Straw Bale Building David A Bainbridge 2012 1

Straw Bale Building David A. Bainbridge 2012 1

Why straw bale? • By 1980 it had become clear the best way to build was using superinsulated passive solar design • The question was how to do it at reasonable cost? Double stud walls work but are expensive 2

The need for change • Buildings use 70% of the electricity and generate 40% of global change gases in the U. S. • They require massive amounts of energy and water • They leak toxic and ecotoxic materials • Bad indoor air costs $160 billion a year in health and lost productivity 3

Almost all impacts are avoidable If buildings are solar oriented ünaturally heated and cooled ünaturally lit ünaturally ventilated ümade with renewable and sustainable materials 4

Off grid solar straw bale • It is not costly or difficult to make very good buildings • It takes knowledge! • The designers of this house have done more than 200 solar buildings and now prefer straw bale walls 5

Straw bales fit the bill • • • Renewable Modest cost Super-insulation Fire resistant Durable Best in areas where straw is readily available - rice, wheat, oat, rye or…. . 2 string or 3 string or larger all can work 6

An American Tradition • Straw bale building developed in the Sand Hills of Nebraska • Wood was in short supply and costly • Sandy soil would not make sod walls 7

Proven Performance • Straw bale buildings were rediscovered in the 1980 s • Arthur, Nebraska has sb homes and a sb church • Standing strong 8

Early straw bale • The Fawn Lake ranch bunkhouse used straw bales • Out on the plains they provided comfort and quiet against the wind 9

1989 -- The Beginning • We gathered in Oracle, Arizona for the first modern straw bale workshop • Many things would be worked out over the next 10 years Matts Myhrman 10

Poor accounting • Buildings are not built right because of poor accounting, perverse incentives and ignorance • Life cycle costs are not considered • Good buildings pay large dividends in productivity and health 11

Research and Development • Many people and some adventurous clients helped lead the way • Matts Myhrman and Judy Knox, Steve Mc. Donald. Bill and Athena Steen, Pliny Fisk III, Ken Haggard and Polly Cooper, Steve Kemble, Bob Theis, Dan Smith, Turko Semmes, and many others contributed time and energy Bainbridge, Bill Steen, Eisenberg Theis, Athena Steen, Smith 12

Uses • It soon became clear that straw bale building was good for homes • And also for commercial buildings, schools and shops Winery, SLO 13

Workshops led the way • People helping people provided funding and inspiration • Workshops provided labor and offset costs for resource limited families and companies 14

Tree of Life • Mike Evans and Steve Bohn hosted several workshops • Many people were inspired by their workshop experiences • They realized “We can do this!” Nursery office - straw bale 15

The Canelo Project • Bill and Athena also teach and host bale building workshops • They even built a sb on the Capitol Mall one year 16

Bale building • Bale building strategies continue to evolve • Different methods of pinning and plastering are used • Tests have confirmed strength and fire resistance 17

Stack, pin and plaster • Bales may be stacked flat or on edge • R-values are similar either way • About R 40 for a 3 string bale • R 70+ for big bales 18

Big Bales Work Too • John Glassford has pioneered use of the big bales for structures in Australia • This is good for super-insulation and very strong walls without framing 19

Bale walls • Walls may be structural or infill • After the bales are up they may need some adjustment • They may also need a haircut 20

Plastering • Plasters can be natural muds and earth plaster • Lime based • Cement based • Applied by hand or machine 21

A low impact way • The Steens have developed a very nice system of paired bamboo rods • The plate is snugged down to the bamboo pins making a level wall plate easy to do 22

Other approaches • Many other methods have been used • Code and engineering issues may determine which is right for you • Seismic stability looks very good 23

A Trial by Fire • Architects Ken Haggard and Polly Cooper were in Europe when a wildfire burned their wood frame home and office • The only survivor was a straw bale bench 24

Straw bale preferred • They rebuilt with a passive solar straw bale design • And went off grid • Careful detailing was done to minimize future fire risk SLOSG straw bale architects office 25

Water Wall Passive Solar • Their house was also rebuilt with straw bales and passive solar heating and cooling, solar hot water and PV solar electricity • It works well 26

More straw bale projects • They began to use straw bales on most of their projects • This SLOSG designed synagogue in San Luis Obispo uses 91% less energy than required by the state energy code Title 24 27

Straw bale for many uses • Straw bale homes are most common • But wineries have also been enthusiastic adopters for tasting rooms, production facilities and storage 28

Safari Park • The seed lab at the SD Zoo Safari Park is built with straw bales 29

Public Buildings • Police substations in Visalia use passive solar design and straw bales • More comfortable, economical and blast resistant • Indigo Architecture, Jonathan Hammond 30

Straw Bale Building • The goals of the sustainable building movement are to improve comfort and health of the built environment • Straw bales will play a key role – Increase comfort – Increase security – Quiet and stress reducing – Maximize use of renewable resources – Minimize life-cycle costs • Reduce global change impacts 31

One of the best alternatives • Straw bale has many advantages and a few disadvantages • Other options include – Straw/clay – Adobe – Rammed earth – Cob – Wood truss or double wall – Structural insulated panels (SIPS) 32

Energy cost BTU/lb • • Straw Adobe Concrete Wood Copper pipe PVC plastic Steel pipe Galvanized steel 100 170 650 1, 000 73, 000 35, 000 26, 000 15, 000 33

Performance BTU/SF YEAR Type Nonsolar Wall Wood Adobe Simple solar Straw bale Roof pond Straw bale El Centro 54000 53000 9500 900 Denver 48500 1400 0 65000 34

Why aren’t there more straw bale buildings? • Subsidies for fossil fuels and wood • Dominance by the developer rather than users, clients, renters or homeowners • Failure to consider system integration • Minimal planning (a failure of street layout and engineering design) • Financing pressure • Ignorance 35

A Better Future • Well designed passive solar straw bale buildings can improve comfort and reduce energy use 80 -90% • Simple straw bale buildings cut energy use in Mongolia 60% • Using bales also sequesters carbon 36

Counting the true cost Per Kwh Passive solar -$2 to 5¢ Wind 6 -7¢ Oil 10 -20¢ Coal 10 -30¢ Nuclear 20+¢ External costs included 37

Straw bale solar • Straw bale makes for energy efficient building shells but needs passive solar design to perform best • Orient correctly for high summer sun and low winter sun • Minimize heat loss/gain • Use daylight and direct sun • Optimize natural breezes 38

What are we waiting for? • The Solar Spring-- A popular revolution! • Demand true cost accounting • The special interests who benefit don’t want change to happen • They want oil, coal and natural gas profits Write your politician and tell him/her you want straw bale solar building now! 39

With true cost accounting • Everyone would think straw bale passive solar first • They might use a solar clothes dryer • They would use solar hot water • Solar electric systems would be common • Health and prosperity would be on the rise! 40

Reading • Passive Solar Architecture. 2011. Ken Haggard and David Bainbridge • Design of Straw Bale Buildings: The State of the Art. 2006. Bruce King • Serious Straw Bale: A Home Construction Guide for All Climates. 2000. Paul Lacinski and Michel Bergeron • The Straw Bale House. 1994. Bill & Athena Steen, David Bainbridge, David Eisenberg 41