One of the things to decide upon when building a chicken coop is the general style and that can include whether or not to have the chicken house elevated. Normally the extra height is not too much – perhaps one to three feet. Here are a few reasons you might want to raise your hen house.
1. Protection from predators
Raising your coop even just one foot from the ground should help make it harder for things like rats to burrow or eat their way into the coop through the floor. If there is a nestbox overhanging make sure the floor cannot be pushed up from underneath as that could be a weakness a fox or some other predator may try to exploit (any catches should also be secured so they cannot be easily unhooked).
2. Easier Access
With small chicken coops especially, raising the house off the ground can make it easier to clean out than one that you have to stoop down to (or even worse, crawl around in!).
3. Shelter
A raised coop can provide additional shelter from the elements for your chickens. Having at least one or two of the sides solid (as opposed to just wire) will help to give more protection from the wind and rain (although try to position your coop somewhere fairly sheltered from the worst of the weather in the first place).
4. Dust bath
What starts out as a sheltered area for your chickens may eventually turn into a dusting area (as happened with my smallest coop a few years ago!)
5. Snow and Ice
There is less chance of your chickens getting snowed in if their coop is raised of the floor as the door will usually be well above the height of any settled snow. Watch out for slippery ramps though!
6. Extra Space
A raised house can give extra run space underneath and can make a big difference to the overall square footage they have access to. Even if they are intended to be free ranged there are sometimes reasons to keep your chickens in a secure pen area (such as because of extreme weather conditions or perhaps you are going out for the night and won’t be able to lock them in until some time after they have gone to bed etc.) and so the space under the house can be handy for that as well.
7. Floods and rotting
A raised wooden coop will help prevent the underneath rotting as quickly because it will not be in direct contact with damp earth and puddles (the wood would also benefit from being treated).
Thanks for answering that question so well! We are building a bigger coop this month, and were wondering why people build them off of the ground!