important to
ity of the light by diffus-
budget for the most effi-
ing and redirecting it.
cient windows possible
Such appliances can help
and to place them where
to improve the energy con-
natural light is most
tribution of windows, in
needed and energy loss is
situations where the
held to a minimum.
added investment is justi-
Looking at sun-angle
fied (7).
charts for a particular lati-
For information on
tude and season can help
daylighting and examples
identify the optimum as-
of its application, see the
pect and height for win-
Further Resources section.
dow placement. (For very
detailed information on NATURAL
solar calculation, see the
VENTILATION
Solar Position and Inten-
sity calculator available Operable windows
from the National Renew- and/or skylights can aid
able Energy Laboratory at in ventilation and provide
<http://rredc. nrel.gov/ cooling, especially in cli-
solar/codes_algs/ mates where the day and
solpos/> or consult the night temperatures differ
passive-solar design soft- significantly. Land forms
ware cited below.) and vegetation can also
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 3

4. help to channel breezes for increased ventilation the heat from the summer sun high in the sky.
efficiency. In warmer areas, these simple mea- The optimal height of windows from the ground
sures may need to be augmented to provide ad- and the size of overhang needed to shade them
equate cooling. from the summer sun can be calculated for dif-
One means of providing greater cooling for ferent latitudes in the United States by using sun-
a building than simply opening the windows is angle tables or software (see the Further Re-
a cooling tower that vents hot air out the top of sources section). The right amount of window
the building and pulls in cooler air from the low- area and the correct configuration of shading can
est level of the structure. The concept is gener- make the difference between a comfortable natu-
ally familiar to farmers, many of whom have seen rally-heated building and a space that feels like
it at work in barn cupolas. For greatest efficiency an oven.
the upper-level vents should be operable, to pre- In a structure with passive solar heat, cap-
vent undesirable heat loss in winter, and incom- turing heat from the sun is only part of the battle.
ing air should be drawn from the lowest level Storing it to help moderate night-time tempera-
through a “stack” design (8). In some desert cli- ture swings is also a key element in a passive
mates, the effectiveness of cooling towers is in- solar design. Storage capacity is provided by
creased by drawing incoming cool air over a pool thermal mass within the structure. There are
or tank of water, to add evaporative cooling. In- many options for providing thermal mass, rang-
troducing moisture to the incoming air can help ing from special interior walls containing barrels
aid cooling in arid areas, although it doesn’t work of water to dark-colored stone flooring. When
at all in humid climates. energy-efficient windows are used in conjunc-
Another idea that can be adapted from desert tion with a thermally efficient and well-sealed
architecture is the wind catcher. These air col- building envelope, however, the mass of ordi-
lectors face into the prevailing wind, and funnel nary flooring and interior walls may be enough
moving air into occupied spaces to provide a to modulate building temperature and help pro-
cooling breeze (9). The effectiveness of a wind vide for occupant comfort. In northern climates
catcher obviously depends on available air cur- it is critical to include night insulation measures
rents. The Further Resources section lists sources for windows in passive solar designs. Otherwise,
of information on natural ventilation strategies. in climates with over 6000 heating degree days—
the cumulative number of degrees in a year by
PASSIVE SOLAR which the mean temperature falls below 65°F.—
windows that are supposed to provide heat gain
In many locations the sun is the cheapest and
can actually cause a net heat loss. (Maps show-
most reliable heat source. By siting and design-
ing heating degree days and cooling degree days
ing a building for the best capture of solar gain,
for the United States are available from The Na-
the owner can reap maximum energy gain from
tional Climatic Data Center, viewable online at
a minimal investment.
<http://lwf.ncdc.noaa.gov/oa/documentli
The best orientation for passive solar perfor-
brary/clim81supp3/clim81.html>.)
mance places the long axis of a building within
There are many good references on passive
20 degrees of perpendicular to true south. This
solar design details, some of which are listed in
provides a building with solar gain from its
the Further Resources section at the end of this
southern exposure, while reducing the potential
publication. There are also many experienced
for overheating that comes from greater western
solar design professionals who can be of service.
exposure.
For best passive solar performance, the high- SHADING
est concentration of windows should be on the
building’s southern face, although generally the Often in agricultural buildings there is less
total window area should not exceed 15% of the concern with capturing enough solar heat than
building’s total floor area. Southern windows with preventing overheating. In warm climates
provide the best opportunity for solar heat gain and seasonally used buildings, preventing heat
in winter. Through careful placement and shad- gain may be the more important strategy, and
ing, these windows can capture the heat from a shading is a key means of avoiding unwanted
low-angle winter sun, while excluding much of heat buildup.
