Monaghan County Council has refused planning permission for a development that would have seen the construction of 18 homes in Carrickmacross.
The application sought a change of use of an existing four storey office building at Derryolam Glebe House on the Shercock Road to allow for the construction of four apartments.
Permission was also sought for 14 two-storey houses, of between two and four bed.
However, the local authority said the application would be "contrary to the proper planning and sustainable development of the area".
It added that the applicant "failed to demonstrate that the proposal will not exacerbate flooding" or "result in residual risks to the area that cannot be managed to an acceptable level".