When it comes to green building, it seems everybody wants to jump on the band wagon these days. The Federal Government has its EnergyStar program, many states have programs, then there’s Passivhaus, and of course LEED. The problem is, the central focus of most of these programs isn’t so much green as it is energy efficiency with a dose of waste reduction on the side. And for desert there’s an offering of green sourcing—so long as it doesn’t conflict with goal number one, that great holy grail of green building: Net Zero!

Which begs the question: At what cost Net Zero? For that matter, is Net Zero even a laudable goal? It does, after all, come with quite a cost. Setting aside the cost of achieving Net Zero, just the mad rush to do blower door testing with all its calculations that ensure every little crack is sealed up tight has led to unintended consequences. Sick House Syndrome is headed in the direction of an epidemic. Therefore, if green building is defined as cost saving, it could be argued that obsessive air sealing isn’t such a great idea. What is saved in energy is more than offset by medical costs. To which the usual rebuttal is: If you’re going to air seal, you have to have properly installed mechanical ventilation. Okay.

To paraphrase a German architect I once met: You Americans are so in love with your technology. Why don’t you just open a window? Which might be interpreted as: When your solution to a problem creates another problem which must then be solved, thus creating another problem, you have no solution at all.

But the obsession with air sealing is only the tip of the ice berg. Net Zero inevitably leads to discussions about solar.

Solar. The new ‘green tech’ darling. Even President Obama got in on the act. The question is: Just how green is solar? Solar systems are constructed of aluminum, which must be mined, glass, the silica for which must be mined, plastic, which comes from oil, and worst of all, rare earth elements, which also must be mined. The environmental consequences of rare earth mining and refining are beginning to raise alarm bells that echo of oil production—or worse. As the New York Times reported earlier this year:

Once little known outside chemistry circles, rare earth metals have become increasingly vital to high-tech manufacturing. But as Malaysia learned the hard way a few decades ago, refining rare earth ore usually leaves thousands of tons of low-level radioactive waste behind.

So the world has largely left the dirty work to Chinese refineries—processing factories that are barely regulated and in some cases illegally operated, and have created vast toxic waste sites.

So our green tech darling, solar, is leaving a trail of radioactive waste behind it. This is green?

It’s beyond time the building industry got out of the kiddie pool and began to think more holistically about green building. We need to be thinking in terms of the environment around the building; we need to be thinking about where the materials we’re building with and finishing with are coming from; we need to be thinking in terms of the environmental cost of the entire production stream for those materials; we need to be thinking in terms of community. Not just the community in which the building will sit, but the communities around the world that manufacture the materials we put into the building—and who have to live with the often toxic refuse caused by that manufacturing.

When we do that, I guarantee Net Zero will become far less important than Environmental Zero, which may make Net Zero of zero importance.

I’d like to thank Toronto Stucco Contractor Skylar Bowker for the following guest post on the benefits of applying exterior insulation to existing masonry buildings and/or masonry substrates.

Recent studies have brought to light the advantage of exterior insulation versus traditional between-the-stud insulation. Among them: the ability for insulation to be continuous (instead of broken at studs), the superior longevity of rigid insulation versus fibreglass (which becomes less effective over time) and dew-point management. But how do you adhere rigid insulation to masonry substrates? Are you out of luck if you have brick? Isn’t drilling into masonry into time consuming and cost prohibitive compared to other cladding solutions? Not with adhesive.

Insulation can be installed on masonry substrates using adhesives because of the light weight of rigid insulations such as expanded polystyrene (EPS) or extruded polystyrene (XPS). The best solution for adhering insulation to a masonry substrate is actually a cement-based adhesive, such as one offered by an EIFS manufacturer (Dryvit, Sto, Senergy). These adhesives are Portland-cement based, but are modified with an acrylic component as well as fiberglass-mesh fibers that allow the cement to expand and contract with the insulation without cracking. This ensures that the rigid insulation maintains a strong bond to the masonry substrate for decades longer than traditional cement and doesn’t delaminate.

Additionally, because the insulation is being installed over a cementitious substrate a weather barrier isn’t typically required. While a cementitious-weather-barrier will never hurt, it does add to the cost and may be unnecessary. If the masonry substrate is crumbling or coming apart however, loose pieces should be removed and a skim coat should be applied to prevent further decay.

Anyone familiar with EIFS will know of the problems of incorrectly applying the cement adhesive to the back of the insulation boards. In order to prevent moisture from becoming trapped, the modified-cement adhesive must be installed in vertical “ribbons”. Using a 1/2”x1/2” notched trowel with 2” spacing between notches, apply the ribbons in a vertical fashion, which will allow water to drain vertically once installed on the wall. The insulation boards should be installed in sheets no larger than 24”x48”, laid lengthwise, and staggered. Sufficient pressure needs to be uniformly applied to the insulation boards so that the adhesive is pressed into the wall, but not so much as to flatten the ribbons and close up the drainage channels.

