Box up any valuable items in the basement to protect them. Use plastic bins if possible. Stack boxes on top of each other to make more room. Place the plastic pins at the bottom of the stack in case your dog decides to lift his leg and urinate on the box.
Cover electrical outlets, remove cables and cords that can be chewed, and get rid of any sharp objects that can cause an injury. If you don't have another place for these items, box them up or place them up high.
Move boxes and other items out of the way to create a nice space for your dogs. If possible, line the walls with your stuff so the dogs can roam through most of the space, or create a labyrinth with the boxes to give your dogs the illusion that there is more walking space then there actually is.
Select an area for sleeping and lounging. Choosing an area that's close to a window so the dogs can detect anyone coming near the home or up to the door is ideal. Cover the space with an area rug, then arrange doggy beds, old sheets and blankets in the sleeping area.
Set down newspaper or dog pads for accidents. Place the newspaper as far away from the sleeping area as possible.
Place bowls for water and food near the sleeping area, if you allow your dogs to graze. If you feed your dogs at specific times, skip this step.
Add some of your dogs' toys in the sleeping area. This will keep them entertained and make them more comfortable.
Add a heater or fan to help control the temperature if necessary. Put them in places where your dogs can't knock them down. You can also crack a window to allow fresh air to come into the space and dry up any humidity.