Posts having to do with sustainable use of materials that don’t fall under energy or water

The wildflowers planted in the meadow and now in a riot of bloom, and it seems like only half of the types have bloomed so far, so we have more colors to go.  The grasses are slowly growing in in between.  I understand from the sources I have read on Native California Grasses, that I should expect this first year to be mostly establishing root structure with a little bit of grass above the ground, and that next spring is when I can expect to see more growth.  In the mean time, however, the flowers are giving us plenty of green.

Wildflower mounds in the back

The various edible cultivars of plants that we have in the yard are being grown in “guilds” of plants with an eye towards permaculture.  Guilds are groups of plants that have been found to work very well together because they each provide something that the other plants around them need, whether it be acidification of soil, shade, nitrogen fixing or simply support for the other to grow on.  If carefully selected and sited, guilds overall require less water, harbor fewer pests, suppress weeds, and are more more productive without needing chemical fertilizers.  Our (grey water irrigated) fruit trees are interplanted with blueberry bushes.  This year we are sheet mulching around the trees and bushes to bring the new trees through the hot summer with a minimum water requirement while they establish their roots.  Sheet mulching consists of a layer of corrugated cardboard over the ground covered with compost and mulch to a foot deep and left to rot for a year, and it is excellent for suppressing weeds which otherwise would be a constant battle.  Next spring after the sheet mulching has had a year to decompose, we will interplant legumes of various sorts all through the orchard.  (You will also see that we have finally replaced our fence all the way around, getting rid of the rotting, leaning, broken eyesore that we had before and replacing it with a fence with a custom top lattice that echos the horizontal bar design theme within the house.)

The fruit tree orchard with blueberry bush interplantings, sheet mulch and the new fence visible along the right side

The citrus trees (two limes, one lemon) with feijoas, blackberry and raspberry. at the end of the path, the kiwi vines to be grown on the trellis can be seen.

Our citrus trees have pineapple guava (aka feijoa), blackberries and raspberries interplanted around them.  We haven’t yet sheet mulched that area, so in the picture you can see that the weeds are already aggressive in that area.

As part of getting the fence replaced, we needed to move all of the piles and piles of stones that we had been hoarding all over the yard for the eventual construction of two ponds and a stream in the front and middle yards.  We decided to assemble them into a dry creek bed of sorts running through the area where we will eventually have the stream so that we could plant all of the appropriate plants around that area before we built the stream (in one or two, or three years).  It ended up looking surprisingly nice, and it is extremely useful for planning where plants are going to go.  We’ve put in some douglas iris and various Juncus varieties that are difficult to grow from seed (I’ve been trying, and haven’t been too successful), and all around the stream bed on the greywater wetlands we’ve planted bull clover, so hopefully we’ll be seeing some of that coming up soon.

The dry creek running through the grey water wetlands

Other edible plants in the yard include an old fig tree that produces luscious pale green figs with bright red interiors, a couple of passiflora edulis varieties, huckleberries and currants and wild strawberries as part of the redwood understory in the front yard, and, of course, a kitchen garden of various different herbs including lots of mint for mojitos

Our mint and sage doing well in the little kitchen plot by the patio

Now that the house is in pretty good shape, it is time to start covering all of the bare earth around the house with plants.  When we worked earlier with our landscape architect, Amy Cupples-Rubiano, she had put together a beautiful design with native plants and different climate zones in the yard.  For the open, sunny, unirrigated areas the plan was for “open grasslands” – native grass and wildflower meadows that would go green in the winter rains, burst into color in the spring and then become a dormant golden brown during the summer.  For the planters nearer the house on the sunny south side that tends to get very hot from both direct sun and reflection off a sunny wall, the plan was for chaparral species like manzanita.   The shaded  areas around the fruit trees would be filled with more shaded grassland species, the front yard would have redwood understory plants in around our huge Deodara tree in the front yard (and our new tiny redwood seedlings that we hope will grow up to join our neighbor’s redwood grove).  The final “climate zones” are the greywater wetlands with rushes and bog plants that will live with their roots down in the greywater gravel leach field, and then the orchard which is watered from the output from the greywater wetlands.

It will be a multi year process getting all of these plants established, but I have started with a combination of broadcasting seeds in the meadows (seeds available from Larner Seeds, a specialty native plant seed company), starting the seeds that need more care in little greenhouse trays, and buying container plants from our local Summerwinds nursery that has a California Natives section, and, of course, the famous Yerba Buena nursery where huge numbers of native plants are available, and ordering bare root fruit trees.  Where possible, I tried seeds, as container plants run $5-$15 per container, and I have a LOT of bare earth to cover.

