On the FAQ of this page the following is written:
How does the LCA consider operating energy? Isn’t that going to be the biggest source of environmental impacts?
Depending on the materials selected, the lifespan of the building, and its performance, operating energy can have much higher life-cycle impacts than construction or demolition. While the reference standard for this option does include this end use, the LEED credit does not—and it’s because you’re already receiving credit elsewhere in the LEED rating system for reducing operating energy. The scope of this credit is only focused on impact reductions from building materials.
On the reference guide however, the operating energy performance seems to be included in the life-cycle assessment:
"The baseline and proposed buildings must be of comparable size, function, orientation, and OPERATING ENERGY PERFORMANCE as defined in EA Prerequisite Minimum Energy Performance"
Am I misreading it?
Second question. As written above, the operating energy performance is defined in EA Prerequisite Minimum Energy Performance. Does it mean that both the baseline and proposed building should operate as a minimum compliant building per the EA prerequisite? It makes more sense to make the baseline operating energy equal to the proposed building in my opinion.
Paula Melton
Editorial DirectorBuildingGreen, Inc.
LEEDuser Moderator
183 thumbs up
September 14, 2016 - 9:35 am
No, you're not misreading it! The point of this credit is to characterize embodied impacts of materials. Energy use is already covered in the EA section, so it's up to the design team to optimize for both at the same time. There is no overlap because that would double-count energy optimization.
Charalampos Giannikopoulos
Senior Sustainability ConsultantDCarbon
84 thumbs up
September 14, 2016 - 9:46 am
Hi Noriko,
we had similar doubts in the past and after a comprehensive communication with USGBC it was stated that "the intent for the MR Credit: Building life-cycled impact reduction is to encourage adaptive reuse and optimize the environmental performance of products and materials. The energy consumption of a project should be irrelevant. The baseline and proposed buildings must serve the same programmatic function, and must meet EA prerequisite Minimum Energy Performance by adhering to the requirements of ASHRAE 90.1-2010, Appendix G, Opaque Assemblies, Vertical Fenestration, Skylights, and Roof Solar Reflectance and Thermal Emittance sections."
Eventually, and after not addressing energy usage in the LCA model (as this was addressed in the corresponding EA prerequisite) we did manage to earn the credit for a v4 project.
Noriko Nagazumi
Woonerf Inc.74 thumbs up
September 15, 2016 - 2:52 am
Thank you Paula and Chalampos!
So, we are not counting the daily energy usage, just the impact of the
buildng materials, right?
The baseline building would be a minimum compliant EA minimum energy performance prerequisite building, while the proposed building would be itself because it meets ASHRAE's 90.1-2010 Appendix G.
Charalampos Giannikopoulos
Senior Sustainability ConsultantDCarbon
84 thumbs up
September 15, 2016 - 9:10 am
Correct, it' all about materials. Energy is covered under EA.
Dionisio Franca
DirectorWoonerf Inc.
30 thumbs up
October 19, 2016 - 1:39 am
Hi Charalampos,
I've got a follow up question on how to interpret USGBC's wording on using ASHRAE 90.1-2010 for the creation of the baseline.
When deciding on what materials should go on the baseline building for LCA calculations, are we free to choose between ASHRAE's table 5.5-1-8's "assembly maximum" or "insulation minimum r value"?