Chinedu Moneke, PE
May 6, 2021
Decisions, Decisions: Choosing the Best Multifamily NGBS Energy Efficiency Compliance Option
There are many benefits to energy-efficient buildings. For multifamily buildings, these include lower operating costs for common areas, eligibility for preferred financing incentives, higher valuation on resale, greater marketability of the building to renters, lower utility bills, better quality, and increased comfort. When it comes to residential energy efficiency, there are basically two options for demonstrating energy compliance to the National Green Building Standard ICC-700 (NGBS): the Prescriptive and the Performance.
Multifamily developers interested in pursuing NGBS Green certification will often ask which energy compliance option is best. Below, I explain the two compliance options to help you decide which one is best for your next project.
NGBS Prescriptive Option:
The Prescriptive option is like a recipe. It provides the designer with a series of building component thresholds that must be met or exceeded to demonstrate compliance. Common prescriptive measures include minimum R-values for insulation or wall assemblies, acceptable infiltration rates, and efficiency requirements for mechanical systems, such as water heaters and HVAC equipment. The architect or builder designs the home to meet the Prescriptive option requirements and then an accredited NGBS Green Verifier must inspect the home to confirm compliance by verifying that the efficiency items on the list have been successfully included in the home.
When to Use:
- The Prescriptive option is best suited for buildings pursuing NGBS Bronze or Silver level certification because it is simple and straightforward.
- Builders who are new to green, high-performance construction techniques might also find the Prescriptive option an easier starting point.
The NGBS Prescriptive options include the following pathways:
| 703 (Prescriptive Path) |
Y |
Y |
Bronze &
Silver |
Most affordable |
701.1.4 (Alternative Bronze -
ICC IECC or IRC Chapter 11) |
N |
Y |
Bronze |
COMcheck documentation needed |
701.1.4 (Alternative Silver -
ICC IECC - Tropical) |
Y |
Y |
Silver |
COMcheck documentation needed |
The 703 Prescriptive Path is the most affordable NGBS Prescriptive option because there is no mandatory COMcheck documentation, which can incur additional time and cost.
NGBS Performance Option:
The Performance option has fewer mandatory practices than the Prescriptive option. The Performance option allows a builder to make efficiency tradeoffs between components rather than having a fixed list of required components. Instead of a checklist of mandatory practices or systems, this option sets an efficiency baseline above the minimum building code. The Performance option supports creativity because it includes more design options. The builder demonstrates the home’s compliance by using energy modeling software to show that the annual energy performance is better than, or at least equal to, that of a building built using the prescriptive IECC or IRC code. The Performance option is the only way a home can earn the Emerald certification level.
When to Use:
- When the local jurisdiction or affordable housing program specifies modeling and testing as part of their compliance measures.
- For homes pursuing the Gold and Emerald certification levels. The Performance option should be used in these cases because Verifiers use the energy modeling tool to evaluate various combinations of design strategies, components, and technologies until they arrive at a design solution that provides the greatest energy savings for the least cost.
- To help with getting an ENERGY STAR score when trying to meet HUD financing requirements.
- To set a baseline for post-occupancy benchmarking.
- For homes also pursuing ENERGY STAR certification or the HERS Index rating, the Performance option should be used for all certification levels, including the Bronze and Silver, because an energy report is required for those programs and can be used to satisfy the NGBS’s energy requirements, thereby saving time and additional cost.
- For homes that encounter limitations in meeting the Prescriptive option threshold(s). Efficiency tradeoffs between components can be used to demonstrate compliance.
- For homes who prefer to use a different cost-effective approach for code compliance.
- For homes using renewable energy. This would be a good tradeoff when conducting an energy analysis on the home with the energy modeling software.
The NGBS performance options include the following pathways:
| 702 (Performance Path) |
Y |
Y |
Bronze
Silver
Gold &
Emerald |
Most affordable. Energy performance report needed. |
| 704 (HERS Index Target Path) |
Y |
N |
Bronze &
Silver |
Confirmed HERS report needed. |
| 704 (ERI Target Path) |
N |
Y |
Bronze
Silver
Gold &
Emerald |
Affordable. Confirmed ERI report needed. |
| 701.1.4 (Alternative Bronze/Silver - ENERGY STAR |
Y |
Y |
Bronze &
Silver |
Use only when also pursuing ENERGY STAR. ENERGY STAR certification and report needed. |
The “Alternative Bronze/Silver” path should only be used when also pursuing ENERGY STAR, because additional reports and confirmed ratings might be needed, which can incur extra costs. Only the energy modeling report is needed for the 702-performance path.
The NGBS Green certification program provides builders with multiple energy paths for achieving energy compliance for their home’s certification.
Architects, developers, and building owners are encouraged to hire an accredited NGBS Green Verifier during the design stage to help pick the most cost-effect compliance path. Verifiers can be found on our Find a Verifier page. Project teams can download the free NGBS Green Scoring Tool to help them decide which compliance path is best for their particular project.
For more information or direction on which path best suits your project, please contact us.
** The NGBS 2020 Chapter 12 Certified Path energy compliance will covered in more detail in a future blog.
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