Posts filed under ‘Eco architecture’
Our first-choice heat source at Underhill House is a combination of passive solar and the solar hot water panels that warm our floors and thermal mass interior wall. This dual-solar supply is comfortably providing all the heat we could want during even the coldest days that this not-particularly-cold winter has exposed us to, as well as almost all of the following nights. But the sun does not shine every day.
We have over 20 wooded acres to maintain on our 44 acres of land, and its ecologically-sensitive upkeep will always generate a renewable source of heating fuel. After a tree dies, the carbon it has sequestered will be released whether it decays or burns, so burning a small amount as efficiently as possible seems like a reasonable way for us to supplement our solar sources.
We didn’t really have time to put up firewood this fall while we were in the midst of our building project. Doug and I did take the time last spring to saw up the small branches left on the ground when several oaks that succumbed to Oak Wilt were felled for timbers in the house. We stacked them up on the far end of the drain field where they lay, and now we snow shoe over and grab a few arm fulls every few days. I think we will make it till things brighten up a bit and we can get by on direct solar heat.
We chose a Regency F-1100 stove because our house is small and very well insulated and we don’t need to generate much heat to warm it. Most wood-burning stoves would be overkill for us. Many cast iron stoves and those with soapstone insets are designed to absorb heat from their fires and release it slowly. Masonry stoves are the king of slow release. But we don’t need a slow release stove. Our concrete floors and thermal mass wall can hold and release heat.
What we want from our wood-burning stove is a quick fix to fill in when the sun hasn’t been shining for a few days. That’s why we liked the steel-walled Regency, which passes its heat along to the room as soon as the wood is burning.
We have also learned that Regency plants a tree for every stove sold. That doesn’t seem like a lot – I would rather they plant the equivalent number of trees to provide heat to a small house for a winter – but every little bit helps.
All Regency wood stoves have been certified by the EPA because they have a firebox designed to create airflow around the wood so it burns completely with very little ash or polluting smoke. It is supposed to burn with up to 77% efficiency and meets the DEQ Washington Phase II Clean Air Standard of 4.5 grams/hour or less.
Catalytic versus Noncat
A lot of wood-burning stoves use catalytic converters to get a clean burn. Smoke normally needs to get really hot to combust – about 1100º F. A catalytic converter gets around this by passing smoke through a ceramic honeycomb that burns smoke at about 500-550º F. This gives you the option of burning a long, slow, overnight burn and still combusting the polluting smoke.
Non-catalytic stoves use an air injection method. The draft pulls hot pre-heated air into several tubes running across the top of the fire-box. Each tube has rows of tiny holes. Heated air squirts through these holes, creating jets which fan the smoke into very active, beautiful, secondary flames that hover above the burning logs.
Regency uses this non-catalytic technology. They claim that with durable air tubes and baffles that encourage total combustion and low emissions, the Regency non-catalytic appliances burn cleaner and require less maintenance than stoves with catalytic combustors. The downside is that they don’t work well for an overnight fire, which we don’t need because of our well insulated walls and heat retaining floors.
The EPA has created a consumer information sheet on how to reduce air pollution from residential wood burning. Check it out here.
The timbers that hold up Underhill House were cut from trees on our 44 acres. We were looking for trees that had the right dimensions, interesting forking patterns and were too close to their neighbors or not doing well for other reasons. These “weed” trees made great timbers, but the part we wanted was often 20 or 30 feet in the air atop a rather thicker trunk.
We had a good use for the trunks too.
Later they were moved to a nearby solar kiln for further drying.
Then they were brought home and stored in the barn till we were ready to use them as window trim and sills, bathroom counter tops, kitchen counter tops and a set of shelves for the kitchen. We have oak from trees stricken by oak wilt, some fine elm from an elm tree that was just succumbing, as most elms do by a certain age, to Dutch elm disease. We had some black walnut that was just growing too closely and some amazing cherry from a large tree that forked almost at the ground. A year ago, one side of it went down, tearing away from it’s twin with a disastrous gash. It feels good to salvage pieces like these.
