Donald Trump has made headlines for proposing a rather ambitious “real estate deal” – buying the island territory of Greenland from Denmark. Danish Prime Minister Mette Frederiksen has refused his offer, but for anyone in the market for an island, let’s explore from a Scottish property law perspective how to purchase an island in Scotland.

It is not unheard of for private Scottish islands to be advertised for sale. Indeed, at present the “exclusive island estate” of Inchmarnock is available to purchase for offers over £1,4m. To obtain ownership over this, a buyer would simply need to follow the normal process for buying land in Scotland: entering into a contract with the sellers, paying the purchase price, and registering the disposition in his favour in the Land Register. Living on and off the land would be subject to the usual challenges of getting there, building anew or converting existing buildings, obtaining or growing supplies and restrictions on use if it is a haven for wildlife.

However, what about say, buying the Isle of Lewis (the birthplace of Mr Trump’s mother)? This would be complicated by the fact that the land in Lewis is owned by a variety of proprietors and as such it could not be bought in a single transaction. Even if a buyer successfully bought the land owned by all individuals and communities on the Isle of Lewis, they would still not own the whole island. The foreshore (i.e. the part of the sea that is covered at high tide and uncovered at low tide) belongs to the Crown, so the buyer would have to persuade the Queen (or rather the Crown Estate Scotland) to transfer ownership of that. Assuming that the buyer makes acceptable offers, all purchase contracts are adhered to and their title registered, the buyer would be able to own all of the land in Lewis. However, they would only be the owner in a private law sense, and as such the Isle of Lewis would still be part of Scotland. This would mean that Scots law would dictate what the buyer could and could not do with their land.

If a state wanted to buy the Isle of Lewis and co-opt it as a territory of that country (say the United States), the position would be even more complicated. This would be a matter of public international law rather than a matter of Scots property law. The basic concept is that the United Kingdom would be able to transfer the territory of the Isle of Lewis to another nation, provided that both states agreed to the transfer, as an international ‘trade’ deal of sorts.

However, thorny issues such as who would actually be able to consent to such a transfer under UK law and the people of Lewis’ right to self-determination would almost certainly arise if there was an attempt to transfer the Isle of Lewis to another country. Consequently, attempting to buy anything other than a wholly owned private island in Scotland would certainly be a “real estate deal” like no other.