This chapter addresses the ethical considerations of conducting experiments involving human participants. It explains Institutional Review Board (IRB) requirements, informed consent, and protections for participant welfare. Architectural experiments often involve vulnerable populations or emotionally charged environments, making ethical diligence critical. Case examples highlight how to balance research goals with participant safety, privacy, and autonomy. The chapter also discusses data handling, transparency, and ethical reporting. Adhering to these principles ensures that experimental research is both responsible and credible.