Help with stacking cage idea

I have six 8' x 30" cages. They each have 3 or 4 holes in them. The do not have pans. I have them sitting on sawhorses. All I have to do is rake underneath to clean up. I would like to build a shed to put the cages in so in the winter I can keep it just above freezing. I need to come up with an idea to do this so I don't have to buy new cages.
How would I stack them 3 high? i was thinking if I had shelves I could buy pans an elevate the cages a few inches above the pans. Anyone have any other suggestions?:?

If space is not an issue a very large shed could keep them setup the same way as you have them now, but heating would be an issue. I think stacking with removable trays would be the best option for space. You could compromise with partially sliding tray which drop the litter, but I feel you would be overly complicating the matter. Hard to explain building ideas in text, but a basic shelving system seems like a good place to start. P.S. Insulate and Ventilate.

Ever seen those cages with the slanted pans under them? Flush clean or something? Do something like that. Sorry I can't help with the name, but perhaps someone else knows it! I just know they have metal or plastic pans under the cages, but the pans slant back so all the poo/urine falls into a little catcher thing and then you can wash that down a drain. Something. Sorry! XD I've seen them in the ARBA magazine, I thought they were nice.

Cookie sheets or baking pans make great poop trays

One Flemish breeder I knew laid tarps over the tops of the lower cages (probably also over a board). But...she also cleaned every other day.

Some sort of shelf system should work. I imagine building sides about like a ladder to support the cages where you had the sawhorses before, with crossbraces to attach the ladder sides (and support the middles). Extra legs under the bottom wouldn't be a bad idea, either. Some sort of support along the back would be a good idea, also, depending on how sturdy your crossbrace supports are (I just have 2x2s on my age hutch crossbraces under the trays, so they sag a bit in the middle without support--the cages are supported by 2x4s, so they're ok).

Once you get the "top" cage hanging, and you get a bottom cage hanging under it, you can use soem roofing material like the link below, to make a tray that slants to the back of the cage so all the poo/pee slides down and onto the ground.
http://www.lowes.com/pd_77652-1115-1413C_4294806362+4294851230_4294937087_?productId=3043887&Ns=p_product_prd_lis_ord_nbr|0||p_product_qty_sales_dollar|1&pl=1&currentURL=%2Fpl_Tuftex_4294806362%2B4294851230_4294937087_%3FNs%3Dp_product_prd_lis_ord_nbr%7C0%7C%7Cp_product_qty_sales_dollar%7C1&facetInfo=Tuftex

Here is a thread I found that has a great picture. It's almost half way down the first page
http://www.homesteadingtoday.com/showthread.php?t=379038