I am looking to certify only part of a manufacturing building, which will be a newly built extension. In doing so, I'm wondering about where I should put my LEED boundary. Should it include any outside space, which is also used by the existing building?

I assume this will also affect my entrances, as the existing entrance to the manufacturing building (not part of the planned certificate) will probably be the main entrance to the new extension.

Any help gladly received.