21-1203 Establishing a baseline EUI - Lab Building

QUESTION

The project is pursuing the Living Building Challenge Energy Petal. The proposed building is a 500,000+ SF mixed use building with laboratory, office, amenity, clinic, and retail spaces. The traditional method of calculating an EUI baseline using the AIA 2030 Zero Tool does not seem appropriate for this project due to the lack of a laboratory building option.

As a substitute to the Zero Tool and in congruence with feedback from the ILFI team, the design team proposes using the average EUI of a representative subset of buildings found in the I2SL Laboratory Benchmarking Tool. Appropriate filters were applied to the dataset and a resulting subset of 30 buildings with an average site EUI of 215 kbtu/sf-yr was used as the representative sample. A screenshot of the applied filters and resulting dataset is attached on the subsequent page. A 70% reduction from this baseline EUI of 215 results in a target site EUI of 65 kbtu/sf-yr. The design team proposes that 65 kbtu/sf-yr be the criteria for meeting the Energy Performance Requirement. We believe that this an aggressive, but practical target and we are excited about the opportunity to meet it.

ANSWER

The project team provided follow-up information clarifying that the originally proposed baseline and target EUI reflected data from buildings that had a ratio of lab to non-lab spaces (10%-30%/90-70%) comparable to that of the project (20%/80%). It also calculated a more customized weighted average using the I2SL baseline data from buildings composed of 90-100% lab for the lab portion of the project, and data from the ZeroTool for each type of non-lab space in the project. This customized weighted average resulted in a target EUI of 58 kbtu/sf-yr.

The project team additionally proposed that both approaches are valid, and requested to split the difference between the two results and use a target EUI of 61 kbtu/sf-yr. With the clarity provided regarding the original application of the I2SL baseline data, the Institute agrees that the original approach was valid. The Institute also agrees that both approaches are acceptable and acknowledges that while the more carefully apportioned weighted calculation may be more precise, because of the mix of databases, it may not be more accurate. The project team may use either of the proposed target EUIs: 65 kbtu/sf-yr or 61 kbtu/sf-yr, but must declare which at the time of the Ready Audit. 

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