Or at least pro-rate it.  

We could also make capital gains payable on all housing sales, but you get to claim it as a tax credit when you file your income tax. 

If you are a senior then you can claim the tax against tax paid in the past, and if your income is relatively low and you are working, then you can carry it forward.

That should take care of those who live here but do not file and pay tax on overseas income.