"The Crown manager will focus on the urgent need for broad performance improvements and ensuring the council has adequate processes and capability in place. This will include overseeing the council's building control functions and ensuring that the council regains accreditation as a building consent authority,'' he said.
The manager would stay in place until December next year, allowing the council time to return to a "robust organisation that does not require this level of management again in the future''.
Mr Williamson said the council's ability to issue consents would not be affected.
"The council will lose its building consent accreditation from Monday, 8 July. This does not affect the ability of the council to issue consents. Ministry of Business, Innovation and Employment officials will continue providing support to the Council and will work with the Crown Manager.
He said staff at the council had been doing their best.
"There are good people working hard to issue building consents in a timely and efficient manner. These people need good systems, procedures and leadership to support them.
"The Crown manager will provide the necessary leadership to overhaul the Council's building consent functions and enable the council to regain its accreditation,'' he said.
Christchurch City Council chief executive Tony Marryatt has taken leave over the building consents debacle and the Government has launched an urgent inquiry to see if any buildings are dangerous and need to be demolished.
International Accreditation New Zealand, which withdrew the council's ability to issue consents, has raised concerns over technical processing that means building consents might not meet the requirements of the building code.