Empire-building is the practice of attempting to obtain greater power and authority within an organization for the purposes of self-aggrandizement, particularly by having extra staff or subordinates.
In political science, empire-building refers to the tendency of countries and nations to acquire resources, land, and economic influence outside their borders in order to expand their size, power, and wealth. This expansion can be at the cost of those nations or people that have had resources taken away from them so that the conqueror can be enriched.
In business, empire-building is demonstrated when individuals or small groups attempt to gain control over key projects and initiatives to maximize job security and promotability. Project leadership hoards potential credit and prestige the project can produce. Because this approach prevents other people in the organization from contributing in a meaningful manner and alternative or competing projects to address the project's goals are destroyed regardless of their merit, the company suffers as a whole, projects fail, and the goals of the project are achieved partially, inadequately, or not at all. This sort of behavior is supposed to be stopped by upper management but is nevertheless very common.
In an organization, empire-building can also be demonstrated when an individual or small group eagerly and proactively suggests and pursues functions, activities or projects that are of questionable value to try to enhance legitimacy and future value. Pursuit of these activities is initially done at marginal cost, but later the activities are used to justify increased resource allocation, being part of the organizational status quo, and thus the individual or group's overall command of resources, and influence, increases.