ASHRAE 90.1-2016 & BPF

Yes, there have been a handful of LEEDusers posts regarding the changes in PRM results from 90.1-2013 and prior to 90.1-2016 and post with the latter's use of the 2004 stable baseline. 
  It's worth noting that the averaged code improvement from 2010 to 2016 is close to 15% averaged across building types and climate zones. So a 20% change in savings isn't outside the realm of code improvements from the two standards. But that 15% was the basis of the 2024 Energy Update which was reduced due to voters' inputs. 
  The body of knowledge is growing but flaws with the BPF method are known to some degree. PNNL has been made aware of some users' concerns and CMP was submitted to the 90.1 committee last June. 
 
USGBC can elect to make changes but ASHRAE lacks a means modify anything but the current version of 90.1. So this is something you can raise to GBCI and collectively you can provide more specifics on your project so we as an industry can learn more about issues with the calculation methodology. Note: LEED has other workarounds using v4 or v4.1 for electrification, other metrics and prescriptive ACPs which are available to your project.
   

Hi, I am new to PCIt and BPF calculations. Just out of curiosity, if the PCI is greater than the PCIt, what changes would you make in the energy model to bring it to the required level or point? Thanks, Pramod

Pramod,
That's a hard question to summarize for all buildings in all climates. It might as well be asking about any proposed energy model and a notional baseline. But some of the quirks with the newer PRM method include the natural gas baseline in climate zones outside 1A-3A. And the fixed 2016 US national average utility rates from then of $1.00/therm and $0.1013/kWh which create a ratio that is embedded in the BPFs, which may have escalated but are yours locally quite different?

These are some of the first things to check: is your baseline gas or electric? Is your proposed gas or electric? Are the rates in 90.1 a similar ratio to yours? Is your building type represented by a reasonable approximate from one the 16 DOE prototypes, which are then boiled down to the BPFs? These are the things going into a 90.1-2016 or later PRM model to know what to expect and why you might want to punt to v4 vs v4.1 and use the 2024 Energy Update which is quasi-equiavlent to v4.1. 

For further reading check out:
https://www.energycodes.gov/sites/default/files/2024-06/Commercial_Prototypes_ASHRAE901-2019AppGPRM.pdf
The BPF values for “All others” are developed for each climate zone except 0A, 0B, and 1B using weighted average values for each prototype building using national construction weights (Lei et al. 2020). For 0A, 0B, and 1B, straight numerical averages are used instead since those climate zones do not exist in the U.S. and there are no national construction weights

We have found significant (and challenging) differencies between calculations under ASHRAE 90.1 2010 and 2016 working for LEED v4.1 projects. A few exemples: - ID + C Whole Office building: % Cost Improvement under 90.1 - 2016: 5.2% % Cost Improvement under 90.1 - 2010: 33% - ID + C Office building (3 floors): % Cost Improvement under 90.1 - 2016: 13% % Cost Improvement under 90.1 - 2010: 34% - BD + C Emergency response building: % Cost Improvement under 90.1 - 2016: 30% % Cost Improvement under 90.1 - 2010: 48% In our experience, what has a more powerful impact is the contribution of renewable energy, more than energy conservation measures for the proposed building, that has less impact due to the effect of the BPF in the calculation of the percentatge of improvement. What we found most "annoying" from the new calculation methodology is the relative difficulty to predict the behaviour of the formula, taking into account the weighting of the unregulated loads in both the PCI and PCIt metrics.

Hi all, We recently worked on a New Construction (NC) project in India and observed a significant difference in energy cost savings when comparing ASHRAE 90.1–2010 vs 90.1–2016 baselines.

• % Cost Improvement under ASHRAE 90.1–2016: 6%
• % Cost Improvement under ASHRAE 90.1–2010: 36.7%

These figures are similar to what Manuel observed in another thread. I would appreciate it if anyone could share specific and quantifiable energy strategies that helped achieve better savings—particularly in Climate Zones 0 and 1, where we've seen challenges meeting the required Performance Cost Index targets. Additionally, are there any exceptions or alternate compliance paths under LEED when using PCI-based calculations in these warmer climate zones?