Since November 2016, builders and architects in Texas must comply with the 2015 International Energy Conservation Code (IECC) for both commercial and residential construction. Texas adopted the 2015 IECC to lessen energy use and costs to businesses and homeowners. In fact, the ICC reports an increase in energy efficiency by 18 percent in residential and 26 percent in commercial structures after implementation of the IECC 2015 standards over the previous IECC 2009 standards.
By requiring the 2015 IECC latest energy codes, Texas is leading the way toward reducing CO2 emissions and advancing the goal of the World Green Building Councils (GBCs) to achieve net zero carbon by 2030 for all new construction. Builders and architects in Texas must meet the challenge to build and design all projects according to the 2015 IECC codes.
Compliance with the codes ensures achievement of the highest standards of energy efficiency, safety, and durability for today’s building projects in Texas.
Building Projects Must Comply with Both State and Local Energy Codes
All commercial and residential projects greater than three stories must meet energy efficiency requirements according to the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE 90.1) or the 2015 IECC codes and standards.
The design of the structures must also consider the total building performance, including air leakage, mechanical systems, water heaters, lighting, and metering.
Builders and architects must not only comply with the 2015 IECC codes, but also those of their local jurisdictions. In Texas, local jurisdictions can amend and adopt local energy code, so long as the modified code is not less stringent than the code adopted by the state.
To avoid confusion between local and state codes, builders and architects should begin designing all projects to the 2015 IECC standards, then implement additional local requirements.
Building Envelope Options for Exterior Walls
For the building envelope of a commercial building, there are three energy code compliance options typically used by architects.
- Insulation component method: Building a structure that meets the 2015 IECC and ASHRAE 90.1 standards for energy efficiency requires achieving specified R‑values for continuous insulation around a building’s envelope. The ASHRAE Standard 90.1−2013 defines continuous insulation as insulation that is uncompressed and continuous across all structural members without thermal bridges other than fasteners and service openings. Section C402.1.3 of the 2015 IECC specifies the amount of insulation required for different opaque wall types (mass walls, metal buildings, metal framed, and wood framed).
- Thermal conductivity component method: Section C402.1.4 general prescriptive of the IECC 2015 specifies the maximum cumulative U‑Factor (or thermal conductivity) of all the components in a wall assembly for different opaque wall types (mass walls, metal buildings, metal framed, and wood framed and other). The code also provides a table for calculating the U‑Factor of cold-formed steel stud wall systems with different levels of cavity insulation.
- Component Performance Alternative method: Section C402.1.5 of the general prescriptive of the IECC 2015 specifies that the weighted average of U‑Factors of the envelope assemblies, based on surface area, is less than the weighted average maximum U‑Factor permitted in IECC Table C402.1.4. The component performance alternative method allows designs to increase performance in one area of building to compensate for degraded performance in other areas. Verification of compliance for this option is typically done using COMcheck software.
Continuous Insulation Options for Exterior Walls
The IECC includes a climate zone map which divides the country into eight zones: zone one is warmest and zone eight is the coldest. The three major climate zones in Texas are two, three, and four. Each zone is assigned a building envelope insulation requirements for different wall systems using the insulation component R‑value method.
The different wall systems include wood-framing, metal framings, metal building, and mass walls (concrete and masonry). Mass walls are exceptionally energy-efficient because they can absorb and release energy over time.
Therefore, the required R‑value for mass walls is lower (less insulation requirement) than required R‑value for light framed or steel wall assemblies.
Bautex Wall System Helps Builders Meet the Latest Texas Energy Efficiency Codes
The easy to install Bautex Wall System, manufactured in Central Texas, helps contractors and architects meet the challenge of building according to the latest Texas energy efficiency codes without overspending on materials or labor.
The Bautex Wall system exceeds the 2015 IECC requirements for continuous insulation, thermal mass, and an air barrier for all climate zones in Texas. The Bautex Wall System is also a four-hour load-bearing fire-rated wall that provides excellent fire protection. Please visit Bautex Wall System learn more on meeting the latest Texas energy efficiency codes.