Just a note for people who have problems with the hard badge - start a new town at easy difficulty level and secure the whole town. Then fix the helicopter and teach five people all skills up to 10. You can send them to a new town preserving their skills. That means you have five guys who can clear most of the squares on their own and wall them in just 2 days, not mentioning the scavenging bonuses etc.
Rebuild 1 was much harder though.
 "Rebuild 2"){kind=icon}
 "Rebuild"){kind=icon}
 "Take Something Literally"){kind=icon}
 "Starcom"){kind=icon}