ICF's for Green Built, Energy Star, and LEED-H Many of us are glad to finally see corporations and homeowners with a desire to significantly reduce their impact on the world around them when they decide to build. At R-Value, we believe that both building owners and contractors should have the same goals when seeking to build green: Environmental responsibility. Of course one must seek to practice what one preaches. For both building owners and contractors this means not only looking at the financial bottom line when making decisions about which "green" products to use, but also looking at the environmental bottom line; it's effect on the environment, both locally and globally. That said, we have found that ICF's benefit both significantly. Several of the most significant methods for certifying environmental impact are NAHB's Green Home Building guidelines, EPA's Energy Star program, and the U.S. Green Building Council's LEED NC and LEED for Homes program. Each of these programs have guildelines to determine how much a home impacts the environment. Each has a slightly different emphasis. The NAHB program includes energy efficiency, local environmental impact, and occupant health. Energy Star is focused primarily on energy efficiency, and LEED-H has a greater emphasis on a home's larger environmental impact. Each program has it's positives and negatives; but I will commend the study of that topic to the reader. Our purpose today has to do with how the use of ICF's in your next project will assist you in achieving top honors in these certification programs. Feel free to skip to the section which pertains to the specific program you are interested in. NAHB Green Home Building. Some of you may already have a copy of the guidelines. I will be addressing only the items that ICF's directly affect, or contribute to. Section 1 Lot design, preparation, and development. 1.1.2 Choose and infill site. ICF's are constructed entirely from the inside, and require no off-road forklift; therefore can be constructed on very tight sites with minimal disturbance to the surrounding terrain. 1.3.4 &1.4.3 Minimize soil disturbance and erosion. Because we set ICF's from the inside of the home, we will not disturb the soil around the home. Section 2 Resource efficiency. 2.1.6 Use pre-cut or pre-assembled building systems or methods. ICF's are a modular system and all the pieces fit together like Legos®. Nearly all scrap is reused, and total waste is less than 1%. 2.1.7 Use a frost-protected shallow foundation (FPSF). This is not integral to ICF's, but is a service which R-Value is experienced in providing. Using a FPSF reduces foundation and excavating costs, as well as site disturbance (see 1.3.4 &1.4.3). 2.2.9 Provide a water-resistant barrier (WRB) or a drainage plane system behind the exterior veneer system or the exterior siding. An ICF wall is a WRB, and needs nothing further added to it beneath the exterior finishing materials. 2.2.11 Install enhanced foundation waterproofing. R-Value installs a 30 year warranty air-gap membrane waterproofing on all its foundations. Air-gap membrane waterproofing systems provide dual protection against water infiltration. 2.3.2 Reuse salvaged materials where possible. Depending on local availability, recycled aggregates can be used in the concrete used to fill the ICF. Fly-ash is another substance R-Value uses to replace up to 40% of the cement content in our ICF mixes. Fly-ash is a by-product of the coal industry that is diverted from the landfills. In addition, several ICF manufacturers use recycled plastics in their webs. 2.4.1 Use recycled-content building materials. See the above explanation. 2.7.1 Use products that contain fewer resources than traditional products. Certainly ICF foundations qualify for this, using 25% less concrete than standard foundations. When finishing a basement, no further wood needs to be used to furr the walls out. 2.8.1 Use locally available, indigenous materials. The aggregate in concrete is exclusively locally available and indigenous. 2.8.2 Use a life-cycle assessment (LCA) tool to compare the environmental burden of building materials and, based on the analysis, use the most environmentally preferable product for that building component. Due to their extremely high energy efficiency, as wel as the absorption of CO2 by the concrete throughout it's life. ICF's should perform very well on this test.
3.1.1 Home is equivalent to IECC 2003.... ICF's easily exceed this requirement both on a prescriptive basis and especially on a performance basis. Depending on the measure (and the form) used, ICF walls measure from an R-22 to R-32. ICF walls perform at over an R-50 level though! 3.1.2 Size space heating and cooling system/equipment ...with Manual J... R-Value uses a program developed by the PCA specifically for ICF homes in accordance with Manual J, which takes into account the thermal mass properties of an ICF wall, to determine the total loads placed on the structure. This information is furnished to the HVAC contractor for the design of the HVAC system. In addition to sizing the HVAC, this also estimates total energy usage for the year, and can be used to furnish the homeowner with an annual dollar amount he/she can expect to spend/save. 3.2.1 Home is X% above IECC 2003. Again, an ICF wall will perform significantly above IECC 2003 standards and should contribute to a home that is easily 40% over the standards. 