An international donor conference for Gaza reconstruction is to be hosted by Egypt on Sunday, with the participation of Norway and the Palestinians.

Mofeed M. Al Hassina, the Gaza-based minister of public works and housing in the Palestinian government, said that if the crossings into Gaza from Israel and Egypt were fully opened it would take five years to complete the reconstruction. But the way things look now, he said in a telephone interview, it could take 10 or 15 years.

So the arrival of the small trailer homes — provided by a British charity, Human Appeal International, in cooperation with Mr. Hassina’s ministry — was greeted here with mixed feelings.

Mr. Najjar and his wife, Salma, had been allocated caravan No. 13 in an encampment across the road from their former home, one of two such encampments in Khuzaa.

“We took it because there is no other place,” Mr. Najjar said.

Like many here he has been renting a small home in the meantime, but the $2,000 provided by the authorities for temporary rented accommodation will soon run out.

“I see moving here as very difficult,” Mr. Najjar said as he looked at the cramped interior of a trailer while waiting for a representative of the charity to deliver the keys. “It’s like moving from heaven to hell.”