Hi all,
Given the number of variables that have changed between v4 and v4.1 Optimize Energy analysis protocol, I am uncertain how to accurately preface the likely impact / rigor involved when providing project stakeholders an orientation. I understand the myriad of project specific variables make it impossible to provide a standard answer, but I'd like to "generally" prepare them for the realities ahead.
For example, the DOE Energy code Determination reports (https://www.energycodes.gov/development) appear to estimate an ~18% increase in efficiency/rigor between 90.1-2007 to 2010, another ~7-9% increase from 2010 to 2013, and another ~7-8% increase from 2013 to 2016. Using very rough math, this would seem to suggest a >30% increase in rigor (average across bldg types/climate zones) from 90.1-2007 (LEEDv3 project metric) to 2016 (LEEDv4.1 project metric)?
Per related LEEDv4 EAp2 post https://leeduser.buildinggreen.com/forum/leed-v41-ashrae-901-2016 , I understand the overall 90.1-2016 Appendix G comparative baseline criteria to be less stringent than that for v4? (similar to 90.1-2004 prescriptive values, resulting in a more standardized baseline / benchmark going forward). This would theoretically seem to make calculated higher performance less grueling for a Project design? But maybe not if EEMs successfully used in v3 and v4 projects are now mandatory provisions, thereby narrowing the options for engineered efficiency enhancements?
Similarly, I am curious if demonstrating mid to high performance under the new v4.1 PCI & GHG metrics requires project designers to "dig deeper", or perhaps necessitates installation of renewable energy system(s) in projects with higher process loads.
For example, what type of adjustments in approach is it requiring to ensure >30% PCI and GHG emission reduction success in a typical mid-size administrative office building? What about a building with 50+% process loads?
As such, I am hoping someone with a completed/approved v4.1 energy model can provide some feedback.....
Ultimately, any feedback is welcomed (e.g., "we thought our "typical" LEED efficiency design approach for a <Building type> would qualify for 30% but were surprised it only got us to 15%, therefore we did X, Y, Z to reach our specific Project's performance target")
Thanks for any insights!
Jamy Bacchus
Associate PrincipalME Engineers
16 thumbs up
January 24, 2020 - 1:56 pm
Given the lack of users volunteering to switch from v4 to v4.1 for this specific credit in the past year, it may be a while before we have much feedback to report here. Those who have internally done the analysis are encouraged to share their findings!
daric adair
3 thumbs up
December 1, 2020 - 9:18 am
Reviving an old thread. We have evaluated a few different buildings to try to determne this exact thing. The results? Pretty poor, with significant point loss. Best example is a LEEDv4 project achieve 47% Savings / 17 points; flipping to LEEDv4.1 results in 3 points. Project details: CZ4a, high performance envelope, optimized exterior window shading, LED lighting & advanced controls, VRF HVAC with decoupled ventilation and energy recovery. This is one example of multiple where LEEDv4/2010 savings are reasonible/reflective and the LEEDv4.1/2016 target appears well out of range. We've purposefully stuck to LEEDv4 as a result. Time is now running short as more AHJ's adopt 2016 codes, and as we revisit & do further studies, the results are still concerning. Slight hope that we're doing it 'wrong', but thus far the methods & math are checking out. Yes, we are concerned.
Eric Schlichting
3 thumbs up
July 28, 2022 - 9:09 am
Well, now I am concerned. I did not have a business reason to look into this 2 years ago but now I do.
I was working through a LEED v4.1 project today to see what it scored for the Optimize Energy Performance and I found the exact same thing that Daric Adair mentioned back in December of 2020. It is much harder to score points now that we are being asked to evaluate using the Performance Cost Index (PCI) and the Performance Cost Index Target (PCIt) for energy cost and greenhouse gas emissions.
My preliminary results found that a project posting 18.8% energy cost savings against ASHRAE 90.1-2016 App G Baseline is not close to scoring any points under LEED v4.1. I did some reverse calculations to learn that my particular project needed to score roughly 35% energy cost savings to even start scoring points given where PCI and PCIt were landing for me. Unfortunately, at this point, it might be hard to return to LEED v4 for this credit. Is that still possible in 2022? I am meeting a project manager today to discuss this situation and I am thinking of recommending that this project move to Option 2: Prescriptive Compliance: ASHRAE Advanced Energy Design Guide or even Option 3: System Optimization. That is if we cannot still use LEED v4.
I am glad this discussion is up on this website even though it is 2 years old. Does anyone else have any other thoughts or ideas that have worked through this in the past?
Since this discussion was posted, have others gone through the full credit calculation and discovered this situation for themselves? I was caught off guard for sure.
Marcus Sheffer
LEED Fellow7group / Energy Opportunities
LEEDuser Expert
5792 thumbs up
August 2, 2022 - 5:30 pm
If you registered the project under LEED v4 you can use that version of these credits.
Ashish Nautiyal
3 thumbs up
September 12, 2023 - 2:49 pm
Hi, I was looking into it and I am facing the same challenge to get points under LEED v4.1. Even the proposed design is 20% better than the Baseline in terms of cost but when I calculate the savings based on PCI, there is no points at all under the LEED v4.1
Does anyone got any positive results? How we can achieve points under this credit?
Jamy Bacchus
Associate PrincipalME Engineers
16 thumbs up
September 12, 2023 - 4:09 pm
There are many reasons for the challenges to 2016's revised PRM with PCI and BPFs. As folks have noted, it is based on the 2004 Std creating a stable baseline for all future Appendix G in 2016, 2019, 2022 and going forward. The calculations are different than 2013 and prior 90.1 versions. The baselines are based on building type and climate zone, which puts nat gas as the baseline's fuel type in colder climates (CZ 4-8). The energy costs embedded in the BPFs are based on US nationalized values which were relevant circa 2015. If your location has utility costs with a different ratio to those in the BPF creation, then you might have a hinderance on all-elelctric or an easier time. ASHRAE has a tool to help pull out these embedded costs and replace them with your own regional costs. https://www.energycodes.gov/ashrae-standard-901-performance-based-compli...
I'm not aware of anyone submitting this to GBCI for acceptance in asking to use modified BPFs based on local rates, but I would hope it would get accepted if done correctly.
PNNL has shared a pre-publication report which revised most of the BPFs in 2016 because they were created based on a nearly complete 90.1-2016. Having gone back and re-running them against the published versions, they found some warranted adjustments--most of them were small except "warehouses". But when we're getting zero or near-zero savings, then these incremental benefits are worth leveraging. TBD on the date the world will see this.
I think there are a few things to keep in mind like trying EApc160 and EApc161. You can demonstrate EAp2 compliance using 90.1-2016's ECB path! Then you can use EAc2 and maybe you're not getting much in energy cost savings, but I would hope you see GHG reductions justifying the proposed design. And hourly forecasted electric grid emissions factors are available from NREL Cambium, so eGRID 2021 is not your only option. See LEED Hourly Cambium Demand Adjusted Energy Metrics Calculator.
Lastly, you can double or perhaps triple dip with any on-site renewables in that it can be used in the energy cost savings, GHG savings and RE power credits.
I encourage others to share their feedback.