The art-deco brick wall that borders North Sydney Olympic Pool, with its arched bay windows and seashells moulded from stucco, is perhaps the most recognisable nod to the site's 1930s heritage.

Yet it's the fate of the complex's 20-year-old indoor pool building that has become a flashpoint for concerns parts of the site's history could be lost, as plans forge ahead for a major redevelopment.

The art deco brick wall at the pool, built in 1936, features scallop shells and parrots moulded from stucco.

North Sydney Council has submitted plans for the $57.9 million overhaul of the historic venue, including upgrades to the existing pools, a new "family leisure" pool and a replacement grandstand.

But prominent architects are protesting the removal of the building that houses the 25-metre pool built in 2000.