Scrap Buildings
From BotE Wiki
Existing buildings can be scrapped in the submenu Structures of the System Screen. This is useful if you have for example too much production plants and therefore the upgrade costs are unnecessary high.
A Leftclick marks a bulding for scrapping. Every additional Leftclick on this building increases the scrapcounter by one.
A Rightclick reduces the scrapcounter by one.
The building will be removed at the beginning of the next round.