You may not recognize the term, but you’ve probably seen this feature plenty of times on barns, sheds and houses. Characterized as a tower, or dome-like feature on the peak of a roof, a cupola is a popular choice to add character to a roofline. Some feature windows, stained glass, and often holds a weathervane.
You may have wondered what purpose these structures serve, given that in modern architecture, they are often closed off and inaccessible. Today, the modern cupola is mostly always just aesthetic. Meaning, it is not a functioning piece of the architecture. However, this was not always the case. Originally, the cupola was frequently used on barn roofs to add ventilation to tightly built barns. In the winter, fumes from cow manure, and breath from the cows would create an inhospitable moisture on the barn walls and ceiling, causing barn wood to rot prematurely. The cupola was used to add ventilation to the roof, which helped keep the barn wood from decomposing. Louver vents, or sometimes windows, allowed the hot moist air to escape from the barn roof. The cupola was also frequently used to add light into buildings, and sometimes even functioned as a looking point.
Today, most cupolas are not accessible from the inside, but many still have the characteristic windows that the original cupolas featured. If not originally designed when the house was built, there are even packages that can be purchased and installed on rooftops to add that extra bit of character.