Read the article here. One of the highlights is you’ll find pictures of the illusive Jeff Buscher doing things like faking reading a newspaper. For these and other priceless shots, go to “Related Links” and click on “Home of the week: Buscher”.
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:
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,” says Clarke Snell of the Nauhaus Institute. “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.”
The Nauhaus Prototype project hit a milestone this month with the installation of doors and windows form Serious Materials. The project hasbeen designed to reach the Passive House Standard and therefore requires extremely high performance 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. 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.o 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.
“In a Passive House in our climate region, walls need to be about R-40. You just can’t stick an R-2 hole in an R-40 wall,” says Clarke Snell of the Nauhaus Institute. “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.”
.…okay, not really a press release, just a feed from our blog. Hey, we’re a small, busy, underfunded R&D organization. What do you want from us?
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.
Here’s a rockin’ ad for the Nauhaus prototype put together by our own Jennifer Bennett.
If you’re interested in volunteering for the Nauhaus Prototype Project, please contact Billy.
Press Release: Crazy Winter Makes Hemcrete Installation Interesting, Serious Materials Windows ArriveThursday, December 31st, 2009 by mandible
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.
Tradical®Hemcrete® is an insulation material made from industrial hemp chips (shiv) in a lime-based binder. We are VERY excited about helping to introduce this wonderful material to the US housing market. As a design group that comes out of the world of low-embodied energy materials (often called “natural building”), we have been in a quandry as to how to acheive the highest energy performance and durability in a wet, humid climate while staying true to our “natural building” roots. We love vapor permeable wall systems like cob and adobe, but don’t like the low insulation values. We like straw bales, but find them impractical in our wet climate, as well as finding their clunky, bulky form difficult to work with practically. Our favorite “natural” wall material is clay-slip straw, but find a number of practical difficulties in working with the material in the field. We think that materials like Hemcrete are a great fit for practical, high-performance, low-embodied energy building systems like ours, the Nauhaus.
Tradical®Hemcrete® is manufactured by the UK company Lime Technologies, LTD and distributed on the east coast by Hemp Technologies, LLC in Asheville, NC. Though we understand the inherent unsustainability of shipping a bulky building material from England, we have chosen Hemcrete as part of a long-term commitment to find and promote the best building materials for sustainable design. It is our belief that it is time to advocate for the production of industrial hemp products in the United States.
Okay, let’s get the “pot” jokes out to the way. Industrial hemp doesn’t have the drug properties of its cousin, marijuana…so don’t smoke it, Holmes. Hemp used to be a mainstay of the US economy. There was a time when you HAD to grow it if you had a certain amount of land. It grows quickly, is a nitrogen fixer, and is the source of a huge variety of useful products including fabrics, oils, ropes, and a variety of building and automobile related products. US consumers purchase more hemp-based products than anyone else in the world, but it is currently almost impossible to grow industrial hemp in this country. Clearly this makes no sense. In the US our friends at Hemp Technologies, and our suppliers of Tradical®Hemcrete® are hard at working changing this. They are lobbying policy makers to change regulations and are planning to manufacture Tradical®Hemcrete® in the coming years. Hemp Technologies is also a partner with us on the Nauhaus prototype project.
To learn more about industrial hemp and everything Hemp Technologies is doing, visit their website: www.hemtecusa.com
To learn more about why we’ve chosen Tradical®Hemcrete®, read this.
Passive House certification is perhaps the most rigorous and thorough building energy performance standard in the world. Though thousands of buildings have been built to this standard in Europe, there are less than 10 certified Passive House buildings in the US. We have designed the Nauhaus prototype to Passive House standards and are in the process of seeking certification.
Okay, yes, it’s a major hassle. Why do it? Oh, let me count the ways:
1. Climate Change. Unless all the climate science eggheads are oxygen starved from too much time in high altitude weather balloons, it seems clear that we need to drastically cut climate change linked carbon emissions to prevent a climate change rollercoaster that we will be helpless to control. Since our buildings are responsible for 50% of our carbon footprint, the best approach would be to make them carbon neutral, in other words, design, build, and run them so that they are responsible for no carbon emissions. Since carbon is emitted through combustion of fossil fuels, the best thing to do would be to burn no fuels to heat, cool, or power a house. The only way to do that is to drastically reduce building energy requirements so that expensive “clean” renewable energy (solar electric, wind, and hydro) systems can be made small enough to be affordable. The Passive House approach reduces heating and cooling loads in our climate by 90% and overall energy requirements by 70%. With this level of performance, carbon neutrality comes within reach.
2. Indoor Air Quality. Since most buildings loose heat quickly through their envelope (exterior walls, floor, and roof), heating equipment needs to warm air to high temperatures to make up for this quick loss. Often, this means that the air is heated to a temperature that will burn dust. Do you want to breathe burnt dust? I don’t. In a Passive House, we dont’ need much heat, so we don’t need to burn dust to create comfortable temperatures. This fact in combination with air-tight construction and very efficient energy recovery ventilation allows a Passive House to create the best indoor air you’ll ever experience.
3. Money. Okay, enough flowery stuff about saving the world and breathing better. What’s the cost? Yes, a Passive House will cost more up front, but that’s the price for the speculator, flipper, and sub-prime mortgage weilding sleeze ball. If you actually intend to live there, you know make it a home, then the cost equation is more complicated. Since Passive Houses cost almost nothing to run and make renewable energy much cheaper by reducing system size, they are without a doubt less expensive for the owner. Save all of your “What’s the payback period” and “How much more do they cost up front” questions for the time being. We don’t know because we are designing our first Passive House now. There’s a lot of info out there on costs, but it is all tied to the European market so we can’t draw clear conclusions from it. Those people eat Bratwurst and have health care for god’s sake! It’s like a whole different planet. Rest assured that cost is of paramount concern for us, so we’ll keep you posted.
Plans for permitting have been submitted for our prototype project, slated to start construction late this spring. We’ve been working on developing a practical approach to carbon neutral, healthy built residential construction for several years. The result is a building system, for lack of a better word, that we’ve dubbed “The Nauhaus” (pronounced “now house”). Though we’ve designed a number of projects in the interim, this is our “prototype” because it is the first to combine all aspects of the Nauhaus vision: the highest possible level of energy efficiency, low-embodied energy non-toxic (“natural”) materials, impeccable indoor air quality, sustainable water management, indoor and outdoor living, urban infill, on-site energy production, and an abundant edible landscape brought together to create a model of urban sustainability. In addition, this project will provide valuable data for others in the green building movement because we will performance monitor the home for several years to compare theoretical to actual performance.