PAGE 4 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

5. Shade can be provided by vegetation, con-
structions, or a combination of the two. Quick-
growing deciduous trees are often chosen be- Renewable Energy for
cause they can provide summer shade for a struc-
ture, yet when their leaves have fallen they al-
Agricultural Buildings
low the sun to reach the building and boost so-
lar gain during the winter. Trellises can also pro-
vide window shading, especially when covered
with vines or other vegetation during the grow-
PHOTOVOLTAICS
ing season. Awnings and slatted above-window Solar electric energy systems, or photovolta-
shades are other means of protecting windows ics, can supply power for any number of remote
from heat gain during the months when the sun agricultural applications, including pumping and
is high in the sky. Information on shading strat- electric fencing. See the related ATTRA publica-
egies is included in the Further Resources sec- tions Solar-powered Livestock Watering Systems and
tion. Freeze Protection for Solar-powered Livestock Water-
ing Systems. Photovoltaics can also be used to
EARTH BERMS generate electricity for lighting buildings or op-
Another natural force that can significantly erating equipment and appliances. There are sev-
contribute to reducing energy use in buildings is eral options for solar electric systems. They can
the temperature-moderating thermal mass of the be designed to tie into the power grid as utilities
earth itself. When a building is set into a slope allow, feeding any excess power back into the
or simply set deeper than usual into the ground grid to run the meter backwards, and drawing
of a level site, the surrounding earth helps shel- power from the grid when they aren’t generat-
ter the structure from heat loss or gain. The sur- ing. At remote sites, photovoltaics team with
rounding earth acts as a thermal reservoir, mod- storage batteries to provide a reliable power sup-
erating the indoor temperature of the building ply at any time. The solar panels can be mounted
as the outside air temperature changes. There on a building rooftop that provides the right as-
are two important considerations when earth- pect and angle, or mounted in a freestanding ar-
berming buildings: the structure must be de- ray.
signed to support the pressure of the surround- One recent development in solar panel tech-
ing earth, and the building system must be pro- nology may be especially relevant to agricultural
tected from moisture in the soil. It is also worth buildings. Manufacturers are now offering sev-
checking the average annual ground temperature eral roofing products that combine roofing ma-
of the building site, to assess whether the differ- terial and photovoltaic electricity-generating ca-
ence between air and soil temperature provides pacity in a single unit. Both slate-styleand stand-
a bermed building with a significant thermal ad- ing-seam-style panels are available from Uni-
vantage. Solar products <http://www.uni-solar.com/
bipv _resid.html>. Although these products are
expensive, they can be economical for new roofs
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 5

6. at sites that are far from the power grid. When be particularly well-suited to rural sites. Small-
the cost of roofing and the cost of power genera- scale wind power, biomass generation, micro-
tion are both weighed in the balance, building- hydro power, and methane digesters are all po-
integrated photovoltaics (BIPV) can come out the tential sources of renewable power for agricul-
winner for some locations (10). tural buildings. More information is available
in the ATTRA publications Learning More about
SOLAR HOT WATER Wind-powered Electric Systems for Homes, Farms,
and Ranches and Anaerobic Digestion of Animal
Solar water-heating systems range from the
Wastes.
simple and homemade to the complex and ex-
pensive. Generally they serve to preheat water
before it reaches a conventional water heater,
minimizing the energy that the water heater then Energy Conservation in
uses to boost the water to its final temperature.
In some climates and seasons, the solar water Agricultural Buildings
heater may bring the water to full temperature
without supplementary heating. The use of most
solar water-heating systems is seasonal in cold Before investing in renewable energy genera-
climates, where systems must be drained dur- tion systems for any building, it pays to make
ing winter to prevent water in the system from sure that the building is as energy efficient as
freezing. More complex systems that heat an possible. Improving energy efficiency is gener-
anti-freeze liquid and then transfer that heat to ally a minimal investment compared to the ex-
water inside a heated space can be used through- pense of solar panels or a wind generator. The
out the year (11). For seasonally occupied or level of energy efficiency appropriate for a given
warm-climate agricultural buildings, even a building differs according to its use characteris-
simple solar hot-water system can offer energy tics. If a building is rarely occupied or heated,
savings at minimal cost. See the Further Re- energy efficiency investments won’t be as cost
sources section for additional sources of infor- effective. For occupied buildings, however, the
mation. payback time for most investments in energy ef-
OTHER RENEWABLE POWER SOURCES FOR ficiency is relatively short, making conservation
measures an easy choice for building owners (12).
BUILDINGS
In addition to the sun, many other renewable
INSULATION
power sources exist, and a number of them may Insulation is the first line of defense for
heated or cooled buildings.
