I've had an open pile for 14 years of just grass clippings. The occasional leaf or 2 in the fall if they land on my property. The pile is 4 x 10 and does not get much larger as I pull some really nice stuff out of the bottom. The height goes up in the spring and depending on the summer but never over 3 feet. The worms just love that heap. No smell, it just keeps working when it is established.
But alas, I have to get rid of my pile due to a neighbour's complaint. He said it has animals living in it and the city came to check it out. Turns out I can't have on open pile larger than 21.5 square feet in area and no higher than 39 inches. :dunno:
In all the years I've had the pile, never seen anything living in it except the worms. Guess it could happen if I was in a more rural area.
So I went on-line to check our local bylaws. Called up the bylaw guy and asked if I can build a composter around it with no size limitations so long as it is contained. He said he'd have to talk to his manager and would get back to me later.

raying:
He sent me an email saying my solution was acceptable. :thThumbsU
I am currently designing a 5 bin system 16 feet long, 3 to 4 feet wide and possibly 4 feet tall. Contained compost should not be any larger 4x4x4 feet as air can only travel a maximum of 24 inches into the compost.
And at this point I haven't decided to move it over about 5 feet or leave it where the pile is now. Although moving it would give me a really nice garden bed.
When I get it built, I'll post some pictures.
Cheers,
Javelin395