Earlier quoted context omitted.
Up until last summer (when the Government won a case letting them change the law), having your expensive house owned by an offshore corporation was the canonical way to avoid a particular type of UK tax called Stamp Duty. When you buy a property, you have to pay Stamp Duty [1] on the value it's sold at. Stamp Duty uses marginal tax brackets, and the highest one (for the portion of the transaction over £1.5M), is 12%.…
Even with the new taxes, people were/are still purchasing through foreign companies (that way, you avoid the 0.5% stamp duty when the shares are sold?). They do have to pay the Annual Tax on Enveloped Dwellings (ATED) then though, which is basically an annual tax that needs to be paid when a corporate entity (i.e not a person or a trust) owns a property.
On a (for example) £7M house you would have paid £750K Stamp Duty, or if sold though a corporate transfer, £35K of tax on the shares and £36K/yr ATED - so holding it for less than twenty years would have been a deal, assuming no other possible savings from the corporate option.