3.3.1 Building envelope. ICF's are specifically listed here, and acheive the highest points possible under this section. Section 5 Indoor environmental quality. 5.2.2 D. Mechanical Ventilation, ERV. ICF homes are otherwise airtight, with about .01 air changes per hour versus .35 for a "tight" stick built structure. Due to this, an ERV is required to maintain healthy indoor air quality. An ERV exhausts stale air, while transferring heat to the incoming fresh air. Indoor air quality in an ICF home is much more contrilled than even a "tight" stick home, and ICF homes easily qualify for the Healthy Home designation from the American Lung Association. 5.2.5 Sub slab ventilation (future radon) R-Value uses Form-a-Drain to form the footings. This product integrates the footing forms, footing drainage, and sub-slab ventilation all in one very cost-effective step. Form-a-Drain costs at least 25% less installed than pouring footings, running drain tile, and running sub-grade tile for radon evacuation. All one needs to do to use the radon evacuation features is to finish running the PVC pipe out of the home. Using R-Value Concrete Structures to install ICF's for your next Green Built home can contribute 194 points toward certification, and should make Gold easily obtainable. "...Our position is that if you must build a large home, make the integrity of the building envelope your primary concern. You can include all the sustainable products in the world, but if the house has a low-quality building envelope it will consume inordinate amounts of energy to heat and cool over its lifetime, far outweighing any benefit acheived by using such products as low-VOC paint or woven rugs." The Editors, Green Builder magazine. Energy Star is unique in that it's sole focus is on energy efficiency and conservation, and does not look at other environmental factors like LEED-H and Green Built. Energy Star applies to any part of the home or any device in the home that consumes energy; such as the building envelope (our concern), gas and electric appliances, or lighting. As of July 1, 2006, Energy Star has received a pretty major overhaul in how they are rated. This makes it a bit more difficult for homes to meet the standard. Now an Energy Star home must be at least 15% better than the 2004 International Energy Conservation Code, which itself is better than Michigan's Energy code. On a scale where 0 means no energy used, and 100 is the IECC, an Energy Star home must be no more than 85 points. Michigan's current energy code receives about 116 points. Energy Star homes are inspected and tested by a certified energy rater to determine compliance and performance before they receive the rating. There are two ways to obtain an Energy Star rating: performance-based and prescriptive-based. The prescriptive method would look at the house and compare it to a given checklist; and as long as certain conditions were met and intems were included, the house would receive the rating. This is the method most production builders use, as they are not required to actually test the performance of every home they build. It is most likely that ICF´s will find their greatest use in custom homes, and so the method used to rate those will be the performance method. The total overall performance of the home will be tested, particularly how well it is sealed. Since ICF walls are by design airtight and extremely well insulated with continuous insulation, their specifications are considerably higher than IRC standards, and they perform well above that! A homeowner or builder looking to build an Energy Star rated home will find that the incorporation of ICF´s will easily meet and exceed Energy Star standards while giving occupants a quiet, safe, and comfortable home to live in. The LEED program has been a great sucess for commercial projects. The Insulating Concrete Form Association has written a technical brief describing how the use of ICF's contributes to LEED-NC points. I commend this to your reading; but please note that most of the items mentioned in this report are waully true and fitting for the other LEED certifications, such as those just coming out for schools, etc. I am working off of the Version 1.11 guidelines, I will only address the points that I belive are impacted by what R-Value can do. Innovation and Design Process 2.1 Durability Plan Water--Exterior Sources ICF walls are solid concrete, and the window bucks are usually built from vinyl. Both sides of the concrete are covered by at least 2 1/2" of EPS rigid foam insulation. There is nothing to rot or decompose. This makes an ICF wall more water resistant than any building sytem I am aware of. Below grade portions of the wall are treated to a heavy plastic dimpled membrane that esentially give it two lines of waterproofing protection. This product carries a 30 year dry basement warranty! Water--Interior Sources Again due to the weather resistant and non-decomposing nature of ICF walls, the interior side of the wall is not susceptible to water damage