How to Design a Barn Cupola

The cupola is an architectural feature appearing in architectural styles from Greek and Roman to Islamic. Cupolas are a roof focal point on religious buildings, government buildings, barns and homes. NASA is even designing a cupola for the space station so astronauts can sit and look out when working.

After the U.S. Civil War, the barn cupola's popularity grew. Historically, a barn cupola is rectangular and allows light and ventilation into the barn, helping keep the hay dry, venting built-up heat, and improving air circulation.

Today, there are many options for designing a barn cupola.

  1. Design a cupola sized for your barn. The general rule of thumb for appropriate sizing of a cupola is to build it 1 inch to 1.25 inches for every foot of unbroken roof line. For example, if the roof is 30 feet long, the cupola should be between 30 and 37.5 inches long. Of course, if this is an old barn, or the cupola you desire to install is extremely heavy, you may want to check with an architect or structural engineer to determine if the roof can handle the weight.

  2. Determine how many cupolas you need. Most barns have just one but some use two or more. Multiple cupolas make a nice design and allow more light and air to circulate. You may design a slightly smaller cupola if you are using multiples. Another option is to use one large cupola in the middle and two smaller ones, one at each side.

  3. Determine the basic design of the cupola desired. Decide whether it should have four, six or eight sides. Decide whether you to add vents or windows in the cupola. Even on a barn, builders often create interesting window designs in cupolas. Some get even more creative, perhaps creating a bird house within the cupola.

  4. Choose your materials. Typically, cupola bodies are comprised of vinyl or wood. The roofing materials are generally cedar shakes, asphalt shingles, vinyl roofing or copper.

  5. Create the finishing touches. Many people top their barn cupolas with weather vanes, spires or finials. The eagle, rooster and horse are common design elements for weather vanes, but there are no limits to how creative you can be -- designs range from traditional to whimsical. There are many options available in a variety of materials for cupola toppers. Be sure to purchase the mounting hardware to safely secure your topper to the cupola. All hardware should be in proper proportion given the size of the cupola.

  6. Consider adding molding. Pre-made cupolas may come with molding built on. If you are making your own cupola, look at the style of your barn and home. You may wish to replicate the design elements of your existing buildings on the cupola.


  • Keep everything in proportion. Put a large cupola or cupolas on a large barn and small ones on small barns or garages. Make sure the weather vane or finial is appropriately sized for your cupola.
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