Concrete, Sustainability and Code Updates

DSCN0557

Recent code updates address building safety, durability and sustainability. Architects often design with concrete to deliver code compliance. The longer life cycles and reduced maintenance of concrete structures enhance sustainability. They reduce the frequency of repairs and replacements, enhancing sustainability.

The International Building Code (IBC) is a model code. Each jurisdiction sets and enforces its own codes. IBC updates occur every three years. The most recent version is ICC IBC-2018.

Code Updates and Sustainability

Updated codes impact concrete construction in a variety of categories. Codes about energy performance and solar reflectance focus on sustainability. A SpecifyConcrete.org graphic discusses the implications of certain building code updates.

Energy performance

Insulated concrete forms (ICFs) meet more stringent energy standards. They combine the benefits of continuous insulation and thermal mass. ICF projects often achieve energy savings of 40 percent or more.

Projects should exceed International Energy Conservation Code (IECC) standards by 20 percent. ICF construction meets such standards with ease.

Solar reflectance

Code updates also focus on cool roofs that better reflect the sun’s light and radiation. The 2018 code update specifies that solar reflectance meet one of two standards:

  • No less than a 3-yr aged solar reflectance of 0.55 plus a 3-yr aged thermal emittance of 0.75
  • 3-yr aged solar reflectance index of 64

Albedo is a measure of solar reflectance noted on a scale of zero to one. A zero albedo denotes 100 percent solar energy absorption. An albedo of one denotes 100 percent solar reflectance.

Excess heat gain drives cooling costs higher. Heat islands in urban areas are a real concern. As a result, you’ll often find solar reflectance indices in newer building codes. Inherently light-colored concrete is well-suited to reduce heat gain. TiO2 concrete delivers some of the highest solar reflectance in the business.

Mitigating Hazard Risk

Extreme weather events drive demands for more resilient construction. The Portland Cement Association (PCA) calls for codes that better promote resilient construction.

MIT’s Concrete Sustainability Hub (CSHub) calls for more stringent codes that account for urban wind conditions. A CSHub Fact Sheet released in May of 2020 says, “The layout, or city texture, of a community can dramatically magnify wind loads. Current building codes, though, don’t consider this contextual effect, leaving many communities at risk.”

Resilient construction can be cost-effective as well. One MIT study looked at a hypothetical $10 million project. Researchers calculated that $340,000 invested in hazard mitigation is recouped in full over the building’s life cycle.

Wind resistance

Concrete is ideally suited to meet mandates for a 20 percent increase in wind pressure and design force. There also updates requiring a five percent increase for critical infrastructure building projects. These were already the subject of more stringent standards in the past.

When reinforced on both horizontal and vertical planes, ICF walls can withstand winds of 180-220 mph. The NRMCA profiles an ICF home in Mississippi that survived Katrina. The residence featured concrete walls, floors and roof.

Flood resistance

Flood resistance is also the subject of updated codes. Designs are to use one of two standards:

  • The 500-year flood elevation
  • Three feet above base flood elevation

Designers cannot rely on protective measures like dams and levees to meet standards.

Fire safety

Fire safety experts often approve of building codes requiring non-combustible materials. Debate continues over the merits of cross-laminated timber (CLT) construction vs. concrete construction. Wood-framed buildings contain more combustible materials. They are often more prone to collapse in fires. The safety of both occupants and firefighters is at stake. There is another benefit that multiplies year after year. The safer the structure, the lower the cost of insurance coverage.

High-performance fire safety includes structural fire resistance requirements for all buildings. Redundant fire safety features apply to residential and assisted living communities. These features recognize the needs of an aging population. Code updates expand mandatory sprinkler requirements as well.

Storm shelters

Residential and commercial storm shelters provide protection in tornadoes, hurricanes and more. Commercial shelters must provide a safe haven for dozens or hundreds of individuals.

Concrete is the go-to material for meeting ICC 500 standards for the design and construction of storm shelters. A FEMA report highlights key provisions. According to a map in the report (Figure 1), storm shelter design wind standards range from 160 mph in eastern PA to 260 mph in the western part of the state.

Additional Updates

There are now more stringent Sound Transmission Class (STC) requirements for residential buildings. These standards are broadly defined to include single-family homes, apartments, hotels and motels. STC ratings attest to how well a structure attenuates sounds ranging from 125 to 4000 Hz. An STC rating is the decibel reduction delivered by a given building material.

IBC 1207 sets a minimum STC 50 in multi-family walls and ceilings. ICFs deliver code-compliant sound attenuation in exterior and interior walls, floors and ceilings. Check out our infographic on ICF sound attenuation. Wood buildings often have STC ratings in the 30s, while ICF structures attain STC ratings in the 50s.

Other IBC code updates address materials transportation, recycling and pollution prevention. There are also updates to site development and site improvement requirements. Some provisions don’t directly involve primary building materials. Enhanced CO2 detection is one example. Many new standards do address sustainability, however. For example, reductions in building water use. Updated air filtration system requirements will improve air quality.

The Portland Cement Association discusses code updates pertinent to the industry here.

Learn More

The Pennsylvania Aggregates and Concrete Association (PACA) serves industry professionals committed to code-compliant designs and design execution. If you need more information, please contact us.

Recommended Articles

12513927 10154127998102958 4719328728095904235 o

February 22, 2024

Understanding Whole Life Carbon in the Concrete Industry

Proficient carbon calculations are increasingly important as “Buy Clean” legislation proliferates. New York and Colorado are among the states that now require carbon calcs for public projects. An estimated 40% of emissions are from the built environment. According to one estimate, the planet’s total building floor area will double by 2060. This makes the concrete industry a key player in the quest for net-zero emissions products and projects.

Concrete Curing full

February 15, 2024

California: Coal-fired Cement Plants to Net Zero by 2045

The Natural Resources Defense Council (NRDC) notes that cement production is “so carbon intensive that even though cement makes up less than 15% of concrete by weight, it accounts for 90% of concrete’s carbon footprint.” The use of fossil fuels to fire cement kilns is a key source of these carbon emissions.

Featured image

February 08, 2024

Toward Net Zero Concrete: Global Initiatives

In the quest for reduced greenhouse gas (GHG) emissions, everyone has a role to play. In the concrete industry, this includes everyone from manufacturers to contractors, and from trade associations to governments. Here is a review of some of the major initiatives impacting concrete’s sustainability.

Concrete construction building

February 01, 2024

Graphene-Infused Metakaolin for Stronger Concrete

Ordinary Portland cement (OPC) requires high-temperature calcination of limestone. It is possible to use various emissions-reducing pozzolans in concrete. Fly ash comes from coal-fired power plants. Ground granulated blast furnace slag (GGBFS) comes from steel mills. Another SCM is metakaolin derived from kaolin.

Adobe Stock 465164163

PACA's Online e-Learning Center

The program is delivered in one (1) module and it should take approximately 30 minutes to complete.  You will receive a certificate of completion once you pass the quiz. The bookmarking feature will allow you to leave the course and resume where you left off when you return.

The Pennsylvania Aggregates and Concrete Association (PACA) is the industry’s unified voice, representing more than 200 member companies across the state.