Putting together the elm slabs into counters and shelves has been a particular joy. We decided not to put cabinets on the corner wall because they would cut off the view for people working in the kitchen beside them. Instead, Michael Donovan, one of our carpenters, has shaped some really gorgeous shelves where we will store our plates and bowls and drinking glasses.
How we finished these slabs
We considered several finishes for all the horizontal slab wood in the house. We explored oils and various water soluble finishes and settled on Ceramithane.
Our paint dealer, Phil at Premiere Paint in McFarland, WI, said he used Ceramithane on the counter in his store, where he has been sliding gallons of paint across it for three years, with no ill effect.
It is really neat stuff!
Ceramithane is a water-borne acrylic-urethane finish that cross-links, which is a chemical process that forms a very hard, durable coating. It’s made by Graham Paint, a small company in Chicago. Ceramithane contains ceramic microspheres that turn it into a hard finish. We are also using it on the wood floor in our loft and on our stairs.
It is really bringing out the grain in this cherry slab. It is self-leveling, which means the brush strokes are supposed to wmooth out and disappear. They do, however sets up pretty fast, after which the self-leveling feature no longer functions, so it’s a little tricky to apply, but I spent a very enjoyable weekend finishing our kitchen shelves. That was before Jacob Williamson of Alchemy Painting showed me how to minimize brush strokes more effectively.
Any water-based acrylic will raise the grain in wood, so the makers advise that you wipe the wood first with a damp cloth then let it dry. Sure enough it will feel rougher. Before putting on a coat of Ceramithane, sand the wood lightly till it is smooth again. With each coat, the wood grain will rise a bit more, so each coat needs a light sanding after drying.
We started with 2 coats of the high gloss Ceramithane because that is the hardest form, followed by a coat of satin Ceramithane because we didn’t want such a high sheen. Because that still seemed a bit glossy, we rubbed in gently with fine steel wool.
Then Michael mounted them to the wall, which was also tricky. He used wooden cleats against the back wall and steel rods driven into the timbers to support the bottom shelf and the highest shelf, which will be used to support a stereo speaker.
Those in between are supported by cleats and metal tubes which were actually the same tubes used to cover the wires of our kitchen pendant lighting. We ordered a few moer. We thought they would look good, and they are much stronger than necessary.
On Friday, the shortest day of the year, our solar hot water panels began to pass sun-soaked heat to the floors of Underhill House for the first time. The system awoke to a sunny, cold morning and began to circulate a steadily-warming glycol solution between the panels and our basement storage tank through an underground conduit.
The panels have been in place for a few weeks, but they could not be plumbed to the house until we had a working hot water faucet downstream to facilitate the flushing and filling of the system. A temporary faucet was plumbed into the downstairs bathroom when Gerry Thule stopped by last week to install a hose spigot for the plasterers. Once that was complete, Mark O’Neal from Full Spectrum Solar came out and connected the pipes running between the four 4×10 ft back yard panels and the 160 gallon basement storage tank..
At that point, the panels were ready to produce heat, but they needed one last thing – sunshine. The final installation took place on a dim day with threatening clouds.
The timing was actually a good thing.
Mark said that if they tried to connect the panels on a sunny day, they would be dealing with water so hot it would produce steam in the storage tank. When circumstances dictate a sunny day connection, they have to cover the panels to keep from being burned.
So the panels sat, filled with below freezing fluid, for the next several days as everyone hunkered down for the massive blizzard that swept over Wisconsin Wednesday night and all day Thursday.
Friday dawned sunny with the typical distinct chill and deep, blue sky that follows a winter snow storm, and we were out at the land soon after dawn to get the work area cleared of snow for our gallant crew, who worked on the porch rail in 15 degrees F temps with a serious wind chill.
What was not cold was our solar panels. Doug swept as much snow off them as he could and then we stood back to watch. The snow was soon sliding down the warming panels, and the thermometer that registers the temperature of the fluid as it enters the house began to rise.
Unfortunately, I was taking photos of the winter beauty with a rather low battery, and my camera balked before I could get a shot of the clear, hot, black panels pulling solar energy out of the cold air and piping it to the house.