Insulation increases the re-
sistance of the building to
heat flow, helping to keep
heated or cooled air from es-
caping. Insulation also pro-
vides sound-deadening
properties. Today the most
common types of building
insulation are fiberglass, cel-
lulose, or petroleum-based
foam, though many specialty
types of insulation are com-
mercially available, includ-
ing cementitious foam,
straw, and mineral fiber.
Historically, a wide range of
materials, including cattle
hair and shaved wood fiber,
PAGE 6 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

7. were used for insulation. Important concerns for most cases a double-pane window with low-e
any insulation material are that it be fire and in- coating will provide adequate energy perfor-
sect resistant, as well as thermally efficient. La- mance. The energy rating of windows is higher
bels on commercially available insulation mate- when they have an argon or krypton gas fill be-
rials generally provide evidence of compliance tween the panes, but there is some controversy
with recognized safety standards. Documenta- about how rapidly the gas fill escapes when the
tion for alternative insulation materials may be window is exposed to the low air pressure of high
more difficult to obtain or assess. altitudes (13). Building owners at high altitudes
Recommended insulation levels differ by cli- may decide not to opt for gas-filled windows,
mate. While information on residential insula- given the uncertainty of their long-term perfor-
tion is readily available, information for other mance at altitude.
types of buildings may be more difficult to come
by. However, there are several building-energy AIR SEALING
calculators that can be used to extrapolate energy Once a building has efficient walls, roof, win-
performance, and many utility companies offer dows, and doors, what’s left to improve its en-
energy audits for both their residential and com- ergy performance? Studies show that most build-
mercial customers. These audits can be a good ings have air leaks that provide escape routes for
way to identify potential for improvement, and conditioned (heated and cooled) air (14). Block-
participating in audit programs may qualify the ing air leaks with gaskets, caulk, or expanding
owner for rebates or technical assistance in un- foam can move a building’s energy performance
dertaking energy improvements. up a notch. The most common sources of air leaks
As amazing as insulation is, it can’t stand include the sill plate; window and door open-
alone as a building’s thermal defense. It’s im- ings; and wall, floor, and ceiling penetrations
portant to team insulation with other energy-ef- such as electrical boxes, plumbing lines, and re-
ficient components to achieve good system per- cessed light fixtures.
formance, the same way you combine a hat, coat, Ducts should also be sealed, particularly if
and boots to outfit yourself for winter weather. they pass through an unconditioned airspace.
Once basic levels of insulation have been Making sure that all of these areas are detailed
achieved in the walls, roof, and floor, it’s time to and sealed eliminates most major air leaks.
turn attention to preventing energy loss from the
other parts of the building. HVAC AND OTHER SYSTEMS
WINDOWS/DOORS Insulation, efficient windows and doors, and
air sealing all contribute to making the building
It’s relatively easy to add insulation to walls, envelope energy efficient, but mechanical sys-
roofs, and even floors, but when it comes to doors tems also have a role to play. Functions that
and windows, high prices often frighten consum- aren’t furnished by the natural systems described
ers away from the most energy-efficient options. above will need to be provided by mechanical
However, eliminating leaky, inefficient doors and electrical systems and appliances. Choos-
and windows can significantly improve a ing efficient systems for heating, cooling, venti-
building’s energy performance and comfort. It’s lation, and lighting helps to cut energy costs and
essentially like getting rid of a large hole in the minimize pollution, and can help support the use
wall, since many doors and windows have ex- of renewable energy on site by cutting loads.
tremely low thermal resistance compared to solid Useful guidelines are available for evaluating the
walls and roofs. Investing in the most energy- relative efficiency of many appliances and of
efficient doors and windows you can afford is a equipment like furnaces and light fixtures. One
good choice for your building. standard is the Energy Star certification, which
Although there are state-of-the-art applies to a wide range of products. Qualified
“superwindows” available that are nearly as products and their manufacturers are listed on
insulative as most walls, they are very expensive the Energy Star website <http://www.energy
and probably aren’t warranted, except for very star.gov>. Another directory of energy-efficient
specialized applications where exceptional ther- products, which is updated regularly, is the Con-
mal performance is necessary (e.g., coolers). In sumer Guide to Home Energy Savings from the
American Council for an Energy-Efficient
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 7

8. Economy, and its companion listing, The Most the site with insulation already installed, or struc-
Energy-Efficient Appliances, available through tural insulated panels that can be used for walls,
<http://www.aceee.org/consumer guide/ floors, or roofs. Structural insulated panels sand-
index.htm>. These inexpensive references can wich a layer of foam between two faces, usually
be useful aids in finding and selecting energy- made of oriented strand board. They offer ex-
efficient equipment. cellent energy performance, because they greatly
In buildings where lights are used infre- reduce the number of thermal bridges—uninter-
quently, standard incandescent lighting will suf- rupted paths of heat loss—across the wall from
fice, but where lights are used for more than a inside to outside. They also provide good sound
few hours each day, fluorescent lighting is more attenuation, and an experienced crew can as-
energy efficient. Either fluorescent tubes or com- semble them quickly. An inexperienced crew
pact fluorescent lighting can be used, depend- will take longer to assemble the panels, and may
ing on the amount of light needed. In situations be reluctant to work with them at all, so it’s im-
where lighting is used in temperatures below portant to coordinate the building crew with the
freezing, it’s important to select a ballast that is material that’s going to be used.