from washers and sinks, etc. Water Vapor Flow An ICF wall has no cavity for moisture to condense inside, and naturally has a very low permeability, making this a moot point as far as the walls go. Air Flow An ICF wall is solid reinforced concrete, and therefore is naturally airtight; even at the connection between the foundation and the main level; an area known to be troublesome in traditional construction. There are vastly fewer potential areas for air to leak (around penetrations only, not between plates and at seams) and thus it makes consideration of air leaks significantly easier. Heat Flow An ICF wall has continuous insulation, with no gaps or voids, no thin spots, and no thermal bridging whatsoever! You get the highest quality insulation and installation every time! R-Value also highly recommends and installs under-slab insulation below the basement slab to decrease downward and horizontal heat loss. The only area we don't address is the ceiling! Wildfire An ICF wall is concrete covered with EPS foam. The foam itself (on the fire side) must be well over 1000 degrees to sustain a burn. If it does, the concrete prevents the fire from spreading to the other side of the wall for 2 to 4 hours, depending on wall thickness and coverings. This is compared to 15 to 30 minutes for a traditional stick wall. And even if it does, the concrete wall will remain, and can often be reused when it comes time to rebuild the home. Pests Being a solid concrete wall, and the window buck usually vinyl, there isn't much for pests to destroy or consume. ICF walls have the advantage over wood structures. 3.1 Innovative/Regional Design The thermal mass of an ICF wall is an innovative way to reduce the heating and cooling loads on a building. During the summer, the concrete cools during the night, and absorbs heat energy during the day. The opposite happens during the winter, where the wall acts as a buffer between the indoor and outdoor temperatures, complementing the dual layers of insulation. 3.2 Innovative/Regional Design Use a Frost Protected Shallow Foundation as installed by R-Value to reduce the amount of excavation necesary, reduce the amount of materials used, and increase the energy efficiency of the building. Locations and Linkages 3.2 Select an Infill Site ICF walls are constructed almost entirely from the inside, thus very little room is needed on the outside of the structure; and infill sites do not pose a problem. ICF homes are a great choice for any tight location. Sustainable Sites 1.2 Minimize disturbed area of site As already mentioned, an ICF home is built mostly from the inside and can therefore contribute to minimizing site disturbance more than traditional framing methods. 4.2 Use Permeable Paving Materials R-Value can install permeable concrete for driveways and parking. This is an innovative choice that is proving to be durable even in our harsh climate. Permeable concrete also reduces the heat island effect you have with asphalt and permeable asphalt. Indoor Environmental Quality 1 Energy Star with IAP An ICF wall installed by R-Value has anywhere from 5" to 8" of continuous insulation, a very low rate of air infiltration, and no off-gassing. All of these things mean no extra attention needs to be given to the walls to meet this requirement. 3.1 Moisture Control--Analyze Moisture Loads AND Install Central System (if needed) An ICF wall keeps the moisture where it belongs. It will not pass through the wall, and neither will the air that carriers vapor. This makes moisture control less of a guessing game. 9.1 Radon Protection--Install Radon Resistant Construction... A Form-a-Drain footing system installed by R-Value not only does an excellent job of draining both the inside and outside of the footing to help keep the structure dry, it also integrates a radon evacuation system with no further work required. Simply vent it and it's done! Form-a-Drain is a footing form which stays in place to provide the footing form, drainage, and radon evacuation system in one cost-effective step. 10.2 Tightly Seal Shared Surfaces between Garage and Home. When the exterior walls of a home are constructed of ICF's you have as tightly sealed of a wall as you can get! No further work or special attention is required. Materials and Resources 1.2 Advanced Framing Techniques ICF's are an advanced framing technique, reducing waste to less than 1%. 2.2 Select Environmentally Friendly Products from List I am not aware of this list, so I can't be certain here; yet ICF's are the environmental choice in nearly every respect. I would expect ICF's to contribute points here. For more on this click here.