Until now, Underhill House has been heated by passive solar energy captured from its design and a significant assist from a very efficient propane boiler.
It feels wonderful to be collecting solar heat and storing it in our well-insulated water tank the concrete floors and the thermal mass interior wall for helping to heat our house not only when the sun is shining, but well into the nights and cloudy days that may follow.
Trying to build as greenly as possible means constant decisions.
1. What company to go with?
Then, as we prepared to paint the interior walls of the house, our plasterer, Krome Burke-Scoll pointed out that Hallman Lindsay paints are produced here in Wisconsin, making local paint a possibility. But the closest dealer is in Madison, some 30 miles away. Meanwhile we could get Benjamin Moore paints from a local dealer in Dodgeville, which is only 10 miles from Underhill House.
I decided to go with Hallman Lindsay, which has a good reputation and is manufactured nearby, even though I have to drive a little farther to pick up paint. I try to include paint runs with other nearby errands and keep the miles down as much as possible.
2. How about VOCs?
When you open a can of paint, what are you looking at? What are you about to put on your wall?
That can is full of \
- Pigments – powders that give paint its covering power and its color
- Binders – that hold the powder together
- Solvents – that make the paint liquid when brushed or rolled on, then evaporate leaving a colored film on the surface
It may also contain
- Thickening agents
- Antisettling agents
If it is an oil-based paint, it will use a binder derived from a drying vegetable oil like linseed oil, which sounds harmless, but the oils are diluted with thinners like turpentine, and metallic salts that increase the rate of drying.
If it is a latex paint, the particles are bound together with acrylic or vinyl. Latex paints are durable and pretty color fast and the equipment can be cleaned with water, which makes it seem so much less toxic.
But even latex paints have been a source of VOCs – volatile organic compounds. Pigments and binders can also contain VOCs.
VOCs evaporate into the air and become a menace. They can react with other elements to produce ozone and may cause cancer.
As paint dries, these nasty VOCs are at least 10 times higher than outdoor levels and can be up to 1,000 times higher right after painting. They’ll keep seeping out into the air you breathe for some time. Only about 50 percent is released in the first year.
Paint-related products are one of the worst environmental offenders. They’re the second largest source of VOC emissions into the atmosphere after automobiles, responsible for roughly 11 billion pounds every year, according the U.S. Green Building Council’s Green Home Guide
According to Consumer Reports, Janice Nolen, assistant vice president of the American Lung Association, says studies suggest an increased prevalence of respiratory problems consistent with higher VOC levels in freshly painted homes. “Generally speaking less is always better,” she says.
But, those VOCs were there for a reason. When you remove them, you are removing features you may want in your paint.
The salesperson at Hallman Lindsey assured me that their no VOC paints will perform well on the wall. The difference he warned me about is that the new paints won’t last as long in the can. It can go bad, and he did not hazard a prediction of how long it will keep on the shelf. That’s a little unnerving, but a trade-off I’m willing to make.
We are using low and no-VOC paints in Underhill House. Time will tell if they are as durable on the wall as their more toxic predecessors.
What is your experience with no-VOC paints?
Remember the Beach Boys song In My Room?
Underhill House is as small as we could make it, and that means our bedroom shares one wall with the main living area and bathroom and will share its other inside wall with the television in the den.
The guest bedroom shares a wall with my office and another wall with the stairwell.
Everyone needs a little sanctuary, so we decided to do what we could within the restraints of our floor plan by sound insulating the bedrooms.
This is amazing stuff. It costs more than fiber glass, but there are good reasons to choose it. It’s a better product, and fiberglass is nasty stuff! If you have ever handled fiber glass batting, you know what I’m talking about.
(Here is an interesting youtube about how fiberglass is made. In its favor, it does use recycled glass, but we chose to stay away from fiberglass.
- According to the International Association of Certified Home Inspectors Fiberglass Insulation: History, Hazards and Alternatives – , it has the potential to cause physical harm.
- Small particles that come into contact with skin can lodge in pores and cause itchiness, rashes and irritation.
- When inhaled, particles can cause coughing, nosebleeds, and other respiratory ailments.