rated for low-temperature conditions. The most Trusses for roofs are another efficient com-
efficient choice for lighting large areas is a high- ponent for buildings. Using roof trusses instead
intensity discharge lamp, typically a metal ha- of building a roof system on-site can save mate-
lide lamp. rial and labor costs, although setting trusses of-
ten requires a crane.
A comparatively efficient building system
that has recently grown in popularity is insulat-
ing concrete forms. These permanent foam forms
Resource Conservation provide an insulative framework into which re-
in Agricultural Building inforced concrete is poured to form below- or
above-grade walls. Foam forms come in either
Construction interlocking blocks or large panels, depending
on the particular system. Although some sys-
tems claim to be owner-friendly enough for be-
ginners to assemble, many companies require a
certified applicator on site, to help make sure that
There are many different strategies that can
the forms are properly braced and leveled, and
help produce efficient agricultural buildings.
that the concrete pour goes smoothly. Insulat-
With many types of buildings and many differ-
ing concrete form systems are more expensive
ent materials, the possibilities are almost endless.
A few guidelines can help the builder navigate
the available choices.
EFFICIENT SYSTEMS
One of the basic tenets of resource-efficient
construction is to employ building systems that
use minimal material. Engineered and pre-as-
sembled building components can use mate-
rial very efficiently, and they also help to elimi-
nate waste at the job site and speed construc-
tion. Although engineered systems may be
more expensive than conventional frame con-
struction, there are situations where assured
performance, quick assembly, and minimal on-
site labor are exactly what the owner needs, and
can offset any added cost.
Pre-assembled panels may be conventional
wood-framed wall panels that are delivered to
PAGE 8 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

9. than wood framing, but they provide an ex- wall cavities, or mixed with adhesives and
tremely durable building that offers thermal per- sprayed onto the interior of industrial buildings.
formance, sound attenuation, and fire resistance. Cellulose insulation is renowned for its ability
Turning to foundations, an especially re- to prevent air infiltration in addition to furnish-
source-efficient system that reduces both exca- ing thermal resistance. There are many cellulose
vation costs and cement use is the frost-protected insulation manufacturers located in rural areas.
shallow foundation. This system, long in use in These manufacturers often rely on local news-
Scandinavia and used by a few builders in the paper recycling to provide their raw material.
United States for decades, relies on insulation In addition, there are many recycled plastic
around the foundation perimeter to stabilize a products used in building construction for many
heated building, rather than extending footings different applications. Recycled plastic panels
below the frost line. Information on designing are popular in some livestock barns because they
and installing a frost-protected shallow founda- are easier to clean than wooden panels. Center
tion is available from the National Association Industries (880 1st Ave. NW, Sioux Center, IA
of Home Builders via their website <http:// 51250, 712-722-4049, http://www.center-
www.nahb.com/builders/frost.htm>. industries.com/Window.html) makes windows
with a recycled plastic frame specifically for ag-
RECYCLED MATERIALS ricultural use. Meanwhile, recycled plastic lum-
Another approach to resource-efficient build- ber manufacturers offer a variety of posts and
ing is to use recycled materials. These are mate- dimensional products useful for farm applica-
rials that have been removed from the waste tions, including fencing, boardwalks, bridge
stream and reprocessed to make another prod- decks, retaining walls, and raised beds. See the
uct. Although recycled products are seldom less ATTRA publication Organic Alternatives to Treated
expensive than conventional materials, they do Lumber for more information on recycled plastic
divert waste and conserve resources and energy lumber products. The American Plastics
in their manufacture. Also, some recycled mate- Council’s Recycled Plastic Products Directory in-
rials have performance attributes that make them cludes a section of products for Farming and
the best choice for a particular application. Agriculture, online at <http://sourcebook.
