April 2012
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Month April 2012

Entries 5 Total

Hemp Bio-Masonry Building Materials: Under the Microscope

Apr 23, ’12 1:26 PM

The University of Manitoba, Bio-Systems Engineering Department has been testing hemp building materials for the past year. Masters student Jeremy Pinkos, under the guidance of Professor Kris Dick, has been examining different types of hemp-lime walls and assessing their insulative properties, airtightness, density, hygroscopicity, moisture resistance and structural properties. The research is being carried out at the U of M’s Alternative Village, a unique outdoor laboratory dedicated to research, testing, and training related to renewable energy technologies and building envelope systems in Canada. (The Village also happens to be home to one of the largest straw-bale buildings in Canada as well.)

Biostruct has begun testing our material at the U of M this year. Of course, the testing of hemp building materials is nothing new; in Europe, the industry has been growing for over 15 years, and many products have already received third-party certification there. While it’s true that hemp building materials are fairly new to the North American market, there are a few owner-built homes throughout Canada. There are also some houses in North Carolina that have been constructed using imported European hemp and lime materials.

As a building material, hemp-lime has many favourable attributes that are especially valuable in today’s greener building marketplace.

Hemp bio-masonry walls are:

–Fire- and insect-resistant.

–Non-brittle: Since the material lacks the brittleness of cement, it eliminates the need for expansion joints.

–Insulating: Values equal or surpass those of conventional products (R-value of over 2.5 per inch).

–Hygroscopic (vapor permeable, while being impermeable to liquid water): Just as our bodies need to “breathe” by releasing moisture and toxins through our skin, our homes–and more particularly, the walls of our homes–should also be able to transmit water vapour.

Most of the houses being built today are completely sealed with vapour barriers in order to prevent moisture transfer. However, water often finds a way to get inside those seals – by capillary action, for example. And since moisture that enters a sealed wall has nowhere to go, the result is mold, decay and rot. In the case of hemp bio-masonry, the solid mass construction eliminates the air gaps that can lower R-value, even as the material itself facilitates moisture transfer. This breathability is what prevents the buildup of mold and mildew inside the structure.

There are a few fairly common misconceptions about hemp-lime. Some blogs or internet sites claim that “hempcrete” (as they refer to it) is 7 to 10 times stronger than concrete, when in fact, the compressive strength of hemp-lime walls is quite low. This is due to the fact that the product has been designed to be a non-loadbearing, insulating bio-masonry material. (Some people have used hemp to reinforce concrete, which could increase the concrete’s strength, but this is not usually the case with hemp wall systems.) Some of the misunderstandings might be due to the fact that the word “hempcrete” suggests a hemp-reinforced concrete. To avoid such confusion, Biostruct as a company has avoided using that name; we prefer to use the more accurate terms “hemp-lime construction” and “hemp bio-masonry materials”.

Hemp-lime walls use what natural building expert George Swanson calls “living cements”, meaning they bind well with plant cellulose. Examples include high calcium lime and magnesium oxide. The more commonly used alternative, Portland cement, actually repels cellulose, and must therefore be combined with plastic binders to permit adherence to building substrates. In turn, these petroleum-based binders make the concrete more hydrophilic, locking in moisture and thereby increasing the risk of mold and mildew formation. Another built-in advantage of natural lime, making it a more attractive option than concrete in this case, relates to its curing cycle. As the hemp-lime in a building reverts back to limestone, it sequesters CO2 from the air, thus rendering the structure virtually carbon-neutral. On the other hand, the production of Portland cement requires a much more energy intensive process, and the final product does not provide the added benefit of re-absorbing the CO2 that was previously released.

Agricultural hemp, which is capable of sequestering over 10 tonnes of carbon dioxide per acre, is considered one of the most economical crops a farmer can grow. Moreover, since most of the hemp currently grown in Canada is used in food production, hemp builders needing fibre can make use of an already available by-product. Until recently, the market for Canadian hemp fibre products has been limited, due in part to the lack of secondary processing facilities. Now that the industry is taking off, however, the hemp fibre that was originally being burned or used as animal bedding can be used to create multiple useful products.