- Very fine airborne particles are capable of becoming deeply lodged in the lungs and are believed by many to cause cancer and other serious afflictions.
- OSHA considers this threat to be serious enough that it requires fiberglass insulation to carry a cancer warning label.
- it is generally accepted that, in certain situations, it has the potential to cause physical harm. Small particles that come into contact with skin can lodge in pores and cause itchiness, rashes and irritation. When inhaled, particles can cause coughing, nosebleeds, and other respiratory ailments. Very fine airborne particles are capable of becoming deeply lodged in the lungs and are believed by many to cause cancer and other serious afflictions. OSHA considers this threat to be serious enough that it requires fiberglass insulation to carry a cancer warning label.
On the other hand, the denim insulation is made of recycled jeans, and requires no warning labels.
UltraTouch Denim Insulation:
- contains no chemical irritants and requires no carcinogenic warning labels compared to other traditional insulation products.
- contains no harmful airborne particulates eliminating health concerns regarding particulates in the surrounding environment.
- contains an EPA registered fungal inhibitor to actively resist the growth of mold, fungi and bacteria.
- meets the extremely stringent Environmental Specification 1350 Indoor Air Pollutant testing used for California Public Schools.
- UltraTouch consists almost entirely of natural denim and cotton fibers that are 100% recyclable, reducing landfill waste. By weight, UltraTouch maintains an 80% post-consumer recycled content.
- UltraTouch requires a minimal amount of energy to manufacture aiding the environment with energy conservation and reduction in pollution compared to other types of traditional insulation.
And for our use to make the bedrooms quiet, these fibers offer superior sound deadening properties when compared with fiberglass.
An EPA-registered borate solution makes Ultratouch denim insulation as resistant as fiberglass to mold, fungi, bacteria, pests and fire.
More good news:
Approximately 200 tons of unwanted denim has been saved from the landfill since 2006.
With its Blue to Green initiative, collections of donated denim donates the resultant denim insulation to Habitat for Humanity in regions of the U.S. affected by natural disasters, procuring 662,111 pieces of denim and insulating 1,322 homes so far.
- One pair of jeans makes enough insulation to cover an area about the size of a light switch faceplate.
- 500 pairs will insulate a house
To further insulate certain areas, we added some floor insulation to the walls. There are special products for walls, but they had to be special ordered and cost more.
Roberts AirGuard Premium 3-in-1 Underlayment reduces noise and sound transmission between floors, and is recommended for multi-level construction.
To rate the effectiveness of sound barriers like this underlayment, two standards have been established. STC (Sound Transmission Class) is a measurement that indicates how much noise is stopped by a wall or floor ceiling assembly. (airborne or voice noise). And IIC (Impact Insulation Class) is a measurement that indicates how much impact noise is stopped in a floor/ceiling assembly.
STC and IIC are logarithmic, like the Richter scale. Each 10 points represents a doubling of the noise reduction capacity of an assembly. Walls and floor/ceiling assemblies need to be insulated for airborne sound to achieve a STC of 50 or more. Sound test results for Roberts AirGuard underlayment yield an STC=67 and IIC=68.
So, when all is said and done, I think the Beach Boys would approve.
Underhill House will be hosting an open house
Friday October 26 from 4 to 6 p.m.
3487 County Road H, Ridgeway WI 53582
We’ve made a lot of progress since our last open house when the timbers had just been put in place last July. Unfortunately for the photo, it’s rainy this week. (Fortunately for the ground water, it’s rainy this week – remember July?)
Come check out our hybrid structure now just a few months from completion. We are melding classic building practices like straw bale, plaster stucco and unmilled timbers with cutting edge materials and technology – using local materials where possible - to create a home that will be comfortable, durable and extremely energy efficient.
This is a great chance to learn more about:
Un-milled timber frame construction (see my post Your Next Building Material – Unmilled Branching Timbers )
Straw bale walls (see my post Straw Bales for Underhill House and Where they Came From ) CO2 neutral Caster Oil-based foam insulation (see my post Insulating with Castor Bean Oil is Triple Green)
Passive solar design. See my post How Much Passive Solar Heating Do You Want in a Warming World?
