The application for land west of Pagham Road and south of Summer Lane included vehicular, pedestrian and cycling access via an existing public right of way.
Arun District Council officers said the plans didn't accord with policies.
There was insufficient information to 'adequately demonstrate the proposal would not have an unacceptable impact on the safety of local highways and public rights of way, or whether the residual cumulative impacts of the development on the road network would not be severe'.
There was also not enough information to 'demonstrate that there will be no adverse impact on Functionally Linked (habitat) Land for dark bellied brent geese (which are a qualifying species of the Pagham Harbour Special Protection Area) or that the proposed surface water drainage scheme will not adversely affect water quality within the same Special Protection Area'.
They said no details have been submitted to show how the site would be laid out or delivered.
One letter of support was received stating that this is a better idea than the approved scheme for 400 houses.
There was one objection from the Sussex Ornithological Society about a lack of mitigation in respect of the brent geese which forage the site.
To see the decision, go to the Arun planning portal and use the search reference P/51/22/PL.