The council rejected the proposed development on several grounds including safety as the carpark would gave been built close to a runway at the airport.
The RCSI applied to Fingal County Council in September to develop a six hectare site near to the airport at Swords for a surface carpark.
In its judgment Fingal Council rejected the carpark and said that it would lead to a significant increase in traffic on regional route R132, which could lead to traffic congestion.
The planning authority also said that it was not satisfied that the development could not happen without infringing on the safety zone around the airport runway and said it would increase risk should there be an aircraft incident.
It also said that given it would lead to a large increase in traffic on the area, an environment impact statement (EIS) would be required before it granted planning permission.
The RCSI had not submitted the EIS with its application.
The RCSI said that it had made no decision on whether to appeal the council’s judgement.
“We’re going to review the situation in light of the draft Fingal development plan and other plans for Dublin Airport,” a spokeswoman for the Royal College said yesterday.
She did not indicate if the RCSI was looking at any other sites in Dublin.
The college has used commercial ventures to fund its development and has recently launched a €60m expansion of its operations.
The rejection of the application comes as a surprise as two year’s ago permission for a private carpark run by the well-known developer Gerry Gannon was approved.
His plan had been objected to by Aer Rianta on safety grounds, but this was rejected by planners.