The retrofiting of the shelter is aimed at providing temporary shelter until more permanent housing arrives.
The federal government has purchased 22 new modular houses, with the hope that they'll be in place later this winter.
Aboriginal affairs minister John Duncan says families in the northern Ontario community now have access to "safe, warm, dry shelter."
The Attawapiskat First Nation declared an emergency in October because 25 families were living in housing too flimsy to face the harsh winter.
In response, the Red Cross raised $300,000 from Canadian donors and flew in emergency supplies for families in the most precarious conditions.
Meanwhile, Ottawa has placed the band's finances in the hands of a third-party manager, accusing leaders of mismanaging federal money.
The decision has infuriated band leaders and sparked a legal fight.