Cellulose insulation is typically made from plasticsresource.com/category.asp?/Farming
recycled newsprint, treated with borate additives +&+Agriculture>.
to provide fire and insect resistance. Cellulose
REUSED BUILDING MATERIALS
can be blown loose into ceilings, wet-sprayed into
Unlike recycled products,
which are reprocessed into a
new form, reused products are
salvaged and reapplied in the
same form. Most farmers and
ranchers are old hands at reus-
ing building materials time and
again, in one application after
another, and in remodeling ex-
isting buildings to serve new
uses.
There is a market for vintage
buildings, including agricultural
buildings, in reasonably good
condition. Even if the whole
building is not salvageable for
resale, individual components
may be. A number of compa-
nies specialize in remilling old
beams to make flooring, or sell-
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 9

10. ing antique beams intact for reuse. If a farm tos is regulated by law (17). Non-friable forms
building project involves demolition of an exist- of asbestos, which are less apt to become airborne
ing structure, it may be worth checking with a because they are bound in composite materials,
professional building-salvage operation to see may appear in unexpected building materials,
whether there is market value for the materials. such as old fiber-cement siding, floor tiles, or
Conversely, it may be worth considering re- sheet flooring. Although not classified as haz-
used materials for new farm structures. The pos- ardous materials, these asbestos-containing ma-
sibilities are endless, ranging from old windows terials are not desirable for reuse.
for cold frames or greenhouses to salvaged and
reused metal roofing (15). (Some landowners ALTERNATIVE TECHNOLOGIES
have even accepted clean gypsum drywall scrap In much of the world, building technologies
from building contractors to use as a weed sup- that we might consider alternative in the United
pressant and soil amendment in orchards and States are widely accepted and practiced. Some
fields. Although the effects of gypsum drywall of these traditional material technologies may be
waste as a soil amendment have been studied in viable and effective options for agricultural build-
controlled settings, on a few crops, widespread ings in the United States, providing they are
field application experiences are still lacking adapted to meet safety requirements such as fire
(16).) and seismic codes.
There are also important cautions to observe The majority of buildings on Earth are actu-
in reusing some types of building materials. Old ally built of earth. Earth is obviously a widely
paint on wood is likely to contain lead, so it’s available, low-cost building material, although
important to consider how this wood can be it has some drawbacks in its high maintenance
safely handled and where it can be applied or requirements and seismic instability, as well as
disposed of properly. Other salvaged wood may its comparatively low insulation value. In re-
be treated with preservatives that are not desir- gions of the world where earthen building is
able for residential or organic agricultural appli- commonplace, there is some concern about soil
cations. Also, note that wood that is reused for depletion that could have a negative impact on
structural uses in residences or commercial build- agriculture, but this seems unlikely in the United
ings will need to be regraded by a certified lum- States. By adapting ancient technologies, today’s
ber grader in most jurisdictions. earth builders are overcoming many of the dis-
Finally, beware of asbestos contamination in advantages associated with earthen construction
used building materials. Asbestos fibers as used and making earth a relevant and useful building
in insulation are a hazardous material because material for the present day.
they can become airborne and be breathed in. Typically massive and thick, earthen walls
The removal and handling of this type of asbes- have good thermal per-
formance because their
mass slows the rate at
which the temperature
inside the building
changes. In milder cli-
mates, with cool nights
and warm days, this
thermal mass factor
alone may be adequate
to maintain a comfort-
able temperature. De-
signs with thick walls
require special consider-
ations, since thick walls
reduce usable interior
space compared to the
building’s footprint, and
can make door and win-
PAGE 10 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

11. dow installation challenging, as well as compli- and a number of medium-density fiberboards.
cating daylighting. The fiberboard products, which are commonly
Earthen building systems include traditional used for flooring underlayment, cabinets, and
adobe block and rammed earth, and systems that shelving, can also be made from other agricul-
mix earth and fiber. Modern adaptations of these tural fibers such as bagasse, rice hulls, and hemp.
techniques include equipment that fabricates Agricultural fiberboard manufacture is a capital-
earth blocks mechanically at the building site and intensive and expensive process, and many
Pneumatically Impacted Stabilized Earth (PISE) manufacturers, including some farmer-owned
that is sprayed onto walls with a hose at high cooperatives, have struggled to establish them-
pressure. To help earthen buildings better with- selves in the marketplace. In areas where
stand the weather, systems have been invented strawboard manufacturing facilities are able to
that combine earth with asphalt or gypsum (18). operate successfully, they provide a strong mar-
There is even a system developed by architect ket for straw, as well as a useful building prod-
Nader Khalili of the Cal-Earth Institute <http:// uct derived from agricultural fiber.
