When most people think of an office building, they think of glittering towers made of windows on every side. But those offices are more than the outer surface area that is exposed to natural light. Inside any decently-sized office building are a large number of offices and other spaces that have no windows at all. Even skylights are out of the question for floors that are not at the top. Architects have done their best, but it's up to building owners and occupying businesses to make those interior windowless offices actually enjoyable to work in.