For WELL Core Certification, which focuses on the base building elements of a project, a certain portion of the total building floor area must be designated for performance testing to ensure the building meets WELL's health and wellness criteria. The requirement of a minimum of 2,500 ft² (approximately 232 m²) for performance testing is established to ensure a representative sample of the building's overall environment and operational practices. This area must be readily accessible for testing and capable of demonstrating the building's compliance with WELL's standards. This requirement underscores the WELL Building Standard's commitment to evidence-based outcomes and verifiable performance, ensuring that the building's core and shell support the health and well-being of its future occupants.