Building Envelopes Take On New Meaning in Atlanta’s Changing Climate | Best Supply

In Atlanta’s hot, humid climate—where heat waves and rain squalls have become more severe—builders are adapting to a new environment where a tight, resilient building envelope isn’t just about energy efficiency anymore. It’s about protecting long-term performance and profitability.

With development still strong across Fulton, Cobb, Gwinnett and the outer suburbs, these issues affect almost every project type: retail tenant improvement, multifamily newbuilds, warehousing, institutional and everything in between.

For builders and contractors working in and around Atlanta, understanding these shifts isn’t just good practice, it’s becoming a competitive advantage.

Why envelope performance matters

Atlanta sits squarely in the Department of Energy’s Climate Zone 3A—identified as “Mixed-Humid”—where heat, humidity and significant rainfall all converge to stress wall assemblies.

It’s a region defined by long cooling seasons, short warm winters and extended periods of high moisture in the air.

Source: U.S. Dept. of Energy Building American Solution Center

Climate data from the National Oceanic and Atmospheric Administration confirms what contractors have already observed on the job: rising average temperatures, more days of 95 degree-plus heat and heavier rainfall events that challenge drying potential. When you combine hotter exterior surfaces, rapid humidity swings and frequent afternoon thunderstorms, you get an environment where moisture can accumulate quickly inside wall systems—and dry out very slowly.

That’s where envelope performance becomes essential. A well-designed and well-installed system controls the three fundamentals: heat, air and moisture.

Miss one, and problems like condensation, mold, degraded sheathing and higher energy costs become far more likely.

Recent code and standard updates

Georgia’s 2023 State Minimum Standard Energy Code—now in effect statewide—brings the biggest update in more than a decade. It’s based on the 2021 International Energy Conservation Code (IECC) and ASHRAE’s updated Energy Standard For Sites and Buildings Except Low-Rise Residential Buildings.

Here are three changes in the statewide code that builders should care most about:

1. Continuous insulation matters more: The new standard tightens expectations for continuity—especially at transitions—requiring better alignment among air barriers, insulation and cladding attachments. This affects multifamily, offices, schools and light commercial shells.
2. Air barriers are no longer optional: Projects must include a continuous air barrier and demonstrate compliance through either testing or detailed inspection pathways. For builders used to relying on “airtight drywall” or “good craftsmanship,” this represents a meaningful shift in verification.
3. Inspections are more rigorous: Field inspections now place greater emphasis on envelope transitions, penetrations and sequencing. Contractors who document work with photos or videos—especially on complex assemblies—tend to pass with fewer callbacks and delays.

Product & material trends in the southeast

Fluid-applied barriers: The Air Barrier Association of America (ABAA) recommends the use of fluid-applied systems because they create a seamless, fully adhered air and water barrier—ideal for complicated geometries and renovations.

These systems reduce the risk of fastener penetrations and depend less on perfect tape adhesion in hot, humid weather.

Hybrid insulation assemblies: High-performance wall designs that combine exterior rigid foam or mineral wool with interior batt or spray foam are becoming more common in multifamily and school construction, according to the Grip-Rite blog. These “continuous insulation” wall systems offer better dew-point control and lower long-term energy use.

Cool roof technologies: As heat waves become more frequent, cool-roof membranes and coatings are gaining traction on Atlanta's commercial roofs. According to the U.S. Department of Energy (DOE), they reflect more solar energy, reduce cooling loads and extend membrane life.

Low-VOC sealants: The DOE also notes that “reducing the amount of air that leaks in and out of your home is a cost-effective way to cut heating and cooling costs, improve durability, increase comfort, and create a healthier indoor environment.” Low-VOC sealants that meet LEED v4.1 criteria are an environmentally sound way to close gaps, reduce air infiltration and improve indoor air quality—without the odor and curing issues of older chemistries. They’re now standard on many public and private projects.