Rooftop gardens featured in all three designs, which were prepared by Jasmax.
The standalone library at Willow St was designed as a four-storey building with 4500sq m of usable floor space built around a deep atrium with a cafe on the ground floor.
An integrated museum and library were drawn with five storeys - the library spreading from the ground floor to the third, sitting alongside museum spaces on the first, second and third floors. The fourth floor had space for special exhibitions.
The Cliff Rd museum design was a single storey, with wings either side of the central entrance - one for the museum with exhibition spaces and the other for a wharenui, which had its own entrance, and an open outdoor space, or atea.
Councillors were shown the designs at a workshop on Tuesday, the first of three open workshops on new facilities this month. They were also scheduled to hold a fourth workshop - closed to the public - on November 30.
At their next committee meeting on December 5, they will make a recommendation to take to the full council on December 19.
A veteran of the council's 2007-08 failed museum attempt - where a waterfront museum was designed and costed only to be canned after an election shuffle - Baldock was determined not to see this project go the same way.
"We will get it done this time."
Engagement hub opening hours
Wednesday, November 8: 10am-6pm
Saturday, November11: 10am-4pm
Wednesday, November 15: 10am-6pm
Wednesday, November 22: 10am-6pm
Wednesday, November 29: 10am-6pm
Saturday, December 2: 10am-4pm