Linnean provided Passive House consulting services for the 25 Dukes Road single-family home located in Nantucket, MA. Designed and built by Chuck Lenhart, this 3-story, high-performance, and airtight (0.03cfm50/ft2) home has the potential to be the first project utilizing double-hung windows to be certified by PHIUS. As the Certified Passive House Consultant (CPHC), Linnean Solutions not only provided Passive House design support for the project team, but also prepared the PHIUS+2018 WUFI energy model and managed the submission and review process necessary for pre-certification.