Answer : What are interior designers? Interior designers are responsible for designing the space where people live, work, and entertain guests. Designing the interiors of buildings is a huge business in much of the world because interior design affects comfort, lifestyle, safety, efficiency - all areas that affect productivity and leisure. It's rare to find a person that owns or occupies their own home who doesn't work with at least one professional designer. You might not use an actual "interior" designer to decorate your houses-you might need someone who specializes in painting or carpentry-but there's usually something about your home you'll want fixed up professionally once you start looking around.