Lime plaster stucco (see my post Why We Chose Lime Plaster Instead of Portland Cement Stucco )
Solar-thermal hot water for both domestic and in-floor heat ( see my post Clark Kent Floor Turns into Superman When It Flexes Its PEX )
We hope to see you there.
According to the Solar Energy Industries Association, properly insulated homes use half the energy of those without insulation.
Underhill House is a blend of old and new ways to insulate.
Over half the house’s walls is insulated with straw bales with an R-value of 30-45.
The other half – that part below ground and the walls that are mostly filled with windows (as well as the roof) - are being insulated with Icynene LD-R-50©spray foam made using environmentally friendly and renewable castor oil with an R value of about 30. (The roof insulation is more like R50.)
Castor oil is a useful substance. According to an Alternative Field Crops manual prepared by the University of Wisconsin and University of Minnesota in 1990, the Egyptians burned it in their lamps more than 4,000 years ago. In the U.S. it has been used as a machine lubricant and has also been used in the making of soaps, nylon, varnishes and paints.
About a million tons of castor beans are grown each year world-wide with India being the top producer. The U.S. is not even among the top ten, so I’m not sure how local our castor bean foam is. The U.S. demand for the crop peaked in the early 1950s when the government subsidized castor bean growers for a short time.
Perhaps we’ll see more fields of castor beans as its use as an insulating foam increases.
3 POWERFUL REASONS TO USE INSULATION MADE FROM CASTOR BEAN OIL:
1. Castor oil insulation is very effective at reducing the levels of carbon dioxide in the atmosphere. According to Ecotec Insulation nearly 3.5 kilograms of CO2 are prevented from entering the atmosphere for every kilogram of castor oil used to make polyol (a main component of LDR50 Insulation) because the polyol was not created from petroleum.
2. Also the castor oil crop is estimated to absorb carbon dioxide from the atmosphere at a rate of 34.6 tons per hectare (about 2.4 acres), with two growing cycles per year. According to a study by the Department of Energy, there are nearly ZERO NET GREENHOUSE EMISSIONS from the production of castor oil and polyol used for LD-R-50©.
3. Substituting a portion of the petroleum based polyol with castor oil creates a renewable material because it can be grown on marginal lands, which are not competitive with food production lands, according to the manufacturers .
Foam insulation also appealed to us because it fills spaces so completely,
Jason and Todd of Kinsler Companies worked for about 6 hours filling the spaces and then trimming off excess foam and cleaning up.
It’s fascinating to watch the process. Jason set up two drums of material that fed in two separate lines into the house. They are mixed in the nozzle just before spraying.
Jason said some companies fill the cavities only partly to avoid having to cut off too much excess when they trim the foam back to the wall studs. But his company fills them completely to make sure the entire cavity is filled.
Like so many attempts to choose the most sustainable option, it’s a trade off.
Yes, there is a bit of wasted foam in the beginning, but the more complete insulation will result in fuel savings for many years. We are trying to build a house that will last for at least several hundred years, so it may well be worth it in the long run to overfill a bit.
Jason said that they used to grind up this scrap foam and blow it into attics, but the process became too costly to justify. Now the excess is landfilled. Sigh. I helped pick up the scraps of foam and managed to reuse some of them to fill several cavities that were not sprayed such as the built out space behind the sofa in the den and a cavity where our bedroom closet fits around a timber. So I felt a little better about the scrap foam.
Bottom line – these thick walls filled with low-density, open-cell spray foam insulation and straw bales should really help keep us warm in winter and not too hot in summer using the least possible fuel.
How are your house insulated?
Are you happy with your R-value?
Are you thinking of improving it?
What types of material do you think are good ones?
The stucco finish on Underhill House has turned into quite a testing ground. The prep work and first coats began in July (See my post Underhill House Gets Plastered part one ).
Finally in October is the end in sight.
It usually doesn’t take so long to stucco a house. Part of the delay came from the fact that the straw bale walls were late in going up. Part of the delay came from a very steep learning curve in lime plastering. Almost all stucco walls in the past hundred years have been made of Portland cement, but we chose to work with lime for some very good reasons. (See my post Why We Chose Lime Plaster instead of Portland Cement .
