The sharp investors (domestic and foreign) already have lots of ways around the tax laws.  Nominee buyers act as fronts for foreign buyers.  Layered Numbered companies and Trusts buy tons of real estate and then the companies trade hands off shore and the "ownership" of the houses never does (thus off-shore buyers taxes. capital gains and land transfer costs are avoided).  

Strict application of existing strict Anti-Money Laundering rules to determine exactly who the BENEFICIAL owners of the property being purchased at all times.  Failure to adhere to the rules or aid and abet evasion should result in swift and very public $$$ fines and jail times for lawyers and real estate Agents involved.    A flat 15% of all property sales should be held back until the seller proves that (a) the property was LEGALLY and actually their primary residence or (b) Capital Gains tax is paid in full.   Failure of the lawfirm representing the seller to withhold would result in heavy fines and jail time.