Building science is the collection of scientific knowledge that focuses on the analysis of the physical phenomena affecting buildings. Building physics, architectural science and applied physics are terms used for the knowledge domain that overlaps with building science.

Building science traditionally includes the study of indoor thermal environment, indoor acoustic environment, indoor light environment, indoor air quality, and building resource use, including energy and building material use These areas are studied in terms of physical principles, relationship to building occupant health, comfort, and productivity, and how they can be controlled by the building envelope and electrical and mechanical systems. The National Institute of Building Sciences (NIBS) additionally includes the areas of building information modeling, building commissioning, fire protection engineering, seismic design and resilient design within its scope.