Thanks to digital photography, I can keep my models a lot longer and in zero space… Ordinarily, I tear them down (and strip them of useful parts and trash the hulks) after anywhere from a few months to a couple years, with a few exceptions, like dioramas that I’m particularly proud of, or kits that are no longer in production and with little chance of them being re-released (or only available unbuilt for ridicously high collector prices)…
After a while, I get sick of looking at 'em, the cats inevitably get up there and bite parts off or knock 'em off, and if I’d kept every kit I’ve built, I’d have needed a museum-size display area, lol… Heck, I reckon I’ve built about 1800 models altogether… And if I got another 20 good years, I got another 500-600 to go…[;)] Got over a hundred on-hand right now (not counting figure sets, and thanks to some really good-hearted folks here who helped me out after my place got robbed last year), lol…
So, I never have more than maybe 30-40 or so on the display shelves… But yeah, they’re just open shelves, mounted to the walls… I don’ like cabinets, since they have a big “foot-print”… They also limit the models to smaller wingspans, whereas shelves only need three points-of-contact for the gear… Wings and noses can handle over-hang…
Shelving, I can put that up anywhere, like over the couch & love seat, desk, whatever… A 10’ x 12" x 1/2" pine board, three shelf-mounts, 18 screws, 9 anchors, and I’m good to go for another 6-10 dioramas, depending on the base-size… i could display more models, but I only do dioramas, so I take up more room than most…
In the War Room, I have a 32-inch wide hollow door that I turned into a shelf/table… I use it for large dioramas, like the Monogram B-29/B-17/B-24 dios… It’ mounted to the wall, and has two legs in front to support the front… I use the area under it to store unbiult kits.