More than 20 objections have been submitted to plans for Kepwick House, part of The Sands development, offering a parking space per apartment and "magnificent" sea views.
Damon and Julia Robertson, who bought five holiday lets and a holiday home at The Sands in 2008, said developers had already shoehorned nine apartments into the base of Kepwick House and adjacent Lockton House "making the space feel overdeveloped".
Mr Robertson said the development as a whole had failed to live up to the original glossy promises. He is urging councillors to pay a site visit, saying: “If you study the plans you’ll see the new parking is off the ramp, has no pedestrian walkway and is surely not viable for health and safety.
“This is just more misery for residents, tourists and local people, who’ll have to put up with the noise and dust of construction for over a year.”
In comments posted on Scarborough Council's planning portal, another objector said the congested parking and "inadequate" spaces already caused complaints from visitors on customer review sites, adding: "It would be unwise to deliberately exacerbate this problem, especially for apartments that are marketed as five star quality."
Another who rents out her flat to holidaymakers fears people won't book if building work is going on, adding: "We are in a time where UK holidays have never been so important and 90 per cent of The Sands complex is connected to tourism. Scarborough has benefited enormously from this infusion of middle class tourists let's not ruin a good thing."
Planning permission was given on appeal in 2015 for three apartments on the roof, but not taken up. The latest proposals seek to build a mix of two and three-bedded apartments.
Development manager for Benchmark John Steven said they believed their proposals would improve the appearance of the building.
He said: “Sufficient additional parking provision is included within the scheme, and these will be EV charging spaces.
“The development is an improvement on the one previously supported by the Planning Inspector at appeal, because we are now able to take advantage of the whole roof, following structural surveys.”
The structures on the roof would be "floating" to prevent noise and construction "will only be conducted out of the peak holiday season".
There would be other measures to minimise disruption.