www.calearth.org> that uses bags of sand Another building technology based on agri-
bonded with barbed wire to build domed struc- cultural fiber, although in a less-processed form,
tures. Modern earth-building can make use of is straw-bale building. Originating in Nebraska
equipment that reduces labor requirements, ad- more than 70 years ago, the building system uses
ditives that improve weather resistance, and en- a running bond of straw bales as walls and has
gineered support structures that enhance seismic enjoyed a revival during the past ten years. Straw
performance. For examples of modern earth- bales have been used to build homes in at least
building in the United States, see the Further 38 states, as well as countless non-residential
Resources section. buildings ranging from chicken coops and stor-
Earth buildings are worth considering for age sheds to camp dining halls. Straw-bale build-
some agricultural applications, particularly in ings may be either load-bearing, in which the bale
mild climates with good building soil. The best walls support their own weight and the weight
building soil contains coarse sand or aggregate, of the roof, or non-load-bearing, in which a con-
fine sand, silt, and clay. Although the propor- ventional wood or steel structural framework is
tions of these constituents can vary somewhat, infilled with bales that provide the wall insula-
the ideal building soil mix based on averages has tion. Straw-bale residences are often finished
been offered as 23% coarse sand or aggregate, with a cementitious stucco, although it is pos-
30% fine sand, 32% silt, and 15% clay (19).
Soils that differ substantially from this
composition will most likely require ad-
ditives for successful earth building. A
careful assessment of the soil at the site
and local sources of soil amendments can
help determine the suitability of a par-
ticular location for an earthen building.
A common way to roughly assess soil
composition is the “jar test” in which a
soil sample is placed in a glass jar, cov-
ered with water, vigorously shaken, and
then allowed to settle until the water is
clear. Coarse aggregates will settle in a
band at the bottom, sand and silt in the
middle, and clay on top.
Farmers may be particularly inter-
ested in building technologies based on
agricultural fiber. There are several
manufactured building materials made
from straw, including ceiling panels, a
variant of the structural insulated panel,
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 11

12. sible to finish interiors with gypsum wallboard Installing water-conserving fixtures and ap-
and exteriors with different siding options. In pliances usually saves costs in building operation,
some agricultural buildings owners have left bale for both water and the energy needed to heat and
walls unfinished, recognizing that this leaves move it. There are also several options for treat-
them vulnerable to damage from livestock and ing used water, ranging from complex closed-loop
weather. treatment systems based on the ecological struc-
Some farmers have used bales to construct ture of a marsh (20) to less-involved constructed
winter livestock shelters, and intentionally left wetlands (21) or sand filters. In some jurisdic-
the bales exposed to serve as emergency food for tions greywater (as opposed to blackwater, or
the animals. In these applications the roof would sewage) can be stored and used for irrigation of
need to be supported by a separate framework, trees or nonfood vegetation. (See the Greywater
and the walls themselves well supported, to pre- website at <http://www. greywater.com/> for
vent their collapse. The weathered bales are then additional information.)
removed in the spring, allowing the roof to serve Buildings can also play a role in capturing
as a shade shelter during summer. rainwater for either drinking or irrigation. Roof-
Straw-bale construction’s recent rise in popu- top water-catchment systems vary in complexity
larity can be partly attributed to its intuitive, eas- from simple rain barrels placed at the bottom of
ily grasped assembly process. Many owners gutters to systems that collect runoff that is stored
have reduced building costs by investing their in a cistern and treated for drinking. For more
own sweat equity or employing work parties of information on designing and installing rainwa-
unskilled labor. However, it is important to rec- ter collection systems, see the Further Resources
ognize that the wall system is typically less than section.
15% of a building’s cost, so the savings provided
by a homegrown wall system are limited. Also
note that subcontractors (i.e., electrical, cabinetry,
drywall, etc.) may charge more when working Summary
with an unfamiliar construction system that
forces them to modify their standard installation
practices. Designing and constructing agricultural
When straw-bale walls are well protected buildings with efficiency in mind saves money,
from moisture by a good foundation, a sound energy, and resources. Employing strategies such
roof, and a good exterior covering, they offer a as natural ventilation, passive solar heating, and
durable structure with good thermal perfor- daylighting are some of the ways that building
mance. Few buildings can be as resource effi- owners can put natural systems to work for them.
cient, or as locally derived, as a straw bale build- By combining energy efficiency and renewable
ing. energy options, agricultural buildings can move
toward energy independence. And finally, agri-
cultural buildings can be built from a range of
resource-efficient materials geared to meet almost
Other Efficiency any need, whether that be for a temporary struc-
Strategies for ture or a high-performance specialty building.
