One of your toughest decisions - but many people feel the most fun - you'll make when building your barn is the style. There are many to choose from and each style can have modifications. Things to consider are the style's suitability to your climate, the function or "flow" of your horse work and, of course, your budget. The amount of time you can wait for a new barn is also a factor. A modular barn can be erected in a few days, while a pole barn building can take months.
A Pole Barn (Post Frame) framing utilizes posts and beams to minimize the number of framing elements in walls. It is economical, strong and relatively simple to build, making it the most popular framing method for custom barns. A pole barn frame consists of 6- to 8-inch round or rectangular pressure-treated wood posts set 3 to 6 feet below the ground. Poles are typically set at 8- to 12-foot intervals and rest on a pad of concrete at the bottom of each hole. Poles and trusses or rafters are generally visible inside the barn. Pole barns are easy to build in part because they require no trench work for a foundation, only holes; and these can be dug using a tractor auger or a hand posthole digger.
A Timber Frame (Post and Beam) is another type of post and beam construction, but rather than plugging into the ground like a pole barn, a timber frame barn sets on a concrete foundation. A properly constructed timber frame is incredibly sturdy--some have lasted for hundreds of years. It is typically comprised of 8- and 10-inch square timbers for main members and smaller timbers for roof purlins and floor joists. Major joints are traditionally dovetails and mortise and tenon, often hand cut and secured with wooden pins, like fine furniture construction on a larger scale. Craftsmen using traditional timber frame methods don't use nails or other metal fasteners unless they are required by local codes. Timber frame barns are sometimes built in or near the builder's shop and shipped to the site to be erected by the builder, a local contractor or the owner. Timber-frame kits that use metal connectors to secure joints are available
Modular barns generally consist of a steel framework with steel-framed panels fitted in between. The panels are typically comprised of a plywood or OSB (oriented strand board) core with sheet steel laminated to the inside surface and steel, wood or other siding material laminated to the outside surface. An advantage of this framing is that damaged panels can be replaced relatively easily. Some modular barns have a "warehouse" appearance, but many manufacturers offer a variety of styles, siding and roofing materials. If you don't see a plan you like, most manufacturers will modify an existing plan to suit your needs. Modular barns generally go up quicker and with less expense than custom barns. They are especially fire resistant because of the steel framing and steel-skinned wall panels.
A shed row barn is the most common type of modular (or prefabricated) barn. It is a good choice for warm climates as they maximize air flow and ventilation. They can vary in the size of the overhand and can be configured in a straight line, an “L” shape or a “U” shape, depending on the number of horses and your work flow. Shed rows is also an option for colder climates, but consider enclosing the overhand area and adding insulation to the walls and roofing. Shed row barns have a shed or pitched flat roof. The shed roof is all one plane and is often used for three-sided shelters or small stables. It is also commonly attached to the eaves of an existing gable roof or to the wall of a barn.
One pole barn (or post-frame) style is called the Full Monitor or Raised Center Aisle barn. It has a high center raised roof that lets hot air rise above the stalls and horses. The design also allows skylights and windows to be installed on each side of the center roofline, letting in more light and additional fresh air. The monitor has essentially two shed roofs with a gable in the middle. This is good for long rows of stalls.
Another popular pole barn style is called the Gambrel. It offers the benefit of a large loft located above the stalls for added storage. The Gambrel has a double-pitched roof popular on two-story barns having a second floor because of the increased headroom and useable floor space it allows. Gambrel trusses eliminate the need for interior post and beam supports, which allows you to create any floor plan you wish.
Take some times to fully consider what type of barn best suits how you intend to care for your horses. They each have pros and cons - in the end, it will be up to you.