3.2 Reduce waste sent to landfill by 25% to 100% ICF's will contribute nothing to the waste stream if there is a good plastics recycling center nearby; otherwise there will be a very small amount of plastic to dispose of. Nothing like the dumpsters you see full of wood on stick homes! ICF's generate very little waste, even less than 1% is possible, depending on the brand of ICF chosen. In addition, R-Value recycles the foam which makes up most of the ICF, thereby eliminating even more waste. If Form-a-Drain is used to form the footings, then no waste is generated in scrap lumber, and Form-a-Drain generates no waste either. When V-Buck is used to form out the window openings, it also generates zero waste, and we can take any 2x waste from subfloor and interior framing and rip the pieces down to fit inside the V-Buck channels to provide a more robust attachment for the windows and to further reduce jobsite waste. Energy and Atmosphere 1.2 Exceeds Energy Star for Homes (1Pt./3 HERS index) An R-Value ICF home has from 5" to 8" of continuous insulation, ultra-low air infiltration, and high thermal mass. These items combine to make it the highest performing wall system I know of. If attention is paid to the areas that ICF's don't address, an ICF home will be able to obtain all possible points here with the least amount of work of any wall system. Total points ICF's and other products installed by R-Value contributed to: 62+ In Summary A couple of phrases being used in environmental circles are "embodied energy" and "carbon footprint". These terms are helpful to understand if one is truly interested in being a good steward of the environment. Embodied energy refers to the amount of energy it takes to manufacture a certain product, from mining the materials, to refining, assembly, and any other amount of energy used in it's production. This is a helpful factor in determining which of two seemingly equal products should be used. For example you could ask the manufacturer to demonstrate how his kind of carpet has less embodied energy than another (if someone claims they have a green product and can't answer this, walk away!). What embodied energy can't tell us is how much energy the product will consume or save over it's life, which can far exceed the energy it saved when manufacturing the product. This is beginning to happen via Energy Star, but their standards are rather loose, and only apply to a limited amount of items. Carbon footprint refers to the amount of carbon dioxide a product contributes to being released into the atmosphere throughout it's life. This takes into account both the manufacture of a product and it's energy usage throughout it's useable life. Since most energy production is by burning coal (which releases large amounts of CO2 in addition to mercury into the air), energy usage plays a large role. It can also refer to the amount of CO2 a piece of wood as a tree would have potentially absorbed. One can quickly see that products with longer life than standard are green simply because their embodied energy is factored out over so many more years. Conversely, an energy using product with a high carbon footprint will quickly undo any gain that low embodied energy gave, especially if it lasts a long time. An example would be a type of insulation that uses very little energy to make, but also doesn't perform nearly as well as others. Sustainability is another factor to consider in determining the environmental impact a product will have. For instance, when the lumber used on constructing a new home is unrated, it is not considered sustainable, since it removes trees from the environment; yet when the lumber is certified (by one of several organizations) then it is considered sustainable since for every tree harvested, one or more is planted. How sustainable is concrete? What about the foam? As of right now, the foam used in ICF's is not made from renewable products, though it could be. I don't know why manufacturers aren't beginning to use corn or soybean based insulations. Foam insulations are generally considered to be an excellent choice due to their superior insulating properties. Concrete is also a green building material, as it is made from inert ingredients, incorporates recycled content, and makes for a thermally efficient structure. The National Association of Home Builders has chosen concrete as their wall system of choice for the last several years in their New American Home; a cutting edge green home displayed at the International Builders Show. For a well-written article on using concrete in Green building, click here. Incorporating ICF's into your next project will not only greatly assist you in meeting the requirements of your program, but will significantly reduce your home's impact on the environment. To review, this is done in all of the following ways. 1) Significantly reducing energy consumption, 2) Greatly reducing jobsite waste, 3) Using recycled and locally available materials, 4) Providing a more readily controlled indoor environment, 5) The home will last significantly longer, thereby reducing life cycle impact 6) Eliminating the off-gassing of materials, 7) Carbonation of the concrete absorbs a large amount of carbon dioxide, a greenhouse gas, 8) Less area needed to construct, thereby reducing impact on local soils and vegetation ICF's are the answer to today's demands for a more environmentally responsible, lower operating cost building system. If you are interested in further information on any of these topics, you are encouraged to contact us or visit some of the industry websites, such as the Portland Cement Association, or the Insulating Concrete Form Association. "From an engineering standpoint--a far better wall than conventional stick-built!" Dr. Shirley Fleischmann; GVSU Padnos School of Engineering |
