Building science studies how heat, air, and vapor flows interact with building enclosure layers.
Building science is an integrated blend of technical disciplines, including physics, chemistry, biology, climatology, and even ecology. It involves understanding everything from molecules and materials to mock-ups and models. Deep understanding and integration of all these disciplines takes time; maybe that is why many of our building scientists are on the mature end of the spectrum.
Sometimes you will hear “building physics” used interchangeably with “building science,” but building physics focuses only on the complex interplay of heat, air, and moisture flows within and across the building enclosure. Building science includes all this and adds people to the mix: it is the conditions occupants impose on the indoor environment that complicate the science of building performance. The best indoor temperature and relative humidity mid-winter for people is very different from what the exterior wall “prefers.” And just think how simple the perfect wall would be without any windows!
Building science is also more associated with the enclosure than with mechanical systems—HVAC, plumbing, and electrical—but building science requires understanding of mechanical systems and their effects on heat, air, and moisture flows. This allows potential issues associated with the interdependence of the enclosure, the mechanical systems, and the occupants to be foreseen and prevented (or diagnosed and resolved).
How do you know a building scientist when you see one? There is no clear answer. While we have a National Institute of Building Sciences (NIBS), we don’t have any certification or licensing associated with building science. There are licensed building engineers and architects who “qualify” as building scientists (though precious few, unfortunately), and there are an equal number of non-licensed building professionals who are recognized experts in the field of building science. It often falls to building scientists to point out problems and diagnose ills with conventional building materials and systems, making them industry gadflies, but ideally a building-science perspective contributes to integrated design, construction, and operations. It helps ensure that all systems work together as they should without causing unforeseen problems with moisture, durability, indoor air quality, or comfort.
Case in point: While most building professionals and code officials focus on vapor permeability just by looking at the dedicated vapor retarder and how it restricts the movement of moisture into building assemblies, building science turns this notion on its head, insisting that building professionals look at the vapor permeability of all layers of an assembly to ensure drying potential (more on this in subsequent primers).
Building science provides the language, framework, and systems thinking to make our buildings resource-efficient, comfortable, and durable in a changing environment with ever-increasing demands for efficiency and durability.