An ātea, or town square, which is also part of the project, has been created in a space created by demolishing the old library and post office, and provides a link between Te Hononga and the main street.
A dawn ceremony and karakia will begin at 5.30am on Friday, followed by breakfast on the ātea and an official opening by the Prime Minister at 10.45am.
The building will open for public use at 1pm.
Project facilitator Lau'rell Pratt said everyone involved in the project was "really excited."
"There's been so many people working on it, they're all really keen to get into the building and experience it," she said.
Work on the ātea had been hampered by the July floods, so it was now a hive of activity as workers scrambled to get it ready on time.
Last week the carpark was being prepared for sealing, the ātea was being painted and decorated with mosaics, foundations were being prepared for the arrival of sculptural rocks, and finishing touches were being applied inside.
"There's a good vibe, everybody's just getting on with it. There's nothing like a deadline," Pratt said.
Everything would be ready by Friday except a ticketing hub on the ātea, promoting local attractions.
Local iwi Ngāti Hine is a partner in the project, which has been managed by district council-owned company Far North Holdings. Almost all aspects of the project, from design to building to rammed earth construction, have been carried out by Northland businesses.
The new library will include a children's area, an activity stage, a large porthole window seat, reading nooks, more computers and better Wi-Fi, and expanded book collections in te reo and English.
Lotteries and Foundation North also made significant grants to the project.