Of course, there is one situation in which libertarians countenance forcible restriction of property development or use without any contractual agreement. That is the case where the development or use of property is itself an aggression against another person or their property — that is, where a particular property development or use violates the property rights of another. This can occur in cases where a development or use of property produces excessive pollution or noise to surrounding properties or invades their space. Thus, opening a coal-fire power station or an oil refinery in the middle of a residential neighborhood may legitimately be prevented by residents, since the pollution would involve a violation of their property rights.

Force may legitimately be used only to prevent actual property invasions by others and not merely to prevent noninvasive actions that detrimentally impact upon our enjoyment of our property. For example, in the absence of some voluntary restrictive covenant, there is no inherent right to prevent one’s neighbor from keeping a car body in his front yard or painting his garage an unsightly color. This is the case even if the aesthetic distaste for this ugliness is widespread, such that it impacts the market value of adjoining properties — there is no such thing as a right to preserve the value of one’s property, only its physical integrity. Moreover, this is true regardless of whether one is speaking of the objective market value, the subjective value to the property owner, or any other measure of value. People are entitled to protect the integrity of their property from invasive acts by others; they are not entitled to forcibly prevent legitimate acts by others merely to protect the market value of their property.¹

1. Ben O’Neill – How Zoning Rules Would Work in a Free Society [↩]