Page 23 - Builder Brief January 2023

INSPECTIONS | ENERGY TESTING | ENGINEERING
832-524-5212 www.burgess-inc.com
As we begin the New year, it’s time to begin preparing for new construction requirements for 2023. Today, we are focusing on the city of San Antonio’s adoption of the 2021 IECC, which goes into effect for all starts as of February 1st, 2023.
Residential new construction builders will have several paths to comply with this code:
• Simulated Performance Path
• Prescriptive Path
• Energy Rating Index
• House Bill 3215 HERS Index • Energy Star for Homes v3.1
The 2021 IECC is based on 6 chapters. Below is a summary of the most significant changes from Chapter 4 of the IECC, which covers Residential Construction Energy Efficiency.
Let’s now jump into the compliance path options:
Performance Path - uses the proposed design and the standard reference home to compare annual energy costs. Compliance is based on the
proposed home having an annual energy cost that is equal to or less than the reference home. Working with a HERS rater or an IECC plans examiner is critical for this path; they will run these calculations in approved software and can assist in the evaluation of your current specifications.
Prescriptive Path- R401-R404 - requires homes to comply with all mandatory measures along with the prescriptive R-values listed in R402.1.3. This is the least common path for most builders in Texas, as it lacks flexibility for trade-offs.
Energy Rating Index- R406 - utilizes the ERI calculation to determine compliance with the code. The minimum ERI target for Climate Zone 2 is 52, along with several mandatory requirements that make this a realistically unachievable approach to compliance. Example: R406.3 requires the building thermal envelope to be 15% more efficient when there are no on-site renewables. This means if your house is equal to the prescriptive table, you would need to make a 15% improvement in the insulation and window values just to meet this prerequisite.
House Bill 3215 - allows the HERS index to be used to show compliance with the 2021 IECC. The homes under this path must meet the mandatory requirements of the 2018 IECC AND have an envelope that complies with R402.1.2 or R402.1.4 of the 2018 IECC. So what does this mean? If you build a home to the 2018 R-value table, you are gaining flexibility with other components (i.e. mechanical systems, appliances, lighting) to achieve the HERS index threshold adopted by the state of Texas.
Energy Star - similar to HB3215, Energy Star certification is codified into state law and is a viable path to compliance with the IECC. It also uses the HERS index, and some additional programmatic requirements, to provide a valuable option for high-performance homes to comply with code. It does require some pre-planning with your HERS rater to evaluate current building specifications, mechanical system design, and other standards of practice; but in doing so, you may be able to utilize the certification for both IECC compliance and qualification for the 45L tax credit.
What else do you need to consider from the 2021 IECC?
Section R401.2 establishes additional mandatory requirements applicable to ALL IECC compliance approaches to achieve additional energy efficiency. After meeting the selected compliance pathway of the IECC, all homes must also select one of the additional energy efficiency packages listed below:
Package #1 Enhanced Envelope - 5% than Prescriptive UA values
Package #2 HVAC – One of the following: 95 AFUE Furnace/16 SEER matchup
10 HSPF Heat Pump/16 SEER matchup
Package #3 Water Heating – One of the following: • .82EF (i.e. Tankless) Water Heater
• 2.0EF (i.e. Hybrid/Heat Pump) Water Heater
• Solar Water Heating System
Package #4 Duct System – One of the following: • 100% of ducts and air handler in thermal
envelope
• 100% ductless (i.e. mini split) thermal
distribution system
• 100% of ducts located in conditioned space per R403.3.2 (i.e. buried ducts)
Package #5 Air Sealing + Ventilation – 3ACH50 with ERV or HRV installed
The following have been in the code with a few changes:
Other significant changes within the 2021 IECC:
R402.4.1.2– Blower Door Testing
5 ACH50 is now the maximum allowed blower door leakage rate in all climate zones. This is great news for Climate Zone 3 (CZ3) jurisdictions, however, 3 ACH50 is still the prescriptive leakage rate for CZ 3. Additionally, exemptions from blower door testing are now allowed for conditioned garages (attached or detached) if they meet the air sealing details listed in Table R402.4.1.1. What to consider here: While the infiltration rate has increased for CZ3, the reference home maintains an infiltration rate of 3ACH50. So if you build a home in CZ3, you are allowed to comply with code 5ACH50, but the reference home is still lower and you are having to trade off against this higher result.
R403.3– Ducts
R8 Duct insulation is now required for HVAC supply and return duct runs (3 inches or more in diameter) outside of conditioned space. It is no longer a prescriptive measure as stated in 2015/2018 energy code editions, R6 duct insulation is still allowed for ducts smaller than 3 inches in diameter. Unless all HVAC ducts and air handler equipment are located inside of conditioned space, homes pursuing the Total Building Performance or Energy Rating Index pathways will need to incorporate R8 ducts to demonstrate compliance.
R403.3.5– Duct Testing
Duct leakage testing is made mandatory for all homes, including those with ducts and equipment in conditioned spaces. Targets are set at 4% for homes with ducts outside of conditioned space, and 8% for those in conditioned space.
R403.6– Whole House Mechanical Ventilation and Testing
Whole House Mechanical Ventilation efficiency requirements have increased significantly according to Table R403.6.2. This all but eliminates the ability to use an ‘AirCycler’ system that utilizes the air handler motor and damper to deliver fresh air.
Mandatory EV Requirements (from the City of San Antonio Website):
SECTION R409 PHOTOVOLTAIC (PV) CAPABLE This section applies to detached one and two- family dwellings and townhouses three stories or less above the grade plane. R409.1 Electrical service reserve space. The main electrical service panel shall have a reserved space to allow installation of a dual pole circuit breaker for future
solar electric installation and shall be labeled “For Future Solar Electric.” The reserved space shall be positioned at the opposite (load) end from the input feeder location or main circuit location.
SECTION R410, ELECTRIC VEHICLE (EV) READY, and Section R410.1, Electric vehicle ready, are added as follows: SECTION R410 ELECTRIC VEHICLE (EV) READY
This section applies to detached one and two-
family dwellings and townhouses three stories or less above the grade plane. R410.1 Electric vehicle ready. One and two-family dwellings, and townhouses three stories or less with a garage shall have a dedicated 40amp/240volt single receptacle for EV use.
These are just the highlights of the changes we are available to assist you in finding the best solution for your company.
www.burgess-inc.com