"It seems that your cat is definitely unhappy with the new bathroom setup.
Most feline behaviorists suggest having one more litter box than the number of cats you have, without exceeding a total of seven litter boxes. Therefore, if you have one cat, you should provide two litter boxes. The rationale behind this is that, similar to their wild relatives (like lions and tigers), many domestic cats prefer not to urinate and defecate in the same location. They often appreciate having their own designated bathrooms. Thus, adding an additional litter box should be your first step. Since we know that your cat's issue was likely triggered by your renovations, it would be ideal to keep a litter box in its original location and add another box where you relocated it during construction. Be sure to show your cat where both boxes are located.
If this initial step does not resolve the issue, consider the following additional measures:
Change the litter substrate to a different type, or revert to the previous one if you recently changed it. Relocate the boxes away from any noisy appliances. If the boxes have hoods or covers, remove them to allow for better air circulation. Ensure that you scoop each box at least once daily. Verify that the boxes are appropriately sized; they should be at least 1.5 times the length of your cat. Thoroughly clean all areas where the cat has soiled using an enzymatic cleaner to eliminate any lingering odors, which will help prevent the cat from soiling the same area again. I recommend using a product called Nature's Miracle, available at well-stocked pet stores"
Cat Vet: Dr. K