Part of the purpose of Underhill House is to demonstrate alternative building materials and techniques. We wanted to use lime stucco, a natural material, and we wanted to use local lime. It had to set up very slowly and that involved misting each of the four coats to slow the drying process. During the record heat of July, Doug and I were clambering about on the scaffolding while dragging heavy hoses – sometimes more than once and hour – trying to slow down the drying and cracking that was occurring as the plaster dried.
Still, it was cracking, and when the final coat was mixed and applied, and we misted it — the plaster started to fall off the wall in glops. It was all pretty horrifying. Perhaps most horrifying to Krome Burke-Scoll, who runs Artisan Exteriors, and had agreed to step away from the Portland cement mortar with which he is vastly experienced to try lime plaster with us.
We worked with the local lime and used a product to make it set up faster, but it just didn’t work. PowerPozz turns out to be used as a lubricant in the gun line for spraying Portland cement. As Krome says, “They need something slippery to reduce viscosity when they need to gun up truck after truck after truck of ready mix.
It was locally produced, and it was low cost, but it was not working on our walls.
Back to the drawing board!
After a lot of consultation with East Coast plasterers who have a lot of experience in restoration work, Krome has settled on a different lime plaster.
It seems there is a form of lime that does set up without misting in a reasonable amount of time. It is hard and durable. It comes from France. Sigh.
When balancing all the variables that make a building material sustainable, one that we weight highly is durability. Living in a very cozy little house in the Netherlands that had been providing shelter for over 300 years made me want to build a house of materials that will last, and in this case, that means lime from France.
Krome is dealing with an American supplier, and he asked them not to ship until they had a full truck coming this way. He was told there was a truck of stone coming our way that they could add it to. So I take some consolation in that. We are still using local sand.
Now that the new plaster is in use, things are moving forward again. One of the carpenters told me yesterday that he heard laughter coming from outside on the scaffolding. That’s a good sign. For a while, things were pretty glum out there.
Now we are coming to the fun part – picking the tint. At first we were planning to go with the natural plaster and add no tint. But it goes up very light and then dries lighter, and it just seemed to be jarringly bright.
I would like the whole building to blend into the hill and for the stucco to have a “dialog” with the tans and grays of the stone foundation, and so we are going for adding a little buff tint. The buff tint is also local – mined just south of Galena IL.
Krome tinted the scratch coat so we could get a sense of what kind of color we were talking about. In part of the wall he used a bag of tint. In another part only half a bag and in the next stretch just a quarter bag, and in the next section no tint at all.
Della and I came out Tuesday morning, and Krome and Steve pulled up the plastic tarp so we could all study the effect. We have decided on half a bag. It will warm up the plaster a bit, but leave it light enough to reflect heat in the summer.
After the brutal heat we have just survived this July, I think keeping the house cool in summer will be more of a challenge than keeping it warm in winter.
We are going to get between our two floors on a winder staircase that Della designed. I was going to blog about the wonderful winder stairway at Underhill House today because the basic framing in was completed yesterday.
Winders are nice because they minimize how much space the stairs take up.
Winders are awkward because it’s difficult to move things up and down on them.
Winders are also beautiful to look at and fun traverse as you spin around the corners.
Unfortunately, winders can also be a little tricky, and yesterday I went down them a little fast as it was getting a little dark, and I fell. I caught myself — but yikes and ouch and all of that.
So instead, today I’m providing a round up of some of the more interesting ways to get between floors that I have found.
If you are thinking of getting up there with flare, check out these.
These stairs are both beautiful and minimal. LINK
Here’s a stairway that’s really a ladder that I saw in a Sarah Susanka house in Libertyville IL. I loved the slots. they were great grips! LINK
Having recently fallen on a stairs, I’d like to see a railing here, but I commend them on their use of space. LINK
All the king’s horses and all the king’s men…. Can this space-saving stairway be for real? LINK
This stairs gets first prize in my book. It takes you all the way between floors while only using 1 square meter of space! LINK
What’s your favorite stairway here, or do you have another to share?
