Green Building in Georgia - Trends
The list of topics covered under our ‘Green Building Section’ for Green Harbor Building Solutions based in Athens Georgia are as follows:
- Green Building – an Overview
- What is LEED?
- Why choose LEED?
- LEED with Fox-Blocks ICFs
- Profile of Fox-Blocks ICF Buildings with LEED Certifications
- Net-Zero Energy Buildings
- Net-Zero Energy (NZE) Homes with Fox-Blocks ICFs
- Passive Solar Buildings, Passivehaus or Passive House
Green, or sustainable building is the practice of designing and building structures and implementing processes that are resource efficient and environmentally responsible for the duration of a building’s life-cycle: from the selection of the building site to design, construction, operation, maintenance, renovation, and demolition; or, in more concise terms, green building design entails striking a balance between building construction – residential and commercial –and the sustainable environment. Green building projects require the close collaboration of all stakeholders in the project to include the building owner(s), design team, architect, engineer(s), contractor(s), & building inspectors during all project phases.
Though green building technologies are rapidly evolving in efforts to improve and complement current green design and construction methods, the overriding purpose of sustainable building will always be to minimize the total impact of newly constructed or renovated buildings on human health and the natural environment. This purpose is accomplished by:
- Efficiently using and conserving energy, water, and other resources
- Protecting occupant health and improving employee productivity
- Reducing waste, pollution, and environmental degradation.
- For more information concerning green building, contact the US Green Building Council at www.usgbc.org.
Leadership in Energy and Environmental Design (LEED) provides independent verification of a building or neighborhood’s green features, allowing for the design, construction, operations and maintenance of resource-efficient, high-performing, healthy, cost-effective buildings” as stated by the US Green Building Council (USGBC), the organization that developed the LEED green building certification program. According to the USGBC “LEED certified buildings save money and resources and have a positive impact on the health of occupants, while promoting renewable, clean energy”. The USGBC further defines LEED as “a green building certification program that recognizes best-in-class building strategies and practices” and further states: “Leaders across the globe have made LEED the most widely used green building rating system in the world with 1.7 million square feet of construction space certifying every day. More than 60,000 projects are participating in LEED across 150+ countries and territories, comprising over 11 billion square feet.
LEED version 4 (v4), released in November 2013, is the latest version of the LEED Certification program which clearly states what the USGBC wants its LEED projects to accomplish. These goals (7) are referred to as “impact categories” that are listed as follows:
- Reverse Contribution to Global Climate Change
- Enhance Individual Human Health and Well-Being
- Protect and Restore Water Resources
- Protect, Enhance, and Restore Biodiversity and Ecosystem Services
- Promote Sustainable and Regenerative Material Resources Cycles
- Build a Greener Economy
- Enhance Social Equity, Environmental Justice, and Community Quality of Life
To acquire LEED certification, green building projects must satisfy prerequisites and earn points to achieve the target certification level for the selected rating system. “Prerequisites and credits differ for each rating system, and teams choose the best fit for their project” as stated by the USGBC. There are five rating systems that address multiple project types:
- Building Design and Construction (BD+C)
- Interior Design and Construction (ID+C)
- Building Operations and Maintenance (O+M)
- Neighborhood Development (ND)
- Green Homes
The USGBC further explains how building projects qualify for LEED certifications: “Each of the five rating systems is made up of a combination of credit categories. Within each of the credit categories, there are specific prerequisites projects must satisfy and a variety of credits projects can pursue to earn points. The number of points the project earns determines its level of LEED certification.”(Go to www.usgbc.org/leed for more information regarding specific credit categories.)
There are four levels of certification which are listed as follows along with the points ranges required to achieve each of these levels:
- LEED Certified: 40-49 Points
- LEED Silver: 50-59 Points
- LEED Gold: 60-79 Points
- LEED Platinum: 80+ Points
The USGBC states: “LEED certification means healthier, more productive places, reduced stress on the environment by encouraging energy and resource-efficient buildings, and savings from increased building value, higher lease rates and decreased utility costs. In fact, 88 of the Fortune 100 companies are already using LEED.” Given the facts that US buildings account for 38% of all CO2 emissions, 13.6 % of all potable water (15 trillion gal/year), and 73% of electricity consumption, and that LEED projects are responsible for diverting over 80 million tons of waste from landfills (figures provided by the USGBC), it is easy to understand why the LEED certification is so highly sought after when seeking to build Green in Georgia.
Paramount to the attainment of a LEED certification for green building is the manner in which the building’s structural shell or envelope is constructed. In fact, ICF structures have the potential to contribute 32 to 34 points toward the attainment of any one of the four LEED Certifications (Certified, Silver, Gold, or Platinum) within the rating system of LEED Building Design and Construction (BD+C) – the rating system that addresses the design & construction of the building’s structural shell. These potential point totals constitute from 40 to 43% of the point threshold for the LEED Platinum certification to 80 to 85% of the point value required to attain the LEED Certified certification. (See the USGBC link at www.usgbc.org for more in-depth information on the rating categories and the building types within the BD+C rating system.) Of the eight rating categories within the BD+C rating system- four of these categories – Energy and Atmosphere, Material and Resources, Indoor Environmental Quality and Sustainable Sites – can potentially contribute to acquiring LEED points.
