The destruction of Gaza caused by seven weeks of war between Hamas and Israel is so severe that it will require 20 years of rebuilding efforts, according to an international organization that assesses post-conflict conditions. 

Shelter Cluster, a coalition of humanitarian organizations co-chaired by the Red Cross and the United Nations High Commissioner for Refugees, reported that 17,000 housing units were destroyed in addition to 5,000 units that had been damaged in prior military campaigns.

According to the assessment, the current condition is exacerbated by the already strained housing situation in the densely-populated Gaza Strip, where there is a 75,000 unit housing deficit because of the blockade that has severely restricted the entry of constructions materials since 2007.

Shelter Cluster said it estimated a 20-year time frame based on the capacity of the main Israel-Gaza cargo route to handle 100 trucks of construction materials each day. 

Earlier this month, Palestinian Deputy Prime Minister Mohammed Mustafa said that reconstruction would likely cost $6 billion or more and that he would push for a donors' conference to raise funds for the extensive undertaking. 

“Once a cease-fire is reached, we will have to tackle the immediate problem of rehousing those who lost their homes,” Mustafa told Reuters. “According to our estimates, they may number 400,000 people.”