A new-look Cathedral Square would hold 10,000 people and feature a special space for the city's youth.

Regenerate Christchurch has unveiled the design, which is now out for public consultation.

The area, bordered by Kilmore Street, Manchester Street, Hereford Street and Cambridge Terrace, would be big enough to hold events and concerts.

Urban designer James Lunday said a youth-focused area would be outside the central library.

He said a ‘cathedral gardens’ would reintroduce native vegetation into the city.

"When you go in here, you want be in Chicago, you won't be in Paris, you won't be in Auckland. The landscape will tell you that you're here in New Zealand, in Canterbury, in Christchurch."

Mr Lunday said it's vital to get on with the project, to make the city more attractive for businesses, visitors and locals.

"The clock is ticking and I don't know anymore than you do but can you imagine leaving the rest of the area in the condition it's in when you've got all these public buildings opening."

The plans are out for public consultation till August 21.

The library plaza design (Supplied).

Cathedral lawn plaza design (Supplied).