Gridlines

Im drawing up an existing building, and putting an extension on. What is the best way to place gridlines? Would 2 gridlines for the existing building suffice, and then just GLs for the new part? GLs are normally through structural elements-what if there are various wall types, eg stud frame, blockwork etc? Is there a standard that should always be used?

Lastly-for the gridlines relating to the existing building-would these still be placed as centre of structure? (will this be easily identified on site?)

Any advice/opinions most appreciated!

I'm assuming you have no as-built documentation whatsoever, therefore you literally are providing existing grids arbitrarily. If this is true, and you cannot find any document that maps out the existing structural grid lines, then I would still create gridlines at every major structural column intersection. I would use a convention of an X in front of the grid sequence, so XA, XB, XC and X1, X2, X3 and so forth. X would represent existing.

If you'd rather not show the grid bubble, you can edit this in the Grid Type Properties, where you'll see the gridline but no grid bubble to not confuse or complicate things. But since it's an existing condition, use whatever you feel is necessary. If you do in fact have some type of as-built in paper or PDF form, then obviously use their existing grid layout instead.

Hope this helps.

-TZ