Category Archives: Construction Chronology

Nauhaus Prototype Update: We're Done So Quit Askin'!

Thanks to everyone who has pushed me for an update on the carbon neutral prototype house project. I’ve had my hands full and blogging just hasn’t risen to the top of the list. Stay tuned because I have six months of great research results on a number of fronts including compressed earth block floors and walls, site made earthplasters, and a simple purchased clay and sand earth plaster.

What everyone asks first, however, is “when are you gonna be done”? Let’s put that baby to bed once and for all: we’re done. We’ve received our Certificate of Occupancy from the city and are jumping through a few hoops for the bank (don’t get me started, gawd!). Our test family, Jeff/Jeanine/Jackson (JJJ), are moving in upstairs next week. We’re looking for someone to live in the downstairs apartment, and the Nauhaus think tank/office/lab will be moved to the downstairs office.

So from a real estate, taxes, and bank perspective, we’re done. However, the point of this research project wasn’t just to build a house, but to create a living lab and opportunity for study, so there is still lots of work that we’ll do. High on the list will be to complete the final blower door test to see if we will receive Passive House certification. In the next month or two, we’ll be completing a collaboration with Tom Rioux of Earthpaint to test a number of finish solutions for the earthen materials in the building. This is exciting work because in the end we’ll be able to specify commericially available products from Earthpaint to finish and seal compressed earth blocks and earthen plasters.

If you want to help us with our ongoing research, we still need support to realize our:

  • performance monitoring system
  • “urban homestead” landscape installation
  • 7KW photovoltaic system to make the project perhaps one of the first carbon neutral houses in the world
  • — Clarke

    Nauhaus Prototype Gets Plastered

    Exterior and interior plastering is underway on the carbon neutral Nauhaus prototype.

    The interior surface of the hempcrete walls has a base coat of earthen plaster consisting of sub-soil harvested from the construction site and mixed with sand and water. The mix was chosen after testing sixteen different compositions, a process spearheaded by intern Shannon Levenson. Earth plaster serves the Nauhaus prototype mission because it requires almost no energy to make or transport, and therefore has very little carbon emissions associated with it. In addition, earth plastering is fairly easy to learn, requires few tools, and is instantly gratifying, both because it’s beautiful at any skill level and very similar to playing with mud pies, a therapeutic experience that many adults realize they have been neglecting for too long. Whatever the reason, the earth plastering process attracted volunteers and interns like flies to…well, compost.

    The exterior wall surface has been covered with a base coat of lime-based plaster supplied by Lime Technology as part of the hempcrete wall system. Both interior and exterior plasters were applied directly to the hempcrete which proved to be an excellent plaster substrate. Fiberglass mesh, similar to mesh drywall tape, were embedded in plaster over any joints or cracks in the hempcrete. Together these plasters over hempcrete create a vapor permeable wall system, sometimes called a “breathable wall”. The idea is to create a wall that is open to taking on and giving off water vapor in response to humidity levels in the air inside or outside the building.

    We believe vapor permeable walls will last much longer and help create better indoor air quality than cavity wall systems that dominate US residential construction. As any builder will tell you, it’s pretty much impossible to keep water out of walls. Permeable walls are designed with the idea that it’s okay if some water gets in as long as it can get out just as easily and won’t cause any damage in the process.

    We've Got Windows

    A quadruple pane window from Serious installed in a hempcrete wall in the Nauhaus Prototype
    A quadruple pane window from Serious installed in a hempcrete wall in the Nauhaus Prototype

    Well, we finally got the windows and doors installed. Okay, let me vent for a sec: prototypes are a bitch. We had to do a lot of head scratching and trial and error to figure out the best way to insure airtightness in our installation. The hempcrete is awesome, but it create its own set of challenges, especially since our truly wonderful Serious windows aren’t really designed to be installed in the middle of thick walls. (Serious is a partner with us on this project and we’re working with them to make things easier when you decide to replicate what we’re doing.)

    First, let’s sing the praises of these windows. Though a number of German companies make windows in this category, Serious Materials is the only US company that can meet the required specs for a Passive House. All window and door units on the project have fiberglass frames and quadruple pane glazing. Southern glazing has a center of glass insulation value of R-7 with an impressive solar heat gain coefficient (the percentage of solar heat that passes through the glass, 1.0 would be 100%) of about 0.7. This allows for heat gain from the low southern winter sun, a strategy integral to the Passive House integrated design system.

    North, east, and west glazings weigh in at an amazing center of glass rating of R-11, a rating equal to the fiberglass insulation in some conventional stick frame walls! This is compared to R-2 for a typical double pane window found on most US projects. Unlike the heavier European windows, Serious reaches this performance level with two pieces of glass and two pieces of plastic allowing for a thinner profile more like conventional windows typically available in the US.