Is EPS or XPS better? The answer depends on your needs. If cost is a restriction, EPS is likely the better solution with its lower costs. If space is a constraint (as is common with closely-built downtown homes), the higher density of XPS will provide an equivalent R-value with less thickness, albeit at a higher cost. For example:

• EPS
  is R=3.75/inch (2.5” for R-9)
• XPS
  is R=5.6/inch (1.5” for R-8.4)

Nearly identical R-values, but the EPS is 1” thicker than the XPS. Note that EPS and XPS can have varying densities, which will affect the R-value per inch. While having “geometrically defined drainage cavities” (grooves cut into the back) is preferred for additional drainage, it’s not absolutely required. For more information on r-values, see http://en.wikipedia.org/wiki/R-value_(insulation)

There are a few systems/claddings available over the installed exterior rigid insulation boards. By far the most common is Exterior Insulation Finish Systems (EIFS, sometimes called “synthetic stucco”). To finish off an EIFS installation, alkali-resistant fiberglass mesh must be embedded into the EIFS base coat, and a finish coat applied at the very end. Various details such as control joints, proper termination at grade, flashing above wall penetrations and more need to be addressed, and as such a skilled EIFS applicator is usually recommended. A full detailed explanation is beyond the scope of this guide, but manufacturer guidelines can be found online or at distribution centers.

Heavier materials such as stone veneer, traditional stucco and brick veneer require a metal lath and possible extra reinforcing. This is beyond the scope of this guide, and the respective suppliers should be contacted for exact installation details.

Another alternative is foam-backed vinyl, which doesn’t have nearly as nice of a finish as EIFS but is more forgiving in terms of installation and can be installed/purchased at a lower cost. Vinyl siding manufacturers may or may not support the above specified installation process with a cementitious adhesive, and the manufacturer must be contacted for warranty information as well as their own installation methods.

There you have it. With the use of the proper cement adhesive, rigid insulation boards (EPS or XPS) can be installed directly over masonry substrates without the need to drill into walls. Not having a piece of metal sticking through the insulation also avoids thermal bridging, making your building as energy efficient as possible. Home owners, general contractors or architects in the Toronto area are invited to visit Toronto Stucco Contractor and contact Skylar Bowker to get a quote on having their new or existing building fitted with Exterior Insulation Finish systems.

EIFS, PES, XPS, insulation, exterior, masonry, cement

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I’d like to thank Philip J. Reed for giving us his opinion on what constitutes green building in the following guest post. Philip works in association with the Daybreak community in Utah. He has a close personal interest in green-friendly practices and sustainable living, and will be happy to follow up on any questions you may leave in the comments below.

Green building is a popular subject these days, but do you know what makes a building green? The concept relies on much more than environmental friendliness; economic development, transportation and infrastructure, land use, and still other ideas are all part all incorporated to promote a balanced, sustainable lifestyle.

At its core, this type of construction emphasizes the smart use of resources and processes to minimize the impact a structure has on the environment. Green buildings may contain products that have been reused, recycled, or made from a renewable resource. They support a healthy indoor environment and also employ smart landscaping, such as the use of native plants that won’t require extra water. Better designs minimize heating and cooling losses in a building, and make better use of energy as well. Even construction processes are more efficient, reducing the waste produced during building.

Spikes in energy prices and a significant environmental push in the 1960s and 1970s prompted early ventures into green building in the United States. The movement was formalized in the 1990s, and has continued to blossom today. To give builders a better sense of how to construct an environmentally friendly and economically smart structure, organizations such as the National Association of Home Builders have created Model Green Home Building Guidelines to provide more understanding of what constitutes green building and techniques to use which will facilitate the process.

Homes in Salt Lake are now constructed with a greener focus, and growing numbers adhere completely to EPA Energy Star® guidelines. Sustainable communities and neighborhoods now keep community gardens, walking and bike trails, activity centers, and community pools in mind. Business owners are incorporating smart principles into the design of their buildings, and several are LEED® certified. Even construction companies are doing their part by recycling a significant amount of their waste.

Those who believe in green building are passionate about the effects these practices can have on improving human and environmental health. Building choices, neighborhood design, and green infrastructure are all concepts which can have many beneficial results reaching far into the future.

References:

Daybreak Utah

U.S. EPA

U.S. Green Building Council

EPA Green Building FAQ

HGTV Pro (Article)