Unable to replace grass with stone

@PugLove888   That is definitely good news! I remember using the Terrain Tools in Sims 2 (and possibly Sims 1). Sims 3 never stuck with me so I didn't get as far as working on terrain. Ya, the rooms thing when all things must match per foundation or wall height is probably no fun for some folks who download some of the greenhouses I made. Some are a building that would have to be placed before your home or it will place instead of your existing building, I assume. That's how I place them when using them with a new house build when I use them. Otherwise you just need the greenhouse or plant rooms. I have gone so far as to, when I wasn't positive I had enough yard or building room space to place a room without destroying anything, to go 2 layers down (two basement levels, since I occasionally have issues when only going one level down for this, and making a room there bigger than the room I'm placing and with extra tall walls if there are trees in the room (greenhouses) then placing the new room there and bringing the items up one at a time to the yard or home area that I want them. Gotta do what works, and be creative often, with sims. 

Anyway, the Terrain Tools will be very helpful for your situation @Nimbindi , once they come out. I suppose, as @PugLove888 said, you can just do something temporarily until then. They should provide you a lot more versatility if they are like the old ones and allow you to raise and lower terrain to fit your needs, for example. So, @PugLove888 - do you just need to raise the ground where the room or item will be placed/built to the height that would match the house (in other words raise the ground the amount of height the foundation has added to the home) then the foundation will not automatically be added to the 'room', gazebo, greenhouse, etc., that you are placing in the yard? Do you happen to know if there's a video or information about this upcoming release that we could also view?