Seedlings in the “jiffy” planter

There will be updates as I go along, but the following plant species are the ones going into the various parts of the garden:

Open Grassland Grasses (all from seeds, sowed directly) :

  1. California Fescue (festuca californica)
  2. Blue Fescue (festuca idahoerisis)
  3. Purple needlegrass (nasselta pulchra)

Open Grassland Wildflowers (all from seeds, sowed directly):

  1. California poppy (Eschscholzia californica)
  2. Blue Thimble flowers (Gilia capitata)
  3. Tidytips (layica platyglossa)
  4. Sky Lupine (lupinus nanus)
  5. plus “hills of california” wildflower mix from Larner seeds

Shaded Grasslands (all from seeds, grown as seedlings)

  1. California Fescue (Festuca californica)
  2. Douglas Iris (Iris douglasiana)
  3. Pt. Reyes Checkerbloom (sidalcea calycosa rizomata)
  4. Blue-eyed grass (sisyrinchium bellum)
  5. Yellow-eyed grass (Sisyrinchium californicum)

Chapparal garden (all container plants except as noted)

  1. Marina Madrone Tree (arbutus ‘marina’)
  2. Western Redbud Tree (Cercis occidentalis)
  3. Manzanita densiflora (Arctostaphylos densiflora “sentinel”)
  4. Wood’s Manzanita ground cover (arctostaphylos uva-ursi ‘wood’s compact’)
  5. Western Mock-Orange (Philadelphus Lewisii)
  6. Coffeeberry (rhamnus californica ‘Eve Case’)
  7. Collingwood rosemary (rosmarinus officinalis)
  8. Dark Star wild lilac (ceanothus ‘dark star’)
  9. Blue blossom wild lilac (ceanothus thyrsiflorus) (attempting to grow from seeds, not successful yet)
  10. White sage (salvia apiana) (from seeds, grown as seedlings)

Manzanitas waiting for their planter to be made

Redwood understory (all container plants except as noted)

  1. Western columbine (aquilegia formosa) (seeds, grown as seedlings)
  2. Western sword fern (polystichum munitum)
  3. coral bells (heuchera)
  4. Redwood sorrel (oxalis oregana)
  5. Wild Ginger (asarum caudatum)
  6. Coastal strawberry (fragaria chiloensis)
  7. Shaggy Alum root (heuchera pilosisima) (seeds, broadcast… we’ll see)
  8. Evergreen Huckleberry (vaccinium ovatum)

Planting “redwood understory” with redwood bark around it

Wetlands (some container, some seed, but I had a lot of difficulty finding suitable plants!)

  1. Common horsetail (equisetum arvense)
  2. California rush (juncus patens)
  3. Slender sedge (carex praegracilis) (seed, grown as seedlings with some sown directly)
  4. Bull clover (trifolium fucatum) (seed, to be sown directly)

Orchard and fruit shrubs/vines (greywater irrigated)

  1. Pomegranate
  2. 3-in-1 cherry tree (has bing, ranier and one other type grafted in)
  3. 4-in-1 pluot tree (flavor king, flavor supreme, dapple dandy and ?)
  4. Snow queen Nectarine
  5. Blenheim apricot
  6. Pinkerton avocado
  7. Kiwi vines
  8. Varigated Eureka lemon
  9. Key lime
  10. 6 kinds of blueberries (jewel, blueray, misty, star, sharpblue and an old one I had)
  11. A heritage red raspberry (rubus idaeus)
  12. and a thornless blackberry (rubus ulmifolius)

our little fruit trees with their various grafted limbs tagged

The grey water system is now up and running!  As was detailed in earlier posts, the house is double plumbed so that water from our bathroom sinks, showers and washing machine all flow out of our grey water sewer pipes for diversion into our grey water system, and the toilet sewage and kitchen sink water (aka “black water”) flows straight to the municipal sewer.  Because our grey water exited a bit low to flow directly into our intended wetlands, we needed a sump pump to pump it back up to enter the grey water wetlands… except that those also needed to be constructed before we had anywhere for the water to go, so up until now, all the water (black and grey) has ended up in the municipal sewer.

A covered box needed to be constructed around the sump pump so the area could be buried but we would still have access to the sump pump for servicing, and the diverter valve should we ever need to bypass the wetlands and start dumping the grey water back into the main sewer (note the outflow pipe leading off in the direction of the wetlands)

During rough grading, our guys excavated a 15’x25’x2′ deep “wetland” area in the middle yard which was to be filled with gravel for treatment of the grey water

Three trenches were then dug in the far back yard, lined with drain rock, and then perforated drain pipe. Check valves in line with the drains prevent siphoning of water back up into the wetlands. These pipes were then covered with a layer of drain rock, and reburied under the soil

The grey water pit was then lined with a protective liner to help keep the EPDM membrane (the water proof liner) from getting punctured. You can buy special material for this commercially, but we reused the spongey plastic separators that came in between the huge paving stones. Rather than throwing it away, it found a second use as our protective liner

An enormous (and astonishingly heavy) pond liner was then rolled out to fill the pit. We are using 40 mil EPDM which is available at specialty pond supply stores or by mail order on-line. It is more durable than the lighter weight PVC pond liner you can buy at Home Depot or Lowes

We partly filled the liner with water to help settle the bottom and smooth it out. Then landscape fabric “socks” were wrapped around perforated pipe which was plumbed to an overflow that passed through the EPDM membrane to flow into the now buried leach field. The pipe coming in from the left with an in-line check valve is the overflow from our rainwater cachement tank, so in a year of very heavy rainfall, our excess rainwater also gets dumped into the greywater leach field

This liner was then filled with (two and a half truck loads!) of  3/8″ pea gravel, and Catherine discovered her little measurement error… the water would overflow the edge of the liner before flowing out of the pipe… the pass through, however, was a nice use of two toilet flanges that bolted face to face through the liner (with a 3″ hole cut in it) making a water tight seal … the guys at our local plumbing supply store know it is usually going to be something weird when Catherine walks in.

