Filling in old foundation pit

I own a building that used to have a second structure in the rear of the lot ( approx. 25X25). The building was removed and I have a huge pit where the structure once was. We originally thought a 2 level backyard was cool but now realize the area is always shaded and hard to use effectively. I would like to fill in the pit to raise the area to grade making the space more usable. The building is fully attached so it is not easy to have a truck unload dirt. Any materials will need to be brought through the first floor apt. Aside from filing with an architect, installing poles and building an elevated deck structure can anyone think of a less expensive method to fill this hole? I need to raise the area about 5 feet. Could I hire cheap labor to bring wheelbarrows of dirt through the house? Would this require a permit? thanks for any advice.