Your city or county planning or zoning department has probably established zones for stores and offices (commercial zones), factories (industrial zones), and houses (residential zones). In some residential areas -- especially in affluent communities -- local zoning ordinances absolutely prohibit all types of business. In the great majority of municipalities, however, residential zoning rules allow small, non-polluting home businesses, as long as any home containing a business is used primarily as a residence and the business activities don't negatively affect neighbors.