The pea gravel was then covered with landscape fabric and a little sand to keep it in place in anticipation of being buried… but things were on hold for yet another trip to the plumbing supply store in search of a solution for that pesky outflow issue…

A little plumbing ingenuity was all it took to bring the outflow pipe down to the right level, have an access point for draining the wetlands (should that ever be necessary), and still keep the grey water from flowing into the rainwater cachement tank…

Now when the water is filled up to the level of the top of the gravel, (but still a couple of inches below the liner top all around!) water starts to flow out of the outlet to the leach field. It is a beautiful thing. Grey water in one end of the wetlands, and cleaned water out the other end off to irrigate the yet-to-be-planted fruit trees

Then all that work is buried under a layer of mulch, and a bit of top soil with only the access drain peeking out.

We had talked about having a grey water wetlands construction party, but this construction ended up being dragged out over such a long time with such uncertain weather, that it really wasn’t practical to try to get a group together (and Catherine was stressed out and quite unpleasant to be around while sorting out the drainage issue).  Our apologies to anyone who had their heart set on shoveling gravel, gluing pipe and schlepping liner.  Should you want to do this yourself, feel free to contact us and come and see our system and see many many more detail photos.

Since “going live” about a week and a half ago, the wetlands have been handling all our grey water, and with the recent deluge, they have absorbed the rain with no problem at all, as it simply flows on out to the leach field.  For those comparing this construction to the original plans, you will notice that the “soil islands” are missing.  These are intended to increase the types of plants that can be planted with their roots down in the water to be treated.  However, we will not be putting in the stream or the ponds for a while yet, and we decided that we would put in just a few plant types initially, and see how it fared through the winter.  We wanted to make sure we didn’t have to do any significant rework of the basic wetlands before adding the other features, (and going to the effort and expense of putting in the stream).  After all, there is still so much to do elsewhere in the house!

Thanks to the guys at Garzac plumbing, the grey water system is now plumbed up and connected. Awaiting only a grey water wetlands to start discharging water into (and, of course, a family living in the house producing grey water!)

The schematic of the grey water system (Grey water schematic) shows what is going on here, but the plumbing ended up being rather complicated as the sewer line from the rear guest house (pipe at the bottom of the picture) comes into the corner, gets joined to the blackwater outlet from the house and discharged to the main sewer line (leaving the picture at the left).

You can see the grey water line exiting the house, and then there is a big diverter valve that lets you divert the water to the sump tank (to the right) or directly into the main sewer at left (if for some reason you are using something in the house you don’t want to go into the grey water system, or if you don’t have your grey water leach fields set up yet!).  The black water sewer line exits the house below the grey water line and discharges directly out to the left.

The grey water comes out of the house too low too be discharged directly into the wetlands, so it needs a BRAC sump pump designed to work with grey water to bring it up to the discharge level (this is NOT ideal – we would have avoided much of this complicated plumbing if we could simply have a gravity discharge, but we couldn’t get it to work with the slopes of the property). The tank is not a holding tank – it is a temporary surge tank.  The pump is sized to be able to keep up with the drains in the house, and discharge water up out of the pipe sticking out of the top of the tank into the wetlands as fast as it comes in.  However, if the pump breaks,  grey water needs to overflow directly into the sewer rather than backing up into the house, so the overflow line with the white check valve on it leads from the tank into the main sewer line (if the main sewer line were ever to back up, the last thing you want is sewage backing up into your grey water system which is why the check valve is there).

The big white pipe along the top is connected to the roof downspouts and leads to the rain water cachement tank in the back yard.  The grey conduit is the main power and the low voltage data lines running to the back guest house.  I wonder if we can get a few more pipes in there somewhere.

The grey water outlet showing the diverter valve, surge tank with top discharge, overflow line with check valve and all the exits to the main sewer at left

The construction of the wetlands will be another big project, and will probably be something we have another construction party for (like the bale raising), so if you missed the bale raising and would like to build some wetlands and a stream later this summer, a general call for volunteers will go out close to the time.  Drop me a line if you would like an invite.  If you were in the bale raising party… you’re already on the invite list ;-)

The view above the stairwell where you can see five paint colors!

