If you want to make your own underbed built cabinets is a doable DIY project and a very affordable one if you start with used furniture.
Step 1 - Find Old Furniture
Measure the width and length of your bed. You’ll want to purchase cabinets that will fit flush with the bed and that neither too tall nor unsturdy. Go to garage sales or look online for furniture that matches the length and desired width of the cabinets you want. You can purchase dresser drawers if you find they are easier to get hold of. They will just need more work than if you have previously used cabinets.
Step 2 - Fix Old Built Cabinets
Whether you purchase cabinets or dresser drawers, you should sand them down and stain them to match the headboard of your bed or other furniture in your bedroom. You can also replace the knobs if you don’t like the ones the cabinets or drawers currently have.
Step 3 - Turn Drawers into Built Cabinets (if necessary)
If you purchased dresser drawers, you’ll need to detach the front part of the dresser. Use a piece of plywood to build the top of the drawer into a cabinet. Use hinges and magnetic hardware to re-attach the front of the dresser drawer so that it opens like a cabinet. Likely, your cabinets or drawers will open from the top or bottom for the best results. This way, they’ll be shorter and able to hold the weight of the bed.
Step 4 - Assemble the Storage
Use wood screws to join the drawers or cabinets to one another. Make sure they are all flush. Use a piece of plywood that is the same size as your bed and attach it to the cabinets or drawers. You can use additional plywood to cover any extra space that is not taken up by the built cabinets. The plywood makes the storage space more secure when you put your box spring and mattress on top. It will better support the weight and you’ll be less likely to warp the wood.
Step 5 - Finish the Project
Once you’ve assembled the built cabinets, you can put the box spring and mattress on top of the whole storage area. Make sure that the cabinets open properly when the wait of the bed and box spring are on top. You can have someone lie in the bed to make sure it is sturdy enough for the weight. When you’ve determined that the storage built cabinets are sturdy and secure, you can begin putting your belongings in them.