    Why all the fuss? Well, I’ll tell you. In a Passive House in our climate region, walls need to be about R-40.  Sticking an R-2 hole in an R-40 wall just doesn’t make sense.  In a Passive House, the idea is to spend money on passive elements, extra insulation and really good windows for example, that don’t require energy inputs to do their job once installed, unlike heating, cooling, and ventilation equipment. In the right configuration, these passive elements combine to allow for a much simpler and less expensive mechanical system, thus saving money in construction and afterwards with much lower energy bills.

    Anyway, we’ve got video footage that we’ll eventually compile into a bunch of great educational how-to videos on the ins and outs of all this nifty construction detailing. If anyone out there is getting antsy for the goods, getting us a grant to fund collation of the documentation footage would really speed things up. Until then, wet your chops on these few photos:

    Here you see our custom plastic lumber sill piece with groove for backer rod and space for spray foam, the edge of the bituthane sill pan (green stuff), and the poured in place concrete exterior sill
    Here you see our custom plastic lumber sill piece with groove for backer rod and space for spray foam, the edge of the bituthane sill pan (green stuff), and the poured in place concrete exterior sill.
    All windows had to be pre-drilled through the fiberglass frames...
    All windows had to be pre-drilled through the fiberglass frames...
    ...then screwed to the stud framing in the middle of the hempcrete wall.
    ...then screwed to the stud framing in the middle of the hempcrete wall.
    Jeff installs backer rod as part of a multi-step installation process to insure maximum airtightness
    Jeff puts his engineering degree to work installing a backer rod as part of a multi-step installation process to insure maximum airtightness
    The plastic lumber sills were filled with foam after installation through a series of pre-drilled holes...ingenious!
    The plastic lumber sills were filled with foam after installation through a series of pre-drilled holes...ingenious!
    Southwest view showing all the windows installed. Doesn't look like any big deal, does it?
    Southwest view showing windows installed. Doesn't look like any big deal, does it?
    Installing the doors was a whole different story...don't get me started!
    Master carpenter and benevolent genius Tim working on a door. Installing the doors was a whole different story...don't get me started!

    Hempcrete Nau

    Jen, who has been doing these construction updates, decided to go back to school for some reason….she had some lame excuse about needing to make money to buy food or something… whatevs!

    Anyway, we’re behind on the blogging and I surely don’t have time to bring things up to date right this minute. The quick synopsis is that the hempcrete installation is complete (yeah, baby!) and we’re moving into “Phase II” of the build in which the design team will be on site a lot more working with interns. Right now we have four great interns, Christopher, Shannon, Francoise, and Bertrand. (Fun fact: F&B rode their bikes from Montreal by way of Florida and Texas!? Those crazy Canucks.)

    Here are a few picks. I hope to get more up soon….or convince Jen to quit school.

    Southwest view of finished hempcrete installation. A lot of people comment on how much it looks like rammed earth.
    Southwest view of finished hempcrete installation. Looks a lot like rammed earth, eh?
    shanon_bertrand_christopher
    Shannon, Bertrand, and Christopher.
    Francois working on a mortise and tenon roof bracket
    Francois working on a mortise and tenon roof bracket.
    Tim teaching joinery as part of bracket production.
    Tim teaching joinery as part of bracket production.
    tim_bert_porch
    Tim and Bertrand installing the front porch deck framing.
    shannon_plaster
    Shannon working on the earth plaster test wall.
    Jeff raises a window header in a hempcrete wall... it's easier than it sounds.
    Jeff raising a window header in a hempcrete wall... it's easier than it sounds.
    Jeff starts air tight installation of a window frame.
    Jeff starting air tight installation of a window frame.
    Christopher predrills a window frame
    Christopher predrilling a window frame.
    Tim gives a tour to a class from Warren Wilson College.
    Tim giving a tour to a class from Warren Wilson College.
    bert_wood
    Bert dreaming of poutine.

    Nauhaus Prototype Project Commercial

    The weather has slowed down construction onsite, so for your infotainment, here is a short video about the project, created by Nauhaus comrade Jennifer, for a class at UNC Asheville.

    Click here to view the entire Nauhaus Prototype Construction Chronology.

    If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.

    Nauhaus Prototype Project from jennifer bennett on Vimeo.

    The Latest in Prototype News

    For the last couple weeks, Matt and his crew, plus volunteers, have been continuing the second floor Hemcrete installation.

    If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.

    Click here to view the entire Nauhaus Prototype Construction Chronology.

    Current View of Southeast
    Current View of Southeast
    Current View of Southwest
    Current View of Southwest
    Hemp Stacked and Waiting
    Hemp Stacked and Waiting
    The Trusty Mixer
    The Trusty Mixer

    Ben is the fastest Hemcrete installer in the West!
    Adam is the fastest Hemcrete installer in the West!
    Support for the upper forms on the North side.  The black landscape fabric covers the CMU blocks, which will be beneath grade.
    Support for Upper Forms over CMU Wall
    Closeup of Form Attachment
    Closeup of Form Attachment
    Scaffolding
    Scaffolding
    The forms are built up almost ot the overhangs, and are stuffed by hand.
    The forms are built up almost ot the overhangs, and are stuffed by hand.