As we embarked on painting, I was rapidly running out of time to research what we needed to do with the paint, so this is a bit quick and dirty.  I know that low or no VOC (Volatile Organic Compounds) paint gets you LEED points and “Green Points” and your Boy Scout merit badge for saving the earth, but NOWHERE in all of the info about low and no VOC paints is there any kind of *quantitative* data about how much you don’t emit if you “go low VOC”.   There are many of the same kind of wishy washy relative “this is better than that” statements to be found on the web and in those lazy journalism eco-articles, that made me go beserk about countertops.  Of course the marketing materials of these paint companies assure me that I am saving the world by buying their product, but, can you blame me for being suspicious?  I couldn’t find anything that would let me calculate how much I would save by using low VOC, in numbers that meant anything to me and could give me an idea of relative values.

So I did a back of the envelope calc, and decided to buy zero VOC paints, but this is not as rigorous as I would like it to be, and if there is anyone out there who has done a real analysis of this, I’d love it if you could drop me a note.

First some definitions:

“No VOC” = 5 grams VOC/Liter of paint

“Low VOC” = 20-200 grams VOC/Liter (most eggshell and flat paints that claim “Low VOC” on the label are in the 25 g/L range, but glossy paints tend to be up towards 150 g/L)

“Regular”  (i.e. “interior latex paint”) = 200 grams+/L

NOTE: this is for the base only, and some companies play fast and loose with their claims as the colorants can add significantly to the VOCs in the paint, but these are reasonably good ranges.

Some of the 27 odd gallons of paint we used

Many of the benefits that people ascribe to the low and no VOC paints have to do with indoor air quality, but since 99.9% of the VOCs are gone after the first two weeks of drying – it seems to me that this aspect of the low/no VOC debate only really matters if you are painting a house you are going to be living in at the time of painting, since after the paints are fully dry, a properly vented house would have no discernible difference in air quality.  Given that we aren’t living in the house yet, I discounted the indoor air quality aspect (since painting with the stuff, however, next time I am painting a house that I am living in at the time, I am DEFINITELY using “no VOC” paints, as anecdotally, it made a huge difference in the livability of the space during the two week drying time)

But if I am simply interested in figuring out my effect on the environment, if I use about 100 liters of paint (~27 gallons) of paint inside the house (including primer and extra coats), then using zero VOC paint in the house vs. “regular” saves at least 200g/L*100L = 20 kg of VOCs

From the EPA “Automobile Emissions: An Overview.” Fact Sheet OMS-5. August 1994, my typical commute of two “cold start” car trips a day and my car sitting around evaporating fuel, I produce about 24g of VOC per day from my car (4 g/day from evaporation only if I just let it sit and don’t use it).   So painting the house with “zero VOC” paint is the equivalent of over 800 days of a 1997 automobile’s VOC emissions. (OK, I have a newer car that that, and my running and evaporative emissions are probably much lower, but even if it is half that, I am saving over a year of car emissions)

That was enough for me to make the decision.  Without looking into it further, we went zero VOC, and bought the Benjamin Moore “Natura” paints.  And they were remarkably un-stinky as we painted.

Those warm shimmering hues… Oh! how I love the beauty of wood!  As I feed this addiction – am I contributing to deforestation, environmental degradation and global warming?  Am I evil because I love wood so much?   Should you be asking “So, Catherine, when are you going to stop demolishing the tropical rainforests of the world because you like how they look cut and sanded with a nice clear coat over the top?”

Wood can be sustainable, and it has a very low embodied energy, but buying wood indiscriminately can do a lot of damage to the environment.  More than anything else in this house, wood was destined to be my worst temptation towards ethical downfall (and it isn’t too fun to admit a lapse).  We wanted a lot of beautiful wood, and weren’t sure this could be done without serious compromise of principals.  So did we manage to put so much wood in the house in an environmentally sustainable manner?

Well… yes, and no. We tried, but maybe not hard enough.

FSC Certified Lumber

First the good news.  FSC certified wood is available, and that is the majority of wood that we used in building the house.  The FSC, aka The Forest Stewardship Council is an independent non-governmental certifying body that evaluates and certifies the sustainability of wood products.  Wood grown sustainably is just that – a sustainable resource that is being farmed rather than “mined”, does not include irreplaceable old growth trees, and it works with local growers all around the world to create not only a sound environmental practice, but strong economic base in wood growing areas.

The FSC certified white cedar in the soffit

What’s not to love?   The FSC is the most credible certification system (alternatives like the timber industry-backed Programme for the Endorsement of Forest Certification (PEFC) are around, but they lack a certain independence that seems necessary).  FSC wood usually costs more because it has “Chain of Custody” certification in which the wood is in the custody, from harvest through the saw mill, of certified FSC companies who agree to certain standards, and are regularly audited for compliance.  There are some critics of the FSC system saying that it is too lax in its oversight of some logging operations, and that there is corruption in some areas where loggers can bribe the certifiers, but overall, despite the lapses, it seems to me that when problems are discovered and pointed out to them, they de-certify violators, and the pressure that FSC certification is bringing to bear on the timber industry around the world is a strong positive force.  We specified that all of our framing lumber, soffit wood, plywood and engineered lumber in the house be FSC certified.  Likewise, Kolbe, our window and sliding door manufacturer could provide FSC certified wood for the frames.

