Reduced Storage

• The space under your lower deck can be a valuable storage area for everything from pool toys and filters to patio furniture. When you enclose the area around your lower deck, you lose access to that space. That means you need to find somewhere else to store your summer items all winter, and that could be difficult if you have a small home and no storage sheds.
  
  

More Difficult Access

• Closing in the area around your lower deck means it will be that much more difficult to access the space beneath your home. That reduced access can make home repairs and maintenance more difficult, since you may need to remove the lattice work or other materials covering up the space below your deck. That in turn can increase the amount of time it takes for even a simple home repair project.
  
  

Hidden Damage

• If you close in the space under your lower deck, you could miss early signs of wood rot and other damage that could threaten the structural integrity of that addition. Leaving the space under your deck open makes it easier to check the structure for problems and determine when the time has come to apply a new coat of deck sealant and protectant.
  
  

Weigh the Pros and Cons

• Enclosing your deck can have a number of advantages as well, from cleaner lines to a more uniform yard look. It is important to carefully weigh the pros and cons of closing in your deck, and to evaluate possibilities that help you deal with the potential pitfalls. You could, for instance, build a door into the enclosed space under your deck, allowing you to continue using that area for storage.