Two old Hercules Street cottages could soon be demolished to make way for the 23-metre-tall building, according to plans submitted to Wollongong City Council by Cowman Stoddart planners.

Designed by PRD Architects, the building would have 22 apartments over seven levels, with two basement levels of parking and storage.

The top four floors of the modern grey and white structure, which includes a single-apartment penthouse level, would be set well back from the street over a lower "podium" section, the plans reveal.

The building would have three one-bedroom, 12 two-bedroom and seven three-bedroom units, with a common room and kitchenette next to a ground floor outdoor area.

There would be parking for 27 cars and two motorbikes, as well as space for 12 bicycles in the storage area.

According to the planning documents, the apartment block would have "water sensitive urban design" thanks to a 16,000-litre tank in the basement.

The planners mentioned the NSW government's Illawarra Regional Strategy to justify the need for the building, which says there is a need to increase the supply of higher density accommodation in Wollongong.

"This proposal will provide high-density residential development within an existing city centre area that will enable better utilisation of available infrastructure, and provide additional residential accommodation opportunities," the documents say.

"[It] is considered suitable development given its type, scale, location and design."

Despite these assurances, members of the council's Neighbourhood Forum 5, which includes residents from Wollongong's central suburbs, voted earlier this month to object to the Hercules Street proposal as it was "totally at variance with the existing streetscape".

They said the building should be redesigned to be four storeys.

The proposal is on exhibition through the council's website until Friday.