JG1982 That is interesting. We just finished a parking lot job almost 4 times (about 80 acres) the size of job you are talking about and the Terramodel file fully loaded with multiple surfaces was only 17MB. After we exported it for our client in Business Center is was only 5MB. The only time we ever see things get a little bogged down in Terramodel is when we are doing large heavy highway jobs or if we import a file that has a lot of block elements. But the block element issue is easily resolved.