Christchurch’s Catholic Diocese has unveiled plans for a new $80 million Cathedral of the Blessed Sacrament.

The 800 seat Cathedral will be built on Barbadoes Street, returning it to the traditional home of the Diocese following the Canterbury earthquakes.

The project will also include a Perpetual Adoration chapel, a community centre capable of holding 300 people, landscaping and parking.

Bishop Michael Gielen officially launched the campaign in a pastoral letter read at Masses across the Diocese.

He said the new Cathedral would serve as a beacon of faith and respond to the realities of the present day.

The design has been developed in partnership with Christchurch architecture firm Warren and Mahoney.

Cathedral campaign leader Tony Brazier said the $80 million budget reflected a focus on financial responsibility, sustainable construction, beauty and dignity.

About $45 million is expected to come from insurance proceeds and the sale of diocesan assets.

A further $35 million must be raised, with more than $19 million already secured, leaving about $16 million outstanding.

The Diocese said it would move towards final preparations for construction once another $8 million had been raised.

Bishop Gielen and many priests across the Diocese have committed to making weekly financial contributions for the next five years.

No construction date has yet been announced.