Access to new technologies and instruments–for example, life-cycle assessments or LCAs–are revealing both the benefits and drawbacks of various “advances” in green building (including the dawning use of nano-materials, which we discussed previously) and are thus helping to establish the legitimacy of these innovations–or lack thereof. At the same time, municipalities are increasingly taking into account the amount of carbon that is embodied in the structures they build. The desirable features of hemp-lime building systems–in particular, their relatively small carbon footprint in comparison to that of other systems–are bound to get them noticed. We at Biostruct believe they are destined to take a starring role in the future of building.

THE FUTURE OF HEMP BUILDING: IT’S TIME TO START BUILDING BETTER

Stay tuned for more details on the work being done at the University of Manitoba on hemp building materials. Updates will soon be provided as well on the prefab hemp wall systems we are developing in cooperation with SAIT Polytechnic in Alberta. Any parties/post-secondary institutions that are interested in partnering with us in building (as well as testing) some structures in B.C. are invited to contact us.

(Photos: Top two photos courtesy of Erik Eising)

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Are we Trapped in the Psychology of Previous Investment?

Apr 16, ’12 1:23 PM

The ‘psychology of previous investment’ is a term coined by urban design critic James Howard Kunstler (author of “The Geography of Nowhere”, “World Made By Hand”) to describe society’s reluctance to abandon technologies and design standards linked to the vast infrastructure into which it it has already invested heavily (i.e. the retrospective “sunk costs” of our urban/suburban lifestyle)—even though propping up this infrastructure is, at the same time, contributing to various modern crises. Green visionary and architect Sym Van Der Ryn has similarly described how the environmental crisis is largely a design crisis—i.e. a consequence of “how things are made, buildings are constructed and landscapes used.” He notes that “Design manifests culture, and culture rests firmly on the foundation of what we believe to be true about the world.”

As we’ve observed in previous blogs, many of the original models for our Western development and design systems can be traced back to the first Industrial Revolution. The scientific, mathematical and philosophical contributions helped foster the development of methods and goals for science that involved mechanization, the domination and control of nature, linear progress, hierarchical dualities and reductionism. These Newtonian-Baconian-Cartesian notions have been extremely influential in a number of other areas. But what we are now seeing is that many of the assumptions upon which they were founded don’t tell the whole story—and may, in fact, be false. John F. Kennedy once said “The great enemy of the truth is very often not the lie – deliberate, contrived and dishonest, but the myth, persistent, persuasive, and unrealistic.” It seems we may be finally waking up to the truth of those words.

The growing interest in holistic design practices, such as those exemplified in Biomimicry, Cradle to Cradle, Living Buildings and Permaculture, is a source of hope for many. New companies with the intention of solving ecological problems through good holistic design have been sprouting up all over the planet. In a recent interview for Forbes, green chemist and author Dr. Paul Anastas, said “Now we recognize the power and potential of creative design, rather than believing the old myth of a trade-off between environment, health, and economics.” Yet, facilitating a change in the way society does its business, based on such ideas, continues to be a challenge, particularly in terms of market acceptance and affordability. Many of us have grown used to the old, destructive products and practices, and find it hard to abandon them. Even in the case of something as simple as growing a permaculture garden (at our residences or in a garden plot), we often don’t want to bother, mainly because we feel we don’t have time to nurture it properly. In view of the prevalence of dual-income families and the fact that today’s jobs often entail longer workdays, this procrastinating is understandable. Even though we know a better, more meaningful life is possible (and may even wish for it), it seems easier to support the old ways. And, of course, it’s usually cheaper.

