A public meeting is being held to discuss Denbighshire council's plans to triple the size of a village.
Under its local development plan, the council claims up to 2,000 extra homes could be built at Bodelwyddan.
A consultation begins next week and if approved, the plans could see a new primary school, care home and new access from the A55.
However, the Bodelwyddan Development Action Group said the plans were "unsound" and "unsustainable".
The group was formed by resident Alice Jones, who said local people had not been given any information about the plans.
Denbighshire council said it planned to launch a public consultation next week at Bodelwyddan Community Centre between 1400 BST and 2000 BST.
Ms Jones said: "The proposals include building 1,715 new houses.
"We have a population of about 1,000 at the moment, and that would be expected to rise to about 6,000 over the next 12 years."
According to the 2001 Census, Bodelwyddan had 895 homes.
Ms Jones said the proposals would also include a business park, service area and filling station with an overnight lorry park, as well as other businesses.
She added: "Bodelwyddan is opposed to this development, and the people have sent a very clear message that these proposals are unsound, unsustainable, and the plans should be shared throughout Denbighshire.
"Development should be done, but on a much smaller scale, in smaller stages so that people can integrate into communities.
"You cannot just do a huge development like that and throw people together and expect it to work.
"It would take many years, and during those years there would be all sorts of anti-social behavioural problems."
The group will hold a public meeting on Monday at Bodelwyddan Village Hall at 1930.
A second meeting will be held on 19 October.