Agricultural Buildings
Energy and material are the primary re-
sources used in buildings. When the use of these
resources during construction and operation is
reduced, the cost of a building and its impact on
the environment are both lessened. There are
additional opportunities to make buildings more
efficient, as well.
PAGE 12 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

13. 10) Wilson, Alex, and Peter Yost. 2001.
Building-Integrated Photovoltaics:
References Putting Power Production Where It
Belongs. Environmental Building News.
March. p. 1, 8-14.
1) U.S. Green Building Council 11) North Carolina Solar Center. 1998. Passive
1015 18th St. NW, Suite 805 and Active Solar Water Heating Systems.
Washington, DC 20036 North Carolina Solar Center Factsheet
(202) 82-USGBC SC104 . Accessed September 2002. <http:/
info@usgbc.org /www.ncsc.ncsu.edu/fact/
<http://www.usgbc.org> 04pasdhw.html>
2) Energy Star 12) Rocky Mountain Institute. No date.
(888) STAR YES Energy Efficiency: First Things First.
http://www.energystar.gov Rocky Mountain Institute. Accessed
3) National Association of Home Builders August 2002. < http://www.rmi.org/
Research Center sitepages/pid195.php>
(National Green Building Conference, 13) Yost, Peter, and Alex Wilson. 2000. High
Green Building Awards and Energy Elevation Problems Jeopardize Gas-Fill
Value Housing Awards) Windows. Environmental Building News.
400 Prince George’s Boulevard April. p. 1, 15-18.
Upper Marlboro, MD 20774
(301) 249-4000 14) Krigger, John. 2000. Residential Energy.
(800) 638-8556 Third Edition. Saturn Resource
<http://www.nahbrc.org> Management, Helena, MT. p. 67-95.
4) Watson, Donald and Kenneth Labs. 1983. 15) Corson, Jennifer. 2000. The Resourceful
Climatic Building Design. McGraw-Hill, Renovator. Chelsea Green Publishing,
New York, NY. p. 3–18. White River Junction, VT. 157 p.
5) Rocky Mountain Institute. 1998. Green 16) Stehouwer, R.C. 2002. Section 9:
Development. John Wiley & Sons, New Nontraditional Soil Amendments. The
York, NY. p. 124–255. Agronomy Guide. Penn State University.
Accessed August 2002. <http://
6) Efficient Windows Collaborative. No date. agguide.agronomy.psu.edu/CM/Sec9/
Benefits: Energy & Cost Savings. Sec9toc.html>
Accessed August 2002. <http://
www.efficientwindows.org/ 17) Anon. 2001. Safety and Health Topics:
energycosts.html> Construction: Asbestos. U.S. Department
of Labor Occupational Safety & Health
7) Anon. 2002. Daylighting: Many Designers Administration. Accessed August 2002.
are Still in the Dark. Architectural Record. <http://www.osha-slc.gov/SLTC/
June. Accessed online at <http:// constructionasbestos/index.html>
www.archrecord.com/CONTEDUC/
ARTICLES/06_02_3.asp> 18) Middleton, G.F. 1987. Earth-Wall
Construction, Fourth Edition. CSIRO
8) Bender, Roger, and Richard Stowell. 1998. Division of Building, Construction and
Chimneys: A Natural Ventilation Engineering, North Ryde, NSW,
Alternative for Two-Story Barns. Ohio Australia. p. 59-61.
State University Fact Sheet. Accessed
August 2002. <http://ohioline.osu.edu/ 19) McHenry, Paul Graham Jr. 1984. Adobe
aex-fact/0115.html> and Rammed Earth Buildings. University
of Arizona Press, Tucson, AZ. 217 p.
9) Brown, G.Z., and Mark DeKay. 2001. Sun,
Wind & Light. John Wiley & Sons, New
York, NY. p. 188–200.
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 13

14. 20) Living Machines, Inc. Sun, Wind & Light: Architectural Design
125 La Posta Road Strategies, second edition. 2001. By G.Z.
8018 NDCBU Brown and Mark DeKay. John Wiley and
Taos, New Mexico 87571 Sons, New York, NY. 382 p.
(505) 751-4448
An in-depth technical reference addressing
<http://www.livingmachines.com>
analysis techniques, design strategies, and
21) Anon. No date. Constructed Wetlands for strategies for supplementing passive systems.
Wastewater Treatment. Partnership for
Advancing Technology in Housing
(PATH) Technology Inventory. Accessed
August 2002. <http://www.toolbase.org/ Web-based Resources
tertiaryT.asp?DocumentID=2158&Category
ID=1071>
Adobe International
http://www.adobe-block.com/
Further Resources Portable equipment for mechanically manu-
facturing earthen blocks at the building site.