Given the relatively high weighting that the exterior shell of the building contributes to the overall point totals needed for achieving a LEED certification, it becomes clear that any planned green building project that will be seeking this distinguished building award must begin with a durable, resilient structure that:
- is highly energy-efficient
- involves materials and processes that are sustainable and which create little to no unusable waste and relatively small quantities of gas emissions that are harmful to the environment
- enhances the interior environmental quality
- minimize disturbances to the environment in and around the building site
The remarkable energy efficiency characteristics of ICF walls result from a combination of significantly higher R-values (lower thermal conductivity) and extremely low air infiltration (thermal convection) for EPS insulation, and the inherently large thermal mass of concrete when compared to stick built homes with fiberglass insulation (please see Benefits of Building with ICFs for a more in-depth comparison between ICF and wood frame homes). Energy losses can be reduced 30-45% simply by using ICFs for walls instead of 2X6 or 2X4 wood framing. The sustainability of EPS insulation and the processes used to manufacture and build with this product make ICF construction a very green building choice. EPS is 100% recyclable and the only volatile organic compound (VOC) emitted during manufacturing is pentane, a non-CFC chemical that is in the 0 to 0.2% range; the majority of the pentane is broken down into water and CO2 by a photochemical reaction. Research at the University of Victoria in Canada shows that the methane released during the decomposition of paper cups is 50 times higher than the pentane that is emitted during the manufacture of EPS cups. In addition, EPS insulation waste resulting from ICF construction is in the 1 to 2% range for Fox-Blocks ICFs, and EPS waste constitutes only 0.1% of Municipal Solid Waste.
The unique features of a Fox-Blocks ICF wall combine to yield a high-quality interior living environment that is almost unattainable by any other building method. The air-tightness of ICF structures greatly reduces unwanted heat losses and gains that occur through thermal convection which is typically the largest contributor to heat loss (40%) in wood frame homes. The low air infiltration property of ICF structures ensures that the building occupants never experience drafts in the interior of the building; in addition, it acts to filter-out allergens, dust and other harmful agents that affect occupant health. What’s more, EPS insulation does not absorb moisture and its mechanical and thermal properties are unaffected by damp, humid environments. Finally, the thermal mass property of concrete enables it to store vast quantities of heat from the exterior in the daytime (when the outside temperature is greater than the inside) and then slowly release the stored heat to the interior of the building at night (when the outside temperature falls below the inside temperature) – keeping the inside comfortable using almost zero energy.
The fourth credit category in which ICF construction can make a lasting effect on the environment and also score points toward the achievement of a LEED certification is the Sustainable Sites category. Within this category, the Heat Island Reduction sub-category is an area where ICF construction can contribute to the attainment of a LEED award. Through the use of highly reflective, eco-friendly exterior wall materials that can easily be installed on ICF wall surfaces, the Heat Island Effect experienced with new construction can be mitigated by reflecting a high percentage of the solar radiant heat that would otherwise be absorbed by the walls causing a rise in temperature of the structure. Another way that construction materials can be used to greatly decrease the Heat Island Effect is through the selection of roofing materials that have a relatively high solar reflectivity – a scale (0 to 1.0) that measures the percentage of incident solar radiant heat that is reflected away from the surface of the material. Concrete is an excellent reflector of solar energy by virtue of the relatively high solar reflectivity of the sand, cement, and other cementitious materials in the concrete. Concrete made from white Portland cement has a solar reflectivity of approximately 0.7 which means that only 30% of the incident solar radiation is being absorbed by the concrete roof. Thus, concrete roofs such as those that are constructed using ICF concrete deck forms, will cause large reductions in the Heat Island Effect for new construction.
As a concluding note on the capabilities of ICF structures to minimize the impact created by new construction, it is important to recognize that the lifecycle of ICF buildings is measured in centuries compared to decades for stick-built homes. Given the long life and relatively low maintenance requirements for ICF buildings, the frequency and extent of building renovations and repair operations that can cause disturbances to the surrounding environment are greatly diminished.
When Dr. Jim Farr, the Executive Director of St. Croix Valley Habitat for Humanity (SCVHFH) in River Falls, WI and the Board of Directors decided to embark on the development of an innovative, sustainable community and wanted to secure a LEED for Homes Platinum certification, he knew he needed construction products that would enable him to achieve his goals. Fox Blocks Insulated Concrete Forms (ICF) was one of the construction product partners that proved to have both the experience and commitment to sustainability needed to be a valuable asset to the Habitat for Humanity home construction in the Eco Village.
Continue reading the rest of the article on this LEED Certified ICF development from Fox Blocks...
