I own every in-game house and have spent and embarrassing amount of money on Crowns over the years to accomplish this. Decorating houses is my endgame and I know I am not alone in this endeavor. In the past the community has asked to up the limit for furnishings in houses and more recently the establishment of a Furnishing Bag with unlimited holding like the Crafting Bag.
While a Furnishing Bag is a wonderful solution to the issues housing enthusiasts face, it is rather inelegant and would not lead to more engagement in the game overall. So, my solution is introducing a series of storage facilities in game which we can earn though Quest Lines and not Crowns.
Ever notice how horribly organized warehouses are in ESO? Just crates and such strewn about willy-nilly. What if a new NPC appeared who was obsessed with organizing these horrible places? That NPC could then offer a series of quests to players which would allow them to unlock various "houses" which were storage themed. Could you imagine the hours of fun we could have organizing a Warehouse themed house! Then perhaps a Nursery for our plants and trees? Ooo, how about a subterranean cave space for all our mushrooms and bioluminescent plants? Hatcheries for fish and aquatic plants? It goes on and on!
I get it, most of us buy some of the larger houses to hold our furnishings, but the environments are cut up by buildings and terrain. How cool would just large log or stone structures with smooth stone floors be for storing items? Or a nice trim farm area or fields for plants and trees!
But again, I stress, these facilities should be unlockable through quests or perhaps harvesting goals to support the war effort, not Crowns. As housing investors, we have already spent enough and will continue to spend more in order to acquire our vast real estate portfolios!
Pretty, please with sugar on top. I mean you've already ruined my marriage due to my spending habits so it is the least you could do! (Ha ha ha, jk, my wife has been a pretty good sport about it)