@kellyus1985 Yes, because one side of the lounge you want to place is 55 squares long, so it wouldn't fit.
If you don't have any placeable grids larger than 50x50, you'll need to bulldoze an existing lot. Or, if you'd prefer, you can build or refurbish a different gathering spot that fits into a smaller footprint. You could check the exchange for player-built lots as well. But be careful—some of them come with hidden custom content that can infect and corrupt your game. If you're not familiar with the process of cleaning a download, it's probably best to stick with your own lots.
When you want to convert a different type of community lot into a vampire hangout, it's easy. Just go to Edit Town, click on the map tag, and select the option you want from the dropdown menu.