oops. i was not yet finished with my post ...

it now should be possible to upon build/upgrade
# draw the ghost building if there are no permanent obstacles like stone/water/sand
# draw clearing until all cleared and guard area until hostile buildings cleared
# draw forbidden until freed
# start building

so if placed in the middle of some forest, the ghost building with clearing area waits until the area is cleared maybe forever, but you can plan your town into the woods, too.

we have to check how efficient a 1 wide clearing layer can prepare the upgrade of a pool in fertile lands. maybe it keeps switching between forbidden and clearing.

Why do you make the forbidden area?

I think clearing the area a new/upgraded building needs automaticly
before placing the construction site is good idea and should be doable.

Your second point sounds nice, but I think it would be complicated
to do it right.  I don't want to see 12 globs of mine bringing resources
to a pool upgrade construction side and then having an enemy player
micromanaging one of his globs there.
(Building a wall or just imprison it between forbidden areas.)
Resources also would be a problem, for almost the same reason.
You would always have to have a free glob around to cut it back.
(I'm glad if I have enough globs to carry the resources.)

Also it is quite natural that no nonconstruction workers cross
construction sites - and I have never seen wheat growing there in
real life.  So you can't call this part a bug.
But I would like the things you said for the game - I just don't
see how your second point could be implemented without causing
more harm than it would do good.

I would have prefered to discuss this on the glob2-ideas mailing list.  Before putting a good result into this wish list.

As it is very annoying and micromanagingish to have to first clear ressources around a building and then make the 1 wide area around this building forbidden (but leave 1 free so units from that building can leave it) to upgrade it i consider this to not be just a wish but a minor bug. These tasks should get initialized just by clicking upgrade.

Same with new buildings! New buildings are nothing but a plan to build something. They should neither block own units nor foreign units nore nature. but as soon as globs are free for the task they should care to clear the area and make it blocking not before the've put the first ressource in.

this bug goes loosely together with #15229