The (free market) economist would say it is efficient: the value of vacation housing exceeds the value of permanent residency.
If the concern is truly that the usage is overall extremely low (not just vacation vs resident), due to property value speculation...there is the idea that property taxes should be higher.[1] This will force productive use of the land.
However, raising property taxes tends to hurt residents more. So...it depends what objective you actually want to achieve.
If the concern is truly that the usage is overall extremely low (not just vacation vs resident), due to property value speculation...there is the idea that property taxes should be higher.[1] This will force productive use of the land.
However, raising property taxes tends to hurt residents more. So...it depends what objective you actually want to achieve.
[1] https://en.wikipedia.org/wiki/Georgism