The building is shared by three Christian sects - Catholics, Greek Orthodox and Armenians - who have traditionally viewed each other with suspicion and are wary of upsetting the brittle status quo that governs the site.
Some measure of the complications involved in a renovation of this type can be found in the Nativity's similarly ancient and fractious sister church, the Holy Sepulchre in Jerusalem. When a 1927 earthquake badly damaged that building, it took the rival sects more than three decades to agree to major repairs and another three to complete them.
Today, the increasingly dire state of the Nativity's roof and the intervention of an external player in the form of the Palestinian Authority - which has circumvented the old rivalries and allowed all to save face - has led the three churches to agree to a renovation to be arranged and funded by the Palestinian government and international donors.
The PA and its president, Mahmoud Abbas, are eager to win recognition for the basilica from Unesco as a World Heritage Site, but an earlier application was not accepted because Unesco did not consider the Palestinian government a state.
That changed last month, when, in a controversial decision that triggered a funding cut-off by the United States, the UN's cultural arm decided to grant recognition.
The Palestinians are now hoping their application will be approved. The renovation is motivated, in part, by a desire on their part to prove they are responsible stewards of sites of global importance.
"Our president has issued a decree to restore the roof and to prepare for the restoration of the church on behalf of the three churches and in coordination with the three churches, which obviously cannot do it on their own," said Khouloud Daibes, the Palestinian tourism minister.
A high-tech survey by experts from Canada, Italy and elsewhere ended earlier this year.
Palestinian officials hope the three churches will sign off on the plans and that the renovation itself will begin in 2012. It is expected to cost between US$10 and US$15 million (NZ$13m - $20m).
- AAP