copy items from one bld file to another

[digerati]

Ok so I am working on this house addition and I find myself make several backup up copies like addition-1.bld and addition-2.bld and so on. Some will have the existing home in them and then there are some where I delete a lot of stuff and all you see is the addition.

How can I copy objects from one bld file to another?

I sometimes make nice adjustments to one file and want to have those on the other files and  do not really want to recreate them.

[Doug.S]

I don't think it can be done for walls, windows (construction)

except to group and export a 3ds object....and then import....but the results are not very usable

I think it has been suggested as a future version capability