But not all woods are available with FSC certification, so we deviated from purity.

Reclaimed Walnut flooring

Our best deviation is using wood which is “salvaged” from old timbers from deconstructed barns, or “reclaimed” from agricultural fruit and nut trees when they are cut down for replanting orchards.  Using wood from these sources is an excellent way to get beautiful wood without contributing to deforestation.  Reclaimed wood is not eligible for FSC certification as there is no logging portion, but as it is not contributing to environmental degradation, it seems just as good and just as “green”.  We decided to put in reclaimed walnut flooring in the upstairs rooms and walnut stair treads from Restoration timber which is an excellent resource for reclaimed wood.

Someone else's cabinets made out of lyptus

The front door in Honduran mahogany

A little bit more of a grey area is the kitchen cabinets which are “lyptus” – a brand-name for a particular type of eucalyptus wood grown and supplied by a company called Fibria.  Lyptus is a fast growing, plantation grown tree which has PEFC certification of sustainability (which seems great until you realize that PEFC is that industry certification system, so maybe not the best choice, but after some belated research, it really does seem like a relatively sustainable wood).

The choice I made that I am the most conflicted about is the Honduran Mahogany doors we had made.  That’s right: Honduran Mahogany.  When I first started looking into wooden doors for the house, I looked at many different species of wood, and stumbled upon a great company on line with beautiful door designs: Mahogany Doors Honduras.

The wine cellar door

I entered into a lengthy email exchange with Gary, the owner in Honduras, about the sustainability of the wood, the process by which they obtained their logs, kiln dried them themselves, fabricated the doors, and then exported them (I’m sure he thinks I’m crazy).  He assured me they exported with CITES certification because they handled everything from the logs to export of the doors.  Great! everything was grand, I ordered the doors, excellent price, great communication, (a bit of delay) , but they finally came and they are BEAUTIFUL – really really beautiful.

But I had probably stopped my research a bit early (once I had the answer I wanted, I will admit, I didn’t look any further).  In my research for the blog entry, I dug a little deeper, and I probably would have been happier not knowing.   CITES is an extremely shortened acronym for “Conference of the Parties to the Convention on International Trade in Endangered Species of Wild Fauna and Flora”.  Yeah, endangered species.  My doors may be certified, but the wood is still an endangered species.  Best spin:  the CITES certification process provides a sustainable local industry to an area that wouldn’t otherwise have a legitimate local economy and might need to resort to poaching and destroy the trees anyway.  More realistic: those trees probably shouldn’t have been cut down, no matter what the certificate says…

If you are curious about the calculations that went into the embodied energy estimate, this spreadsheet contain all the numbers your heart desires: Embodied Energy Calculation.

This is not a polished document. It is the working spreadsheet into which I put all of my calculations on the embodied energy of the house. The first sheet is the house broken down by material or system with the calculation of the total embodied energy for that material. These calcs reference the materials sheet (the third worksheet in the document) and should be fairly understandable. These are all done in kWh rather than the building industry’s standard of BTUs, but coming from the alternative transportation industry, kWh is a number I have a “feel” for.  It can be easily converted to BTUs if that is the way you think (1 kWh = 3413 BTU).

The bottom of the first sheet includes calculations for how much volume of each material is in the house. Many of these formulas are simply long additive lists because they are taken directly from the house plans or on-site measurements. These will be peculiar to the design of our house, and should you be so crazy as to want to analyze an alternate structure with this method, you would need to spend most of your time generating these numbers that would be particular to your structure. You will notice lots of 1.25 fudge factors to account for offcuts, waste, and simple systemic undercounting that tends to happen in a “bottoms up” estimate like this.  Where I use a fudge factor I try to indicate the rationale in a note.

The second sheet is operating energy calculations. It has a lot more than just the operating energy of the house. It also has the paper towel calculations and my flying and other energy use for the year. It has all the numbers you would need to figure out, for example, how far it is OK to drive your car to a farmer’s market for local produce before the trip adds more food miles energy to your food than your local market where all the fruit comes from Chile. (Not that far unless you buy a LOT of produce! Luckily, our farmers’ market is in bicycling distance.) This is also the sheet where you can find the tool to calculate your personal flying energy (yikes!) and has some conversions for using lbs of carbon as your “common currency” for comparisons. It should be said, though, that conversions aren’t necessarily simple multiplication if the energy in your summation comes from sources with widely varying carbon production per kWh. All my calcs get done with Northern California conversion factors, but if your energy comes from coal or hydro or solar, you’ll get very different numbers. If you want to calculate your carbon footprint, there are many better web based calculators out there that are pretty simple to use.