    Completed Window Opening
    Completed Window Opening

    Thermally broken mounting bracket for roof supports.  The pink is foam insulation.
    Thermally broken mounting bracket for roof supports. The pink is foam insulation.

    Closeup of Hemcrete in Form
    Closeup of Hemcrete in Form

    A combination of custom and pre-made forms is used on the 2nd floor.
    A combination of custom and pre-made forms is used on the 2nd floor.

    This Week in Prototype News

    The big blizzard of ’09 temporarily put the kibosh on construction, but we’re back up and running.  The Hemcrete forms have come off of the first floor, Serious Materials windows have arrived, and the roof is moving forward, with horse drawn, local, sustainably harvested hemlock fascia boards from Mountain Works installed this week.

    If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.

    Click here to view the entire Nauhaus Prototype Construction Chronology.

    Wall with Custom Hemcrete Forms
    Wall with Custom Hemcrete Forms
    Wall after Hemcrete Forms are Removed
    Wall after Hemcrete Forms are Removed
    Serious Materials Windows Have Arrived
    Serious Materials Windows Have Arrived
    Serious Materials Windows Waiting for Installation
    Serious Materials Windows Waiting for Installation
    Head and Jamb of Hemcrete Window Opening
    Head and Jamb of Hemcrete Window Opening
    Jamb and Sill of Hemcrete Window Opening
    Jamb and Sill of Hemcrete Window Opening

    Sustainably Harvested Hemlock Fascia
    Sustainably Harvested Hemlock Fascia

    Closeup of Future Patio Connection at West Wall
    Closeup of Future Patio Connection at West Wall
    Nauhaus Prototype as of December 31, 2009
    Nauhaus Prototype as of December 31, 2009

    Hemcrete Installation Continues/ Mountain Works Stops By

    The Hemcrete installation continued today in the freezing weather, and is up to the second floor.  Ian Snider from Mountain Works dropped by yesterday to discuss some of the sustainably harvested wood he will be supplying to the project. Ian’s company uses horses to remove the trees that they selectively cull as part of a forest stewardship process.

    If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.

    Click here to view the entire Nauhaus Prototype Construction Chronology.

    Ian Snyder and Jeff Buscher
    Ian Snider and Jeff Buscher


    House with forms on the South side.
    House with forms on the South side.
    elisha measures
    Elisha measures.
    Shutter being attached.
    Shutter being attached.
    elisha
    Elisha
    Sarah tamps the Hemcrete.
    Sarah tamps the Hemcrete.


    mixing
    Hemcrete in Mixer
    madera-mixing
    Nauhaus Building Systems mixes Hemcrete.
    interior forms
    Shutters line the interior South wall.
    Interior of South and West Hemcrete walls with no forms.
    Interior of West and North walls without forms.
    Electrical Box in Hemcrete
    Electrical Box in Hemcrete


    Hemcrete Installation/ LEED Consultation

    Yesterday, the full-on Hemcrete installation was started.  Thanks to the volunteers who continue to come out and shovel hemp in this wet, cold weather!  If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.

    Click here to view the entire Nauhaus Prototype Construction Chronology.

    Bucket of Hemp
    Buckets of Hemp

    Custom forms were built out of plywood to supplement the plastic shutters provided by Lime Technology.
    Custom forms on Completed Framing
    Exterior Bracing at Plywood Forms
    Exterior Bracing at Plywood Forms
    Custom window forms were built so that the jambs could flare out and let in more light.
    Custom window forms were built so that the jambs could flare out and let in more light.
    Horizontal form supports are painted orange, as they will be removed after the the Hemcrete is packed in.
    Horizontal form supports are painted orange, as they will be removed after the the Hemcrete is packed in.

    Matt pours hemp into the mixer.
    Matt pours hemp into the mixer.
    Nauhaus Team and Volunteers Installing Hemcrete
    Nauhaus Team and Volunteers Installing Hemcrete
    A volunteer tamps down Hemcrete around the studs to ensure a tight seal.
    A volunteer tamps down Hemcrete around the studs to ensure a tight seal.
    Sarah Brinker tamps Hemcrete.  At this point, the forms are 4' high because the first lift is completed.
    Sarah tamps Hemcrete. At this point, the forms are 4' high because the first 2' layer is completed.

    Today, as the Hemcrete installation continued, Amy Musser of Vandemusser Design came out to give us a LEED consultation.  The Prototype is still on track to receive LEED Platinum certification.

    Amy Musser, Luly Gonzalez and Chris Cashman discuss LEED.
    Amy Musser, Luly Gonzalez and Chris Cashman discuss LEED.