How to document thermal comfort in incomplete spaces within the project

Reference the LEED BD+C Reference Guide Overview section for Incomplete Spaces. https://www.usgbc.org/guide/bdc

"For incomplete spaces in projects using a rating system other than LEED BD+C: Core and Shell, the project team must provide supplemental documentation.

• Submit a letter of commitment, signed by the owner, indicating that the remaining incomplete spaces will satisfy the requirements of each prerequisite and credit achieved by this project if and when completed by the owner. This letter may cover the commitment in general terms and need not address each prerequisite or credit individually.
• For incomplete spaces intended to be finished by tenants (i.e., parties other than the owner), submit a set of nonbinding tenant design and construction guidelines, with a brief explanation of the project circumstances.

For prerequisites with established baselines (e.g., WE Prerequisite Indoor Water Use, EA Prerequisite Minimum Energy Performance) and the credits dependent on the calculations in the prerequisites, the proposed design must be equivalent to the baseline for the incomplete spaces. Project teams that wish to claim environmental performance or benefit beyond the baseline for incomplete spaces should refer to the Tenant Lease and Sales Agreement section."

Please take a look at LI 10102. It explains that you need to provide a Letter of Commitment and possibly Tenant Design and Construction Guidelines, depending on the overall project details.