I built a house recently and wanted to add mesh roofing to it, the house is 99 prims and the sections of mesh I want to add are 3x 14 prim, 1x 8 prim, and 2x 4 prim sections. When I added the mesh onto the roof and linked them all to the building it lowered my building's total prim cound down to 85? How does that work and is it really only 85 prims now??