Wendersnaven.com (a resource for nwn2 builders)

Converting placeables to environmental objects reduces the size of areas. I think it also increases performance for players. Environmental objects do not cut into the walkmesh, meaning that players will be able to walk right through them. Sometimes this is not an issue, such as when they are out of the walkmesh anyway, but otherwise you will want to use the walkmesh cutter trigger to keep players from walking through your objects.