Stables can be very unhealthy places for horses and one of the reasons for this is poor ventilation. While stable windows aren't the only thing that helps regulate the ventilation in a barn, they are very important. Windows of course, are also important for letting in natural light. A bright, airy barn is healthier for horses who must be kept in. Small dark spaces can be stressful for horses, so wide windows, through which your horse can see activity outside may help prevent your horse from becoming bored.

A barn with lots of natural light is also more pleasant for the humans that must work there too.

When designing your stable, the size and placement of windows will take some consideration. Because windows are important for ventilation, you'll need to consider how you want to open the windows and what will be safe for the horse.

Safety

Horses and glass don't mix. Any window you install will need to be of a non-breaking material, covered with some sort of protective mesh or grill or placed higher than the horse's head. Placing windows above the horse's head defeats the purpose of the horse being able to see out and receiving maximum light. So, windows made of non-breakable material such as Lexan© are an option. For the average horse owner though, these might be cost-prohibitive.

The most common option is glass protected with a grill or grate. These can be custom made, or they can be bought as pre-matched units. The grill prevents the horse from pushing against the glass, and if the windows can be opened wide, prevent the horse from trying to escape through the opening.

Spacing between the grills should be a minimum of three inches (7.6cm) apart. Some people use mesh to cover windows. However, the downside of mesh, like hardware cloth, is that it bends, and the glass behind it can be broken.

If the window swings open, rather than slides, it will need to swing out of the stall. This can make placement for opening windows tricky if there is a pasture or paddock outside the window will swing into. If this is the case, you may need to install sliding windows with a grill on each side.

Ease of Use and Upkeep

Your horse won't be the only one that will enjoy the benefits of a bright barn. You'll want to install windows that are pleasant for you to use and clean. The rails of sliding windows tend to fill with dust and chaff over time and require frequent cleaning to keep them easy-sliding. If the wood-frame warps, as can happen over time, or even when weather turns damp, the rails can become distorted, and the windows will be difficult to open and close.

Mullioned windows look nice, but just like the ones in your house, are hard to clean. You probably won't want to do much more than give your stable windows a quick cleaning every so often, so choose a design that will be easy to mop down without a lot of finicky details to pick dirt out of.

Windows With No Glass

Dutch doors and shuttered glassless openings are alternatives to windows. Shuttered openings can be opened during good weather, but closed tight against storms and cold. The downside is that once the shutter or door is closed, no natural light can get in. However, if your horses are only stabled at night, or very rarely during the worst weather, this may be an option. Remember though that without glass, the ventilation will be very good, but the winter winds can go racing through your stable too. But in some climates, this option may be adequate and cost effective.