The third sheet is the individual material embodied energy values with a long list of the websites where these numbers were harvested.   The embodied energy of a “raw” material like stone or sand is very location dependent as it is minimally processed, so the shipping costs predominate. Highly processed materials like aluminum or paints or laminated plastics are much less location dependent as the processing energy put into them dwarfs the energy of transportation.  Luckily for the accuracy of the calculations, the low EE materials with the greatest regional variability in their value, are a relatively small portion of the overall EE, and the error generated by using an average value is small compared to the inaccuracies associated with things like estimating how many steel fasteners are in a structure.  (I actually went and counted the hangers and fasteners in typical studs, joists and trusses in the house to make a reasonable estimate, and I could only do that because there was no drywall up yet!)

This whole thing has many sources for error, so small differences between two choices should not be considered significant. What I was really looking for was where materials choices made unexpectedly large or small differences in the overall embodied energy of the house. Without adding it all up, it would have been impossible to really understand the repercussions (or lack thereof) of each choice.

If you find any errors, please do let me know – I will continue to refine the spreadsheet and post corrected versions if any fundamental errors are found.


Exterior View of Strawbale and Window

It has been a long time between blog posts, but there will be a few catchup.  Catherine has been spending her weekends finishing up all the detailing on the straw bale library interior.  We left the exterior finishing to the experts because it has to be waterproof!

Bamboo is tied through the bales to lock them in place, courtesy of “Boa Constructor”.

After the bale raising party, there is still plenty of work to be done before you have a finished bale room.  The walls of rough bales need to be completely locked into place, and to have their surfaces prepped for the final finishes (stucco on the outside, plaster on the inside).

Locking the bales in place to the foundation starts with the “imbalers” or pieces of rebar that were embedded in the foundation onto which the first row of bales were placed.  The sill plates also have 10d nails in them that act like velcro on the underside of the bales.  Between the sill plates,  the bed for the first row of bales also includes a layer of gravel to allow drainage should (heaven forbid!) any water ever get inside the bale wall.  The key to the longevity and structural integrity of a strawbale construction is keeping the water out!


Lots of details on top of the first course of bales

Side view of bale courses

As the walls were built, the bales were notched into the wooden frame, and the corners were locked together with alternating bales at the corners (like brick laying), and then further locked in with large rebar “staples” that were pounded in on each layer.  On the first row of bales, the electrical wiring is also run to electrical boxes for outlets around the room.  Old-school strawbale construction has you pounding rebar pins vertically down through the stack of bales to tie them together, but for in-fill construction, this is difficult because you have a roof in place above your walls.  Instead, the bale walls are locked together with bamboo poles on the inside and outside that are tied through the wall and tightened to make the bale walls monolithic structures.The top row of bales are held in place on the outside wall by an exterior beam that runs around the perimeter of the room.  The top row of bales is then notched and “persuaded” into place against this beam which prevents them from falling out.  These details were all complete on the day of the bale raising, then the process of completing the walls on the interior began.

2×4’s for the bookshelves

Deep windows

The final step for locking the walls in to place, is to use a chainsaw to notch the bales at regular intervals around the interior wall so that vertical 2x4s can be installed to lock the bales in on the inside.  (Standing on a ladder, cutting straw with a chainsaw is fun for about 10 minutes.)  These vertical 2x4s (which visible in the pictures at right with green spray paint on them – all these pictures can be opened to see larger versions) not only help prevent the bale wall from toppling into the room during an earthquake, but they also provide mounting points to help prevent bookshelves from toppling in an earthquake (this is, after all, the library).  In addition, they provide the internal framing for attaching the lath needed for completing the window details.

When finished, straw is tightly packed under the lath

Catherine pounding in straw!

Window and interior wall finishing is a bit more like sculpture than carpentry – that is, if your preferred media are straw and expanded metal lath.  To take the raw end of strawbales, and make them into a smooth firm surface that can be a finished plastered surface, you need to staple metal lath next to the window opening, then bend it around and staple it to the interior 2×4. You then proceed to ram loose straw into this uneven space with improvised tools until you have a nicely finished curved opening to the window that can be plastered, and won’t crack if you then lean against it.  This is especially important in the large window seat!

The window area — ready for plaster

Close-up of the straw packed in

The main interior walls are a bit easier as they are already relatively smooth.  Once you have found and filled in all the little chinks and gaps in the straw at the top of the bales and around the edges, you can attach lath over the entire surface.  There is some interesting constructs like corner keepers to make out of various types of lath.  Several weekends were spent fabricating all the details and installing them with about 2000 staples to keep everything in place.  Now the entire room is finally trued up, nicely finished and has a surface ready for plastering.  Whew!

