To address this question for design professionals, code officials, and policy makers, Green Building United teamed up with Steven Winter Associates, Inc. with funding from the Sustainable Development Fund to create a crosswalk document that demonstrates the relative energy performance of Philadelphia’s energy code to various beyond-code standards. The key metric of comparison is the energy model requirements but includes whether other elements of high-performance buildings are required.
To help navigate the document, we’ve compiled answers to some frequently asked questions below.
Why is the baseline ASHRAE 90.1-2013 instead of ASHRAE 90.1-2016?
Some beyond-code standards use statewide code as its baseline to ensure that it keeps up with code changes, including ENERGY STAR. The Commonwealth of Pennsylvania is currently on ASHRAE 90.1-2013 so we’ve used this baseline for our comparison.
Compliance Philadelphia’s current code 2018 IECC/ASHRAE 90.1-2016 itself requires an 8% improvement over ASHRAE 90.1-2013. The minimum certification requirements for energy performance for LEED BD+C, LEED Midrise, National Green Building Standard, Green Globes are all lower than Philadelphia’s current code. ENERGY STAR Multifamily New Construction, LEED Lowrise, Enterprise Green Communities, and PHIUS all require better energy performance than Philadelphia’s current code.
Presented another way, the graph below demonstrates the relative energy performance of each standard as compared to Philadelphia’s current and previous code as well as Pennsylvania’s current statewide code.
What is the percent difference between current code and the most recent former code - 2009 IECC /ASHRAE 90.1-2007 - in Philadelphia?
The three code cycle jump represents an increase of 33% in energy performance.
What version of LEED is evaluated in this crosswalk?
LEED v4 was used in this comparison document. LEED v4.1 is still in beta version.
Why is there a difference in minimum performance for LEED Lowrise vs. LEED BD+C and LEED Midrise?
Unlike LEED BD+C and LEED Midrise, LEED Lowrise must comply with the minimum requirements of ENERGY STAR, which is about a 15% performance over an ASHRAE 90.1-2013 baseline.
What about different certification levels for each standard?
We used the base level of certification for each beyond-code standard featured in this comparison. While many of the beyond-code standards have higher levels of achievement, there are often ways to achieve higher levels without improving upon energy performance. Without an explicit minimum energy performance requirement for each subsequent level, we could not reasonably include this in the analysis.
What’s the key takeaway from this comparison?
Philadelphia’s energy code is more stringent in its base energy performance than the base certification requirements for some beyond-code standards. While this does not take into account all of the other elements of high-performance building that are encompassed in these standards, Philadelphia’s new and renovated building stock is more energy efficient than ever.
What’s more, projects that meet Philadelphia’s energy code and are also pursuing beyond-code standards with lower minimum energy performance requirements have the potential to earn extra credits or points simply by complying with code.
Where can I learn more?
Green Building United held two in-person sessions to review this crosswalk - one geared toward market-rate commercial construction and one geared toward affordable multi-family housing.
Slides from the event with additional detail are available from both the market-rate and affordable housing sessions.
Videos of each are available in our on-demand webinar library with several other educational sessions Green Building United has held to help support energy code implementation in Philadelphia. These resources are made possible through the support of the Sustainable Development Fund.