Daylighting Collaborative
Builder’s Guide. 2000. By Joseph Lstiburek. http://www.daylighting.org
Building Science Corporation, Westford, Information on daylighting buildings, includ-
MA. ing benefits of daylighting and an extensive
The Builder’s Guide series from the Energy how-to section with interactive online
and Environmental Building Association worksheets. Case-study buildings are also
presents a systems approach to designing and featured.
building healthy, comfortable, durable, energy Design Recommendations for Natural
efficient, and environmentally responsible Ventilation Systems
homes. Separate versions are available for http://www.ae.iastate.edu/
each climate type: Cold, Mixed, Hot/Humid design_recommendations.htm
and Hot/Dry. $40 each from EEBA, <http://
www.eeba.org>. An electronic publication on natural ventila-
tion for livestock facilities from the Depart-
Climatic Building Design. 1983. By Donald ment of Agricultural and Biosystems Engi-
Watson and Kenneth Labs. McGraw Hill neering at Iowa State University that provides
Book Company, New York, NY. 288 p. guidelines for placing buildings and sizing
This comprehensive reference presents prin- ventilation openings.
ciples of climatic design related to ventilation, Designing with the Pilkington Sun Angle
cooling, solar gain, and more, as well as Calculator
practices and supplemental climatic data. http://www.sbse.org/resources/sac/
Serious Straw Bale. 2000. By Paul Lacinski pnasac.htm#thesac
and Michel Bergeron. Chelsea Green Detailed online information on how sun angle
Publishing, White River Junction, VT. calculations are performed and applied in
371 p. building design. Includes discussions of solar
Billed as “A Home Construction Guide for All orientation, designing overhangs, daylighting,
Climates,” this reference addresses different and solar heat gain.
elements of straw-bale structures, as well as
finish options, moisture studies, and experi-
mental constructions.
PAGE 14 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW

15. Landscaping for Energy Efficiency Solar Water Heating
http://www.eren.doe.gov/erec/factsheets/ http://www.eren.doe.gov/erec/factsheets/
landscape.pdf solrwatr.html
A factsheet available as a PDF file from the A basic factsheet on residential solar water-
Energy Efficiency and Renewable Energy heating technology, from the U.S. Department
Clearinghouse on using trees and other of Energy Office of Energy Efficiency and
landscaping to help mitigate hot and cool Renewable Energy.
temperatures in different climates and micro-
SunAngle calculator
climates.
http://www.susdesign.com/sunangle/
Lawrence Berkeley National Laboratory—
Online shareware that can be used to calculate
Windows & Daylighting Group
optimal angles for solar design, for a fee of $10
http://windows.lbl.gov/
for individuals, or $25 for professionals.
Information on daylighting products and
Texas Water Development Board’s page on
controls.
Rainwater Harvesting
NCAT Center for Resourceful Building http://www.twdb.state.tx.us/assistance/
Technology conservation/Rain.htm
http://www.crbt.ncat.org
Offers the PDF version of the Texas Guide to
Information on resource conservation in Rainwater Harvesting and a list of rainwater
buildings, including a searchable database of catchment systems, services, and equipment
manufacturers of efficient systems, recycled providers.
and reused building materials, as well as
alternative building technologies.
Passive Solar Design for the Home
http://www.eren.doe.gov/erec/factsheets/
passive_solar.html By Tracy Mumma
NCAT Agricultural Energy Specialist
A fact sheet from the U.S. Department of
Energy Office of Energy Efficiency and
Edited by Paul Williams
Renewable Energy that explains the basic
principles of how passive solar strategies can Formatted by Gail Hardy
help heat and cool homes.
November 2002
Rainwater Harvesting Wizard
http://www.captured-rainwater.com/
A fee-based information website where consul-
tation on rainwater harvesting system design IP220
and equipment is provided to answer online
inquiries.
The electronic version of Efficient Agricul-
Rammed Earth Works tural Buildings: An Overview is located at:
http://www.rammedearthworks.com/ HTML
Founded by David Easton, this is a leading h t t p : / / w w w. a t t r a . n c a t . o r g / a t t r a - p u b /
company in the research and development of agbuildings.html
modern earth construction technologies, PDF
including rammed earth and variations such http://www.attra.ncat.org/attra-pub/PDF/
as PISE. agbuildings.pdf
//EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW PAGE 15

16. PAGE 16 //EFFICIENT AGRICULTURAL BUILDINGS: AN OVERVIEW