In an era of conscientious green construction, architects, owners and contractors have been taking a closer look at both operational and embodied energy. A comparison of the embodied energy costs of various common building materials reveals some stunning variations. For example, the embodied energy of plastics like polyvinyl chloride (PVC) is more than 10 times that of cement and various concrete building products.
Just What Is Embodied Energy?
Embodied energy refers to all the upfront energy use of a given material, including:
- Mining, logging and other natural resource acquisition
- Electricity and fuel consumption during manufacturing
- Transportation expenses, including product delivery
It does not, however, factor in the operating costs of the building the materials are used in or the eventual disposal of the building materials used in creating the structure. Embodied energy, then, is only one component of the total life cycle energy costs of a building.
Life Cycle Assessment
ISO 14040:2006 is an international standard that addresses environmental management and sets appropriate life cycle assessment (LCA) protocols. A comprehensive life cycle assessment looks at the full environmental impact of either individual building materials or entire structures, factoring in:
- Raw materials acquisition
- Refining and fabrication
- Recycling and disposal
LCA looks at a wide range of environmental impacts like resource depletion, energy and water use, carbon emissions and waste generation
Failures Drive Embodied Energy Costs Higher
Performance has an impact on total life cycle costs; therefore, it is important to consider the losses and premature repairs that are associated with certain wall designs. Over the course of many projects, some of them will consume more embodied energy because of:
- Repairs due to wall system failures (mold, mildew, rotting and corrosion)
- Premature replacement due to natural disasters like hurricanes and tornadoes
- Fire losses
Embodied Energy vs. Operational Energy
Embodied energy is an increasingly important consideration because it is often equivalent to many years of operational energy. For example, one government agency calculates that the embodied energy in a typical home may equal as much as 15 years’ worth of operational energy. Even though it consists only of energy used to create and deliver the building materials, the embodied energy expended for a home that lasts a hundred years can account for as much as one-eighth of its overall energy use.
The Bautex™ Wall System only uses about half the concrete required in traditional ICF or concrete walls and it eliminates the need to apply an added layer of rigid foam sheathing. The embodied carbon in polyurethane rigid foam is 3.48 kgCO2/kg — more than four times the embodied carbon in cement (0.73).
Unsurprisingly, the embodied energy costs of a wall system that uses significantly fewer materials, like rigid foam sheathing, tend to be lower.
25 Percent Savings
Also, the more energy efficient the building is, the longer it will take for operating energy expenses to exceed the embodied energy costs. The Bautex Block Wall System reduces heating and cooling costs by 25 percent or more when compared to traditional wall systems. This is achieved by:
- Continuous insulation (and elimination of thermal bridging), which provides R-values that are 200 to 250 percent higher than those required in Texas by the 2015 IECC Energy Code.
- The efficient use of concrete in exterior wall systems, which increases thermal mass and optimizes external heat loads.
- Airtight building envelopes that are subject to fewer installation errors, reducing external heat loads.
The Bautex Wall System has low embodied energy when compared to many traditional wall systems. The four-hour fire rated blocks are fabricated using a patent-pending automated process at our plant in San Marcos, Texas. The peace of mind and other intangible benefits of the system merit consideration as well.
We’d welcome the opportunity to discuss what the Bautex Block can contribute to the success of your next project. For friendly, expert assistance, please contact us today!