Between five and seven million people had to leave their homes as a result of fighting.
Many people had their homes destroyed - either in the US bombing, or during fighting before that.
Many families now share with friends or relatives - or live in refugee camps across the country.
The new government will use the £2.5bn promised by countries around the world to rebuild houses.
They also need to improve:
- sanitation and sewerage works
- health services
- telephones systems