Or is it? One thing we forget, is that our global economy has largely been designed around the externalization of social and environmental costs. More and more local economies are being sacrificed on the altar of large, multi-national corporate-driven global supply chains that depend on ever-increasing growth, and accept no responsibility for protecting or contributing to the well-being of any particular community. As a result, members of these communities are feeling increasingly alienated from the “hands” that sustain them; they no longer feel connected to the source of most of the goods and services they use. Yet it is at the local level (to a greater or lesser degree) that society must deal with the costs these mega-companies are externalizing. And as we all know, when a deferred bill comes due, it inevitably has a massive amount of “interest” tacked on!

Author and entrepreneur Paul Hawken likes to say, “We are stealing the future, selling it in the present and calling it GDP.” This, of course, is not the natural order of things; it is, rather, a symptom of poor design. Increasingly, we’ve had to learn the hard way—from various disasters involving environmental contamination and/or the toxic effects of industry on human and animal health etc.—just how expensive it can be to ignore the issue of hidden costs. Isn’t it high time, then, to demand that these multi-national conglomerates stop distorting our supposed “free market” system? –To mandate the institution of “full-cost accounting” that would force such companies to internalize all costs associated with getting their products to market? And isn’t it high time, as well, that we found a broader, more realistic measurement of progress than GDP?

It’s not hard to see, as we look around the world, that the global economy is failing us. Governments are responding to their financial problems with harsh austerity measures, including ruthless slashing of environmental budgets. But is now the time to turn our backs on the vision of a sustainable future—a vision that has only recently come into clear focus? Many—including those involved in green business—would respond with an emphatic “no”! We must do away with the false duality of economy vs. environment. We can, if we so choose, chart a new course towards a more promising future: the tools that would allow us to navigate it are ready and waiting. One leg of the journey may involve transitioning to a restoration economy—one, that rehabilitates ecosystems while fostering innovation and putting thousands of unemployed people back to work. (Are not these people at least as deserving of a bailout as some too-big-to-fail bank?) We may also need to restructure our current monetary system. It is, after all, a human invention. If it’s not working, we can re-invent it. Instead of allowing our dollars to function as “chips” in complex games of speculation and manipulation played out on giant stock exchanges around the world—where they produce what economist David Korten calls “phantom wealth” (basically–funny money), we can steer them back into their original function of generating—and facilitating the exchange—of “real wealth” to build natural capital in society. It’s estimated that Americans alone have close to $30 trillion dollars invested in securities. Imagine what would happen if even half of that ($15 trillion) went from Wall Street to Main Street? What it could do in communities.

Sadly, many people are still stuck in the psychology of previous investment. There’s simply too much money tied up in the models and systems of the past, they may protest. If that’s the case, then we may need to ask ourselves whether humanity itself is “too big to fail.” Of one thing we can be sure: the planet we live on is not about to bail us out—and soon it will leave us with no choice but to change. After all as James Howard Kunstler has also pointed out, modern civilization was built around the premise of infinite cheap energy—and especially, of cheap oil. But the supply of “black gold” is, in fact, finite, and its price—over the long term—is only going to rise. The $147-a-barrel price tag oil carried in the summer of 2008 represented a pivotal point: the point of peak globalization. Wall Street games aside, if subsidies were taken away and oil companies were required to internalize the social and environmental costs of what they do, the price of their product would soon hit that pivotal point again.

We have a lot of work to do, and there’s no reason to wait: the off-the-shelf technology we need to solve these interrelated social, environmental and economic problems is already available. Now is the time we must break through the psychology of previous investment. Let the work begin.

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Green Building: Evolving Towards Affordability?

