Machinery and air-handling systems can have many rotating components capable of transmitting vibration to the structure and on to senstive receivers in the space. Plumbing systems can also be the source of structural vibration due to fluid flow. These vibration problems can require a careful analysis of vibration sources and paths. Once these are identified, the solution can be various vibration isolators or mitigation systems. Below are some projects in which we addressed vibration arising from machinery and internal building systems.