To present the process used by a clinical laboratory to guide the design of their new facility, part of a major campus expansion at a pediatric hospital. The primary objective was to generate information about arrangement and allocation of laboratory space and functional flows in the early phases of the expansion project. Seattle Children's Hospital has increased the capacity of their primary campus in response to growing demand for specialized services. The clinical laboratory was identified as one of the functional groups that would move their operations to the new building. The clinical laboratory team agreed on a three-stage process to guide the development of their initial design specifications: formulate the concept, develop design alternatives, and evaluate those alternatives. The different tasks were executed successfully. The process defined-based on Plan, Do, Check, Act (PDCA)-provided a context for collaboration among sections of the clinical laboratory, reducing silo thinking, so common in the specialized sections within a large clinical laboratory. The process was developed to guide the lean design efforts, even when initial space and location parameters had not yet been decided and was sufficiently flexible to accommodate changes in the project constraints and emergent information generated by the concurrent design activities of other hospital functional groups to be included in the campus expansion. The three-stage process allowed the team to review each laboratory section's complexity, create multiple conceptual designs for review, and ultimately increase the likelihood of an efficient physical configuration that would satisfy a diverse group of stakeholders.