Apr 9, ’12 9:43 AM
A recent Yahoo!-commissioned survey about society’s evolving view of housing provides interesting insight into a market trend many in the industry are starting to confirm. According to the survey, energy efficiency is a top requirement of what many people envision as their “dream home”–energy efficiency was cited as a desirable attribute more frequently than any other feature. Green building is in fact projected to grow 5-fold by 2016, largely driven by higher energy prices and rising global awareness of resource depletion, climate change, and other environmental concerns.
At the same time, those in the industry are increasingly recognizing their responsibility—and their power—to address such concerns. While buildings use a lot of energy (40 per cent of the world’s total consumption, according to a 2005 study done by the International Energy Agency), they also offer great potential for drastic reductions in energy usage. A 2009 report by KPMG LLP (Canadian division of the KPMG professional services network) estimates that “with proven and commercially available technologies, the energy consumption in both new and old buildings can be cut by 30 to 50 per cent, while producing a favourable return on the initial investments.”
Most measures that reduce greenhouse gas emissions from buildings also result in reduced energy costs over a building’s life cycle; this means that the higher initial costs are eventually offset. Still, architectural firms that are committed to “pushing the envelope” on green features often find themselves embroiled in bureaucratic battles they didn’t bargain for. And when difficulties in getting a particular design element approved result in lengthy project delays, developers may find themselves in the unenviable position of having to absorb costs that would normally be passed on to the purchaser.
The fact is, green building on its own does not go far enough; if a sustainable housing industry is to thrive, companies and governments must increasingly take a triple-bottom line approach that measures success not only in economic terms but also in relation to social and ecological factors. And since, as we’ve already noted, a green structure can (initially) be more expensive, more needs to be done to address affordability. This is particularly true in areas like Vancouver, where land prices have soared in recent years; potential and current homeowners shouldn’t have to choose between their pocketbooks and the planet.
When it comes to designing a green building, the ability to take passive advantage of free energies—like natural lighting, heat, and ventilation—is an important part of bringing down costs. Of course, “active” technologies (such as solar PV panels) can still be incorporated as well, but a good architectural principle is to begin by ensuring any available energy is utilized as efficiently as possible. Accordingly, a building should be oriented towards “solar south,” if possible, in order to take advantage of the free energy shining through its windows during the day. Provided the structure incorporates materials with a decent thermal mass (such as exposed concrete or earthen floors), these can then help to store that heat long after the sun has gone down for the day.
The types of materials used in the building are thus an important consideration. Utilizing products that buffer humidity and are vapour-permeable reduces the necessity for expensive mechanical systems that can quickly drive up the overall price of a green building. Not all building codes are favourable to such approaches, however. –Yet! This is why it’s very important to work with the right team. There’s no point in reinventing the wheel; in many situations, the work of training inspectors and government officials in green techniques and technologies has already been done. If a precedent has been set in one community (or with one home), it will likely be a lot easier to get a new project approved. A speedy approval process, as developers will be quick to tell you, can dramatically decrease the cost of a green project.
One material that has good thermal insulation, moderate thermal mass, and excellent vapour-permeability is hemp bio-masonry. In the UK, where hemp building materials have been in use for some time, various affordable housing projects have taken advantage of the many ways in which these products help to
reduce the cost of green building. Hemp materials carry a significant R-value per inch, so—in comparison to what is required when other natural building materials (such as cob or rammed earth) are used—wall thickness can in turn be reduced. This is very important in urban areas, where land prices are higher.
Completing green projects in today’s business environment is often a “labour of love.” You don’t do it for any other reason than the future of your kids,” one local builder is quoted as saying in a recent Globe and Mail article. “(But) in the process you bankrupt yourself—so your kids don’t have a future.
The builder was probably only half-joking (unfortunately)! But things are changing. On the “system reform” side of the equation, bringing in better appraisal techniques and making energy use more visible are crucial to promoting public understanding and acceptance of more efficient technologies. The result will be further reductions in associated costs; thus, there is good reason to expect that in the near future, not only will green homes be more affordable, but the business of building green—for the sake of our children and their future—will also be a lot less challenging.

