As a rental? You mean you will be renting it out?
There's a whole huge thread covering this subject on here somewhere.
Basically if you remain resident in Canada you are subject to US income
taxes on the rental income, as well as Canadian income taxes (you claim a foreign tax credit for the US taxes).
Also it will be subject to the Canadian capital gains tax when you sell it.
Have a read of:
http://www.cra-arc