Residents also oppose the proposed block of eight two-bedroom flats and six one-bedroom flats on land adjacent to 4 South Road, because they say it will put a strain on the drainage system.
Many people in Lower Broadmoor Road, South Meadow and School Hill believe that if the application is given the go-ahead it will cause a landslide of building development in the area.
Daphne Sandiford, of Lower Broadmoor Road, said it wouldn't be long before Crowthorne was turned into a "concrete jungle".
She said: "If these flats go ahead it will be the start of an over-developed Crowthorne.
"I think the council is testing the waters to see what they can get away with.
"Before we know it there will be developments everywhere and the few green field sites we have left will disappear.
"The council is going to have a fight on its hands."
Philip Fowles, of South Meadows, said Crowthorne is a "rural oasis".
He said: "At the moment we have a lovely view from our house and the flats would be an eyesore. I work in London and I enjoy the quiet when I come home to Crowthorne.
"I don't want my peaceful home ruined by such an intrusive development.
"There are a number of other planning applications round here and I fear before long the area will lose its country feel."
Mr Fowles also highlighted the recent flooding and drainage problems he and his neighbours have experienced.
He said: "The drainage system is already on its last legs, it will only get worse if more flats are built."
Another resident of South Meadow, Alison Sands, helped collect a 101-signature petition which was handed into Bracknell Forest Borough Council offices on Monday.
She said: "I think it's disgusting. We don't need any more developments round here. I have children and I'm concerned about the extra traffic by the school as well.
Another resident of South Meadow who wished to remain anonymous said: "Many of the residents round here work at Broadmoor Hospital and work odd hours. We need to be able to sleep during the day and that privilege may well be lost."
If the scheme is approved it will mean the demolition of nine existing garages.
Crowthorne Parish Council has received several letters of objection but is recommending the application be approved.
Cllr Bob Wade of Crowthorne Parish Council said: "We appreciate the residents'
feelings but all the planning officer can do is look at the planning issues surrounding that particular application and not the consequences of future nearby developments."