Summer houses or second homes
Denmark has an opt-out (derogation) from the treaties.
Protocol 32 in the Lisbon Treaty permits Denmark to keep its national laws which prohibit foreigners from buying summerhouses and second homes in Denmark if they do not live in Denmark.
Denmark wanted to change its law on agricultural possessions law but was not permitted to do that by the EU Court.
When Austria, Sweden, and Finland joined the EU, they had a five-year transition period. Since 1 January 2000, the purchase of second homes has been permitted in these three countries.
Of the new member states, only Malta got a permanent opt-out from the free sale of houses. People have to reside in the country for 5 years to be allowed to buy a second home in Malta. All other new member states only got temporary opt-outs from sales of second homes and farms.