Baseline EUI errors with EAp2 Case 2 Calculators?

David, I'm not sure how Target Finder is computing a baseline EUI for multifamily buildings, but in general Portfolio Manager, Target Finder, and the Case 2 calculator all make use of the CBECS database for national averages. One guess on why you are seeing such different values is that the calculator will be showing national average _source_ EUIs, and Target Finder may be reporting a _site_ EUI value.

Just a guess, but in any event I think there's no way to make the case for using Target Finder as a baseline in lieu of the calculator.

We've just submitted an Office project with a Source Energy Intensity of 248 and Energy Star Score of 76 according to the Portfolio Manager tool. This building is 26% more efficient than the National Average Source Intensity of 334 listed in the program and on the Statement of Energy Performance.

However while entering data into the Case 2 calculator for a different project which is a multi-use facility we noticed that the National Average Source Energy Intensity value for Office space was listed as 182, in yet another reference we saw that the Average Source EUI for office was 193. And in both Target Finder and Portfolio Manager it seems that the Natl. Average Source EUI for Office varies based on building specific factors.

Should this be occurring? To echo David above, any thoughts on why such discrepancies might exist?

Is this a valid concern concerning the accuracy of the Case 2 calculator for benchmarking non energy star eligible facilities?

Thanks for any insight anyone may have, we're certainly willing to share more details if needed for clarification as well.

Marc, What you're seeing is the effect of the various inputs that are used to adjust the baseline EUI according to significant normalizing factors. Energy Star has you add all the info about operating hours, occupancy, number of PCs, etc because those factors have been shown to be significantly correlated with consumption, and therefore play a role in the algorithm that sets the baseline for a given building and then produces a score against that baseline. This is how both Portfolio Manager and Target Finder are intended to work.

One of the (known) limitations of the Case 2 calculator is that no such adjustments can be made, but the problem is that these unique buildings landed in Case 2 because the body of data needed to produce a viable algorithm just doesn't exist. They fall outside of typical, and therefore it's really tricky to come up with statistically justifiable way to offer normalizing opportunities. The Case 2 calculator is not a perfect solution, but data limitations preclude better alternatives, at least for the time being.

As mentioned some comments down (or maybe it's in EAc1 thread), stay tuned for different options that are being proposed for 2012 (public comment period should be opening soon).

Jenny,

Thank you very much for your help in clarifying. As a follow up: currently space types entered in Portfolio Manager that are NOT eligible for an Energy Star score do not have the same algorithms applied. Correct?

If using the case 2 calculator clearly illustrates a building does not comply based on the space type characterization used, would a next logical step be cohort development for benchmarking to better understand if your building is inefficient or simply doesn't accurately fit into the space type you've chosen? Will cohort development always supersede the case 2 calculator, or does non-compliance in the calculator mean certification (at that time) is unachievable?

Again thanks for any insight. These forums are an invaluable resource.

Marc,

Regarding algorithms and not-ratable space types - my understanding is the same as your's.

And for your second question, I think the answer might be a little of both. Right now, building's that fall in Case 2, Option 1 but do not meet the requirements are more or less stuck, unless they can make the case that they are unique and should be allowed to benchmark against a historic baseline or comparable buildings (Case 2, Option 2).

We are working on a building type that is not eligible for an Energy Star score, and falls under Case 2 Calculator Option 1. The building's Source EUI is too low to meet the pre-requisite for LEED. However, we'd like to set some targets to see how much money, energy, and COe the building could save by acheiving these targets. I don't believe it's possible to set targets in Portfolio Manager or the Delta Score Estimator for Case 2 buildings - is this correct? Do you know of any other tool that would allow us to set targets for % above average for this building type and estimate savings?