Close-up of corner

View from the front

Stacks o’ bales

This post is coming a bit after the bale raising for a couple of reasons – one we’ve been crazy busy, and the other is we were very disheartened by the fact that most of our photos of the bale raising are gone in the digital camera equivalent of opening up the back of the camera with film in it.  There was some weird format error on our card, and fewer than 1 in 10 of the photos from the incredibly fun bale raising are still readable…. sigh

We are trying to get photos from some of the other folks who were there, and if we can, we’ll put up a much more extensive set of photos, but until then… we’ll steel ourselves and blog on with the few remaining photos…

Michele, of Boa Constructor shows us how to work the bales

On a fortuitously sunny Saturday November 21st, an intrepid crew of friends and volunteers interested in straw bale construction arrived for our Mohr Family Bale raising.  The plan is to turn the pile of straw bales (not hay!) into a well-built and sturdy walls for our library.  The goal: deep window seats and high insulation value.

Few people there had any straw bale building experience, but Michele Landegger from Boa Constructor, and Dohnyat, the local straw bale expert, soon turned our rag tag band of surgical robot engineers and straw bale enthusiasts into a crack straw bale construction team.   Michele and Dohnyat are shown at right demonstrating how to notch a straw bale so that it could be fit around the vertical post of the moment frame.  This is a technique that we would use over and over as we cut, re-tied, wedged, and stomped those bales into a precision line.

Dhonyat, of Boa Constructor was the super-bale-expert

As with anything, the key is to have the right tools!  We had bale saws which are like very large knives with big smooth serrations.  You slice the straw more than “sawing” like wood.  There are also bale needles which are like enormous sewing machine needles that you use to thread baling twine through to re- tie a bale into a smaller “custom” bale [no pics of the needle, :-(  but a re-tied bale can be seen] and special “reference” 2x4s to check straightness of the walls as they go up.

But, hands down, everyone’s favorite tool is “the persuader” a delicate, high-precision tool for gently moving those bales into position.

Meg, Ely, and David “persuade” a bale

Everyone loved The Persuader

After 8 hours of measuring, marking, cutting, tying, hauling, placing, shoving, kicking, stomping and persuading, we had raised the walls, and an exhausted and straw covered crew opened some beers, started the grill, and kicked back for the first official party of the new house… it was outside, around a fire pit, and we sat on straw bales and ate off paper plates – but it counts!


and congratulations to what Michele called “the best Straw bale crew I’ve ever worked with”

Amy, Andrew, Arjang, Charlotte, David, David, Dean, Dohnyat, Don, Elymarie, Emily, Forrest, Greg, Jerry, Jennifer, John, Meg, Michele, Mike, Nick, Pamela, Paul, Randy, Suzanne, Thomas, Tom

(and to the kids who so nicely played all day in the back and let the mommies and daddies work!)

Paint it Green

WARNING: this is an extremely long and geeky blog posting.  Proceed at your own risk.

Concrete counter


We, like so many others, would like to be good global citizens, which means that we would like to minimize the global impact of building our house.  So we look for environmentally sound choices.  We want to “go green” – Simple!  Just pull up a website on a subject like “choosing a green countertop” and read that this choice has “more” embodied energy in it’s manufacture than that choice, and this one has “more” transportation energy than that one… so the choice is clear isn’t it? You choose the one that is “less” than all the others, and you can buy your countertop material with a clean conscience and self-righteous conviction that you are doing right by the earth.

Tequila Sunrise Caesarstone


But wait a minute… NO ONE says how much more “more” actually is… these sites just recycle the same meaningless, numberless comparisons – no one ever even thinks to put any of these relative numbers incontext or to make any kind of a statement about how much these differences matter.  So yes, ‘this’ is more than ‘that’…. but should I be concerned? or is this a trivial difference?



So what is a geek to do?  Calculate the actual numbers, that’s what! (Don’t worry, there is a comparison chart at the end.)

Some useful numbers should you care to try this at home:

(Average US family numbers)

CO2 production per kWh = 1.37 lbs
Water use per day = 720 gallons

Transportation costs:

shipping: 0.0887 lbs/ton-mile
trucking: 0.3725 lbs/ton-mile
flying (long): 0.4 lbs/passenger mile
flying (short): 0.53 lbs/passenger mile

“Reference” numbers:

40 gal gas = 776 lbs CO2
30 hours air conditioner = 411 lbs CO2
Flight SFO-LAX round trip = 345 lbs CO2

Websites with useful info:

Carbon fund has shipping info
Life comparison cost numbers
Not so useful countertop comparisons

So since it was the countertop internet comparison pablum that really set Catherine off, she decided to look at the “usual suspects” in these green counter top comparisons: Concrete, Stone (like soapstone or granite), Engineered Quartz surfaces (like Caesarstone or Silestone), “Paperstone”, and recycled glass counters like ICEStone or Vetrazzo.

For our house, we will need about 124 square feet of finished countertop when you include every bathroom, bar, and kitchen counter top. At an inch thickness, that calculates out to a little over 1500 lbs of material. WIth off-cuts and waste, that sorta rounds up to a nice even ton (short ton, not metric)

So for Concrete, “embodied energy” (or energy of manufacture) is relatively easy to find, and it comes out to about 240 kWh/ton.  Although the energy isn’t all electric, we’ll convert it all to CO2 as the common currency, and that comes out to 328 lbs CO2 per ton.  Worse if you have to transport it far, but usually you don’t.