Simply stated, a Net-Zero Energy building produces sufficient energy using on-site renewable energy sources (solar, earth, or wind) to supply all of the heating, cooling and other energy needs of the building occupants. The Net-Zero Energy rating is calculated by comparing the total amount of energy that the building produces on-site to the total energy consumed on an annual basis. The term “Net” is used to acknowledge the fact that at any given interval of time during the year, the amount of energy being produced may not equal the amount being used, but by the end of the one-year period the building will have used no more energy than it actually produced. For example, Net-Zero Energy buildings typically remain connected to the power grid so that during times when the on-site renewable energy sources produce more energy than is being used by the building, this excess energy can be sent to the grid. Conversely, during times of peak energy demand when on-site energy sources cannot keep up with the energy consumption rate, the building will receive sufficient power from the grid to meet the increased demand. In effect, the amount of energy sent to and received from the power grid will be equal on an annual basis. Some buildings attain a point of Net-Positive Energy when the amount of energy produced exceeds the energy needs of the structure within a year, thus providing a revenue stream for the building owners derived from selling the excess power to the grid.
Currently, renewable energy sources such as photovoltaic solar panels are relatively expensive which provides building owners the incentive to accurately size these systems to just meet forecasted energy demand on an annual basis. In order to hold-down the cost for these clean energy sources, it is important to reduce the energy appetite of the building through any available means such as ensuring that the building incorporates as many passive solar building features as are available/practical and by using green HVAC systems - geothermal, solar-thermal, radiant hydronic, & Energy Recovery Ventilators (ERV) - that have demonstrated the capability of yielding enormous energy savings while maintaining clean, healthy living environments for building owners/occupants.
Net-Zero Energy (NZE) Buildings with Fox Blocks ICFs:
Today, building owners in pursuit of green building credentials such as NZE, LEED, and passive solar in Georgia and the east coast of the USA realize that the starting point for the achievement of this objective is a durable, resilient, and a highly energy-conserving structural building envelope. As green building requirements become increasingly more stringent, many building professionals – architects, contractors, engineers, developers, etc. – have abandoned traditional building methods such as wood frame and concrete block in favor of ICFs. These professionals are quickly learning that the ICF building system is the “one-stop” solution that doesn’t require costly additional materials and processes (as is required with legacy building systems) to achieve the rapidly evolving green building standards by design.
Please note that three of the four elements – High R-Value Insulation, Concrete Thermal Mass, and Airtight Construction – associated with the Insulate and Seal the Building Envelope component of building a NZE home are provided by the ICF building system. Starting with a building envelope that provides the super-insulating characteristics of EPS foam, the extremely low air infiltration permitted by ICF walls, and the heat storage capacity from the thermal mass of solid concrete walls (plus floors & roofs) minimizes the heating and cooling loads that must be accommodated by onsite renewable energy sources in an NZE building.
Net Zero Energy subdivisions planned with ICF construction for maximum energy efficiency.
Two net-zero energy developments, built with homes that generate as much energy as they use, are being built with insulated concrete forms to ensure energy efficiency and comfort. Anthony Aebi, the founder and CEO of Greenhill Contracting, Inc has a single goal for his contracting company: to build the next generation of homes that achieve the highest level of energy performance, so high that the annual outcome is net zero energy usage. Most importantly, he wanted to build the home at a cost-per-square-foot under $100. Aebi is achieving his goal with his two developments: Green Acres, the first Net Zero Energy community under development in Hudson Valley, New York, and The Preserve at Mountain Vista in New Paltz, New York.
Continue reading more on this Net-Zero Green Building ICF project with Fox Blocks...
Passive Solar Design
In a single statement, passive design responds to local climate and site conditions ( Insolation ) to yield maximum comfort and health for building occupants while minimizing energy use. Passive solar design is the best place to start for achieving the highest levels of energy efficiency and environmental air quality with minimum to no reliance on mechanical heating and cooling. In fact, According to CanPHI, the Canadian Passive House Institute, passive solar buildings (new construction) can achieve energy performance savings of 80 to 90% when compared to conventional construction methods such as stick frame.
Passive House Institute US (PHIUS) lists 5 principles of passive design that are as follows:
- The use of continuous insulation throughout the entire building envelope without thermal bridging
- The building’s structural envelope is extremely airtight, preventing infiltration of outside air and loss of conditioned air.
- It employs high-performance windows (typically tripled-paned) and doors
- Solar gain is managed to exploit the sun’s energy for heating purposes and to minimize it in cooling seasons – the effective use of Insolation in Passive Solar Design
- The use of balanced heat-and-moisture-recovery ventilation and a minimal to no dependence upon space conditioning systems.
Though the above design principles vary to some degree throughout the world in the emphasis placed upon individual principles, the Passive Building institutes and governmental agencies from the different parts of the globe show consensus in the need for the following passive design components that address building construction methods specifically:
- High-Performance Insulation: Passive design must include insulating materials that will reduce heat loss or gain throughout the entire building shell for the life of the building. The level of insulation depends upon the climate zone where the building will be constructed.
- Thermal Mass: Critical to the achievement of passive solar design is the use of materials that provide thermal mass in the interior of the building. Thermal mass is the capacity of a material to store heat energy. For passive heating, the thermal mass – high-density materials such as concrete, brick, or stone – is exposed to direct sunlight and acts to store the radiant heat of the sun’s rays. Thermal mass in the interior of a building can be in the form of a concrete floor and/or wall.