Is a permit required?

I would like to build a storage loft in my walk-in closed. It has 13-1/2 ft. ceilings, so there is space to but in a second level about 8 ft. above the floor, and the upper ceiling also could be raised another foot, so that the loft would have about 6 ft. height. Since it's storage and not living space, do I need a permit? My building's manager asked for a drawing (before/after). Can you recommend someone who can do a drawing? Would like to do this by just using a contractor to build the new floor and raise the ceiling without time/costs of permits and architect. Thanks.