Underhill House got a thorough once-over last week.
Scott Godfrey, Director of the Iowa County Office of Planning and Development in Dodgeville, had asked if he and a group of other regional zoning/planning colleagues from surrounding counties, all members of the SW District of the Wisconsin County Code Administrators, could have a tour of Underhill as a part of their quarterly meeting.
Scott said our “unique architecture and construction techniques” would be a “field trip of interest, and expose the planners to an alternative style of construction.”
There was no one available from Whole Trees Construction to lead the tour because they were conducting an off-site retreat that day, so Doug led the tour, and we tried to cram in as much of the innovations and out-of-the-box building practices of Underhill into the tour as we could for Scott, along with Dan Everson of Dane County, Brentt Michalek of Sauk County, Terry Loeffelholz from Grant County, Steve Sorenson from Sauk County and Jeff Krueger of Grant County.
Scott told us later that they shared the experience with the planners who couldn’t make the field trip, but did attend the business meeting…colleagues from Richland, Green, Lafayette and Crawford counties.
Part of the purpose of building Underhill House is to explore and popularize a number of alternative and hopefully more sustainable building materials and methods, so we felt very honored to have so many thoughtful and influential planners taking a close look at our project.
Doug explained how the roof is made. See my post, THE FIRST TEN LAYERS OF OUR SOD ROOF
He told them about how the trusses were made on site (see post THE ROOF FOR UNDERHILL HOUSE IS A MATTER OF ).
He talked about the research Whole Trees has been doing in partnership with the U.S. Forest Products Laboratory on the strength of the branched timbers. That has allowed us to
- Use what would normally be considered weed trees for the structural supports of our house
- Thin the woods, allowing the remaining trees to grow bigger and sequester more carbon while the carbon trapped in our house timbers is held in place, and not released from some slash or burn pile.
- Eliminate the many expenditures of fuel needed to transport, mill and further transport the timbers for our house.
- Employ local craftsmen to peel, smooth and join the timbers into a sturdy frame.
- Last but not least – create the naturally lovely framework of the house that honors the trees and creates a unique living space.
One of the planners asked how we fit the individual pieces together.
That’s an interesting question to answer because it has been a very organic process from last summer when we walked our land with our architect, seeking out trees that would have the right dimensions and those standing too close to a neighbor. Some of the chose ones were succumbing to one of the many perils trees face, like oak wilt, dutch elm disease or lightning strikes. We were also looking for trees whose interaction with their environment had given them a lot of character. Della Hansmann (our architect) and Bryan Dalstrom (our construction manager) had certain kinds of arches and bends in mind.
Once all the trees had their bark peeled last summer while they were still standing, and then felled in the winter and pulled by tractor to the barn yard, Bryan began to study each timber carefully, and we met with Della and him one wintery day when ice crystals had covered everything, to go over how they planned to use the timbers. That was when I first started to see an image of the house in my mind.
The joining process took a great deal of time and craft. The three major bents were joined while lying on the ground where they could be moved about on rolling carts. Many other joints were started before the beams were put in place, but each one took some final carving with angle grinders to make the final smooth, embracing unions.
We talked to the planners about the basic principles of passive solar design that guided the shape, orientation and window placement of Underhill. The rule of thumb is that you want to have
- Most of your glazing on the south wall, and next most on the east wall and incorporate some mass to store the solar heat these windows collect on a winter day. For summer, these windows need to be shaded from the sun, which rides higher in the sky then.
- The north and west walls should have just a few windows because north windows will let in the winter cold, and west windows will amplify the summer heat.
Doug explained about the PEX tubing in the floors and mass wall. See my post, CLARK KENT FLOOR TURNS INTO SUPERMAN WHEN IT FLEXES ITS PEX .
Judging by their questions and attentiveness, the Code Administrators seemed to find what we are doing interesting. I was so excited by their visit that I almost forgot to give them all a scone that I’d baked early that morning. But in addition to the scones, I hope the tour provided some good food for thought. The group has asked for another tour when the house is complete.