Adding Storage Under a Bathroom Sink

Under a bathroom sink is the worst kind of wasted space: visible, awkward, and usually just a tangle of pipes and cleaning bottles. The area below your vanity holds enormous potential, but most people leave it empty or stuff it haphazardly. A proper storage solution—whether a simple pull-out drawer, a tiered shelf, or a custom cabinet organizer—turns that chaos into usable real estate. Done right, you'll have fast access to everyday items and a cleaner-looking cabinet.

1. Measure the space and clear it completely. Empty everything from under the sink. Pull out any existing shelving or risers. Measure the width, depth, and height of the cabinet opening, accounting for the P-trap and supply lines. Note where pipes run so you know what spaces are truly usable. Take a photo of the pipe layout for reference.
2. Choose your storage style based on clearance. Decide between three options: a sliding drawer (works best if pipes are to one side), a tiered shelf system (good for split plumbing), or an over-the-door organizer (keeps items off the cabinet floor entirely). Pull-out drawers need 8+ inches of clearance; tiered shelves work in tighter spaces. If pipes dominate the center, an organizer on the inside of the cabinet door might be your best bet.
3. Install a pull-out drawer or shelf riser. If you've chosen a pull-out unit, measure and mark mounting points on the cabinet sides using the hardware template provided. Drill pilot holes, then screw the mounting brackets flush to the inside walls. Slide the drawer or tray into place and secure the front lip. Check that it slides smoothly without rubbing pipes. If installing a shelf riser, place rubber feet on the cabinet floor first to protect the finish, then position the riser and level it with shims if needed.
4. Organize items by category and frequency. Place items you use daily (toothbrushes, deodorant, hair products) in the most accessible spot. Group cleaning supplies together in a caddy or small bin. Store spare toilet paper, paper towels, or extra toiletries in the back. Use small boxes or drawer dividers to keep items from sliding around. Keep the area under the sink drain as clear as possible for leak visibility.
5. Install an over-the-door organizer if needed. If your under-sink space is too cramped for a drawer, mount a slim over-the-door organizer on the inside of the cabinet door. Mark mounting holes on the door, drill pilot holes, and screw the organizer brackets firmly into place. Fill pockets with small bottles and supplies. Make sure the organizer doesn't interfere with closing the door or hitting the pipes when you open it.
6. Test for leaks and make final adjustments. Run water in the sink and watch for drips for a full minute. Check that nothing has shifted or gotten pinched. Make sure drawers slide freely and all items are stable. If the drawer catches on pipes when opening, remove it and adjust the mounting brackets forward by half an inch. Confirm the cabinet door closes without resistance.
7. Add labeling and a moisture control solution. Label bins or drawers so household members know where things go. Place a small absorbent mat or activated charcoal under the sink to catch minor leaks and reduce moisture. If your bathroom has high humidity, consider adding a small wire shelf above the P-trap to improve airflow. Wipe out the cabinet monthly to prevent water pooling.