Granite and soapstone (and marble and onyx etc) mining in far off Brazil or India is often used as an example of wasteful shipping costs and high transportation energy.  So if we ship a ton of granite or soapstone 10,000 miles by sea, we get 887 lbs CO2 per ton plus 200 lbs or so CO2 for truck transportation at either end – certainly worse than concrete.  Plus mining is non-renewable.

Go to engineered materials like CaesarStone or SileStone, and (far away mined) quartz (94%) is mixed with binders (6%) to make a nice hard any-color-you-want counter top (such as the now justly famous “tequila sunrise” color).  Although some of the content can be recycled, much of the raw material is shipped half way around the world… and it’s mined… so raw material transportation costs start to look a lot like whole stone (although quartz is considerably more abundant than any of the monolithic stones that are quarried for countertops!)  But now you need to put more energy in to make it (couldn’t find out how much), and if you make it in Minnesota (SileStone), you need to truck it to California when you are done making it which takes about 560 lbs CO2 per ton more.  In the US, Caesarstone is made in Van Nuys California which is only 125 lbs CO2 away by truck.  So these start looking like 1447 lbs and 1002 lbs respectively.

So let’s go to paper – nice and renewable.  Couldn’t find the actual numbers of how much energy it took to produce, but Paperstone touted on it’s website that it’s super recycled content of it’s best product with extra special resins countertops SAVED 254 lbs CO2 per slab over conventional paper based countertops with phenol resin…. that is 1026 lbs per ton.  Since we can assume that at best, it is cutting the energy requirements in half (this is a baseless assumption, but I don’t have a better one), I am assuming that the energy costs of even the best paper based counter tops are around 1026 CO2 per ton and the not so good ones are around 2000 lbs CO2 per ton.  Paperstone is in Hoquiam Washington – about 290 lbs of CO2 away

Then you get things like ICE Stone (recycled glass), and Vetrazzo the “original recycled glass countertop”.  These both get high marks for recycled content, IceStone has the first cradle to cradle certification because it is made with mostly recycled materials.  Couldn’t find an embodied energy number, but even if it is zero, to ship it from New Jersey would take 955 lbs CO2.  Vetrazzo which is local (Richmond) got a “green audit” which calculated 193 lbs CO2 per square meter of installed countertop which comes out to 2659 lbs CO2 for our project.  This is probably rather unfair to Vetrazzo, as they are accounting for ALL the CO2 which I suspect my calculations are not, but still it is not zero, or even that low, so they don’t seem much different from the other choices.

[Plus – I just have to add –  these recycled glass materials currently have a bizarre “emperor’s new clothes” chic about them which is causing so many people to overlook how unbelievably garishly ugly they are.  Article after article rhapsodizes about their “gem like” qualities, and they are going into “green” kitchens all over the country.  Unfortunately, I don’t think they are going to be very green if in a few years everyone starts ripping out these ticky-tacky, dated looking counter tops and dumping them in landfills once the fad is over.  Harvest gold and avocado green appliances anyone? I will grant that there are a few types that are nicer than the others, but most of these just make me cringe!]

In the above chart, the first five columns are the range of lbs of CO2 produced by each of the various countertop materials. Note this is a one-time production. If you divide these numbers by the years you will have the countertops, they become fairly small. The yearly range of two other choices you can make (having air conditioning and conventional vs. solar domestic hot water production) are shown for comparison. If you multiply these numbers by the number of years you will live in the house, they get very very big!

So clearly, we could make a difference of about 1000-1500 lbs of CO2 of embodied energy in the one-time choice of countertops, and it looks like concrete might be the way to go (assuming no (somewhat likely) horrible error in my calculations)…  or I could drive all over looking for slabs that have been taken out of other kitchens I could re-use which is much better from a landfill  perspective, but I might produce a good 400 lbs CO2 doing it if I take more than 2 trips to the East Bay to find these slabs.

…but after all this, does it MATTER compared to the other choices we are making in the house?  If you average it out over the life of the countertop, how much of an energy difference is there between these choices?

Not a whole lot as far as I can tell.  What DOES make a big difference is how much energy the house uses or saves on a day to day basis.

For example, if we don’t install air conditioning, and therefore don’t run it for 5 hours a day for three months out of the year, then that is 6165 lbs CO2 a year we aren’t producing.

If we do install solar hot water that covers about 60% of our needs, and displace 117 therms a year of natural gas just in our domestic hot water use, that is 4700 lbs of CO2 a year we don’t produce to heat our water.

So the bottom line conclusion we came to is: choose efficient appliances, conserve water, insulate, insulate, and insulate – and then choose whatever damn countertop material makes you happy – even if it IS Vetrazzo.

Hmmm…. but what about the embodied energy in building an entire house…?  How long does it take to offset  the big energy sink that is all the building materials of a house with the increased efficiency of that house over what was there before…? that will have to be another blog post.