 

One excellent example of an affordable green building project is Eco-Sense, located just outside of Victoria. This owner-built cob house is a multi-Petal-Certified Living Building. The Cascadia Green Building Council, with the help of grants from Vancity and the Real Estate Foundation, authored a comprehensive report on the project, available here: “Affordable, Sustainable Homes: Eco-Sense and the Future of Green Building” Also available is the Technical Report which served as the basis for the Cascadia report.  (Written by Gord Baird, Christina Goodvin of Goodvin Designs, and Ann Baird).

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Upgrading to a more efficient window. Does it pay off?

Apr 2, ’12 9:23 AM

Does it pay off to upgrade to a more efficient window? According to Steve Selkowitz, a leading thinker on energy efficiency and building science (who works out of the Lawrence Berkeley Lab), the answer is a definite yes– “If we add up all the energy and economic impact of windows in the US, it costs building owners about $40 billion a year. And I’d rather have the $40 billion in my pocket than sort of sending it out the window.” Put another way, the U.S. Department of Energy estimates that despite the push for more insulated walls and ceilings, 25 to 35 percent of the energy used in American buildings and homes is wasted due to inefficient windows and glass. The situation in Canada is not much better, and may actually be worse. In fact, we rank 27th out of 29 OECD (Organization for Economic Co-operation and Development) nations in terms of energy use per capita. This is more than five times the world average. Of course, we live in a colder climate than most, but isn’t that all the more reason we should be adopting better building codes that conserve the finite fossil fuels we are exporting in ever-increasing quantities? According to CMHC, every home in Canada requires the equivalent of 392 barrels of oil to build, and uses over 40 barrels to operate (a year). When it comes to making a more efficient window, technology has come a long way in recent years. Yet industry has been slow to adopt these improvements, primarily due to cost. Single and dual pane windows are still commonplace in many residential and commercial buildings today. Many people may be surprised to learn that dual and triple pane window technology was developed way back in 1865, around the time of the invention of the telephone and the presidency of Abraham Lincoln. Not until the 1930s did these more efficient windows gain industry acceptance. Triple-pane windows, coated with Low-E coatings (see below) are now commonplace in retrofits and new developments that want to achieve a lower energy and environmental footprint, but may have several disadvantages over more efficient window technology now available.There are a number of factors you should be aware of when it comes to choosing windows:

  1. U-Value (the measure of conduction or heat loss and gain through a material): The lower the U- value or higher the R- value of a window, the better. It’s important to look at the Full-Frame R-Value, not a centre-of-glass R-value. This is because the U-value of the unit is affected not only by the glass, but also by the frame the glass sits in. Many companies mislead consumers about the R-value of their windows; if and when they mention it, they may really be talking only about the centre-of-glass R-value, resulting in a much less efficient window than advertised.
  2. Coatings & Gas Fills: Low-E or Low-Emissivity coatings are invisible metallic layers deposited on a glass surface to impede heat flow through the glass. Gas fills may include Argon, Krypton or Xenon. These are injected into the airspace to improve the window’s thermal performance or R-value. Argon is the cheapest option and most common, but pricier gas fills will result in a more energy efficient window. It is also important that the seals used to hold in the gas fills are built to last. There is no point paying for expensive gas fills that leak out, leaving you with a standard, not particularly efficient window.
  3. Solar Heat Gain Coefficient: According to the Efficient Window Collaborative, “The SHGC is the fraction of incident solar radiation admitted through a window, both directly transmitted and absorbed and subsequently released inward. SHGC is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits.” Depending upon how your building uses sun angles for passive temperature control, you may want a higher or lower SHGC on different walls. Serious Windows offers options to fit your ideal design.
  4. Air Leakage Rate: This measures how much infiltration or leakage exists around a window or door. ALRs are typically shown in units of cubic feet per minute for square footage of area (m3 / s). The lower the number, the more airtight the window/door will be. Are more airtight window is a more energy efficient window, saving you money, long-term.
  5. Visible Light Transmittance: The VLT is the measure of how much light will make it through the glass. In most cases, the more layers of glass it has to travel through, the lower the amount of light that will shine through. Most windows have a VLT of between .40 and .70, whereas a single pane window would be almost 90%. Newer technology, called Spectrally Selective Glass (also called Solar Tuned), targets specific wavelengths of sunlight, to let in the short wave or visible spectrum and block the long wave or heat gaining spectrum, which may be highly desirable.
  6. Airspace Thickness & Suspended Film: On its own, glass has very poor insulative properties. This is why the boundary layer of air between the glass layers is also important. Widening the airspace can increase the R-value of the window. The use of Suspended films are helpful here to reduce the convection and energy transfer without the weight and size of more glass, achieving similar R-values as quadruple-pane windows.
  7. Materials Used/Durability: Some frame materials are superior to others. Metal frames tend to conduct a lot more heat than fibreglass or wood. Wood has long-term durability issues if not constantly maintained and may be chemically-treated. PVC plastic poses health issues, as its production creates dioxin and other potentially carcinogenic by-products. Many organizations are campaigning for its ban in building materials. Fiberglass frames are the best window frames available, being durable, strong, long-lasting, and aesthetically-pleasing. They can be painted multiple colours, and provide enhanced insulation. Weight should also be taken into account for windows. Some window technology such as quadruple-pane windows can have impressive U-values but are heavier and more cumbersome.
  8. Site Conditions: All of the variables mentioned are important, but none is perhaps more important than the actual site where your energy efficient windows are to be installed. Consideration must be taken when deciding what windows should go in what location. Conditions are different for every direction and even with respect to the layout of your yard. Depending on your situation you might want to have energy modeling done, or consult a qualified green building professional.

The world is changing quickly, and most global energy experts agree that energy costs are only going to increase and/or become more volatile in the coming years. Increasing the efficiency of your home is an excellent way to protect yourself from this volatility. Now is a great time to look at retrofitting your home—upgrading to a more efficient window and better insulation, etc. There are great incentives to take advantage of, such as the LiveSmart BC program, which may save you up to $110 per window unit. The City of Vancouver is offering a Home Energy Loan program (vancouver.ca/energyloan) that deserves consideration. Also check out Natural Resources Canada’s list of Grants and Incentives at http://oee.nrcan.gc.ca/corporate/1513. Unfortunately, at the time of this writing, the federal government program, EcoEnergy has been cancelled as of January 31st, 2012, by the federal Conservatives. Please visit saveecoenergy.ca and sign the petition to restore funding

Looking forward, other progressive initiatives coming down the pipe include: energy transparency when buying and selling a home—meaning you will know exactly how much energy a home uses and where it needs improvements or upgrades; green appraisals—where energy-efficient technologies are taken more heavily into account when determining the appraised value of a property, and nutrition-fact type labeling on building products, disclosing how a product was made, what chemicals were used, and whether or not the latter are carcinogenic.

Exciting changes are in the wind; don’t let them take you by surprise! If you are interested in learning more about our high-performance, energy efficient window line, Serious Windows, please give as a call at 604.379.9477

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HempWood Now Available!

Apr 2, ’12 9:19 AM

HempWood–Made from pure hempseed oil, this product penetrates deeply, is food safe and dries naturally with no harmful vapours. Cleans up with soap and water. It vividly accentuates wood grains. Use a brush, roller, sprayer or rag to apply. For interior applications, it’s best to build up coats until drying does not occur after 24 hours; then wipe off excess oil with a rag. For exterior surfaces, apply and re-apply as required to keep wood well coated for protection and appearance. Also works well with milk paint systems. Or blend HempWood 1:1 with pure turpentine to preserve wood underground (for example: fence posts).

Best for interior applications and performs well outdoors when you desire a “patina” look. Perfect for docks and decks too; it won’t harm the environment.

Comes in 250mL tin can, 4L plastic jug & 20L plastic pail with pour spout

Available by special order.

Come see us at the HiVE or call us at 604.379.9477 (info@biostruct.ca)

 

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