How can I gain more storage in a small house?

Go up on the walls. Use baskets and shelving for more storage

Could you use the basement if it were dry? If you don't want to pay a professional to waterproof your basement, you could still seal any cracks, run a dehumidifier and paint the interior walls and floor with a waterproof sealer. A dry basement would give you a lot more storage space.

when i moved to this 50's fixer, my basement would have 4 ft wide puddles after a rain. start with a dehumidifier and set it up so a hose takes the water to a drain.

find plastic storage containers the large size w/ lids for what you need to store in the basement. right be for the fall semester is a good time to get them- usually on sale then. you can also use cement block and board shelves. set the block on the narrow end and slip boards in the holes.

you may need to bank soil around the foundation....when i empty my potted annual flowers the dirt goes to the house's foundation.

Since I have limited floor space too, I go vertical for storage. Also, I turned my coat closet into a pantry by adding shelving. Hope that helps.

Bedroom create a platform bed with storage drawers or cabinets.

bed w/drawers... https://www.youtube.com/watch?v=mWZ5EdxQ8NY

bookcase bed... https://www.youtube.com/watch?v=nQdUPI-4WMY

cabinet bed.... https://www.youtube.com/watch?v=vai8xV6jD60

If you have an attic or garage, store your out of season, sports stuff etc there in rubbermaid tubs, mark everything so your not searching for the right tub.

Kitchen, hang a pot rack or put a grate on the wall to hang your pots. Create toe kick drawers under your cabinets for extra stuff.

Closet, put in a second rod for more hanging space.

Bathroom create recessed shelving between studs. Hang a shelf over the door to store your linens. https://www.youtube.com/watch?v=VmeLocJk8Ss

Honestly when I'm stumpted I search small (room name) storage ideas on Pinterest.

We had the same problem, so we bought a small 8ft x 8ft shed and built it in 4 weekends with some extra building during the weeks in between when necessary. If you do this, make sure that you hire a termite prevention specialist if you buy a wooden kit. we wish we had.

As suggested in another post, run a humidifier that you can attach to a hose and run it to a drain. I had to do this once and used a heavy wire to secure the end of the hose to the drain. Put up shelves or even the gray metal shelves. Use the vacuum bags to store out of season clothes as they will not be affected by the humidity. The same goes for extra bedding in the larger bags. You will be surprised by what you can store when you use those bags. If you have one of those seal a meal systems, you can store pictures if you cover them so that the pictures are not stuck to the bag, don't take out all the air out them so that the pictures don't stick to each other, you can stop the suction at any point and seal the bag. You just want them sealed in something water tight. Check on things you store in the basement occasionally to make sure they are fairing well, if you have to, bring a tote or two upstairs to air out once in a while. Make sure anything fabric is in something waterproof, just sitting in a tote they can still get a little damp and start smelling musty them they will mold or mildew. Been there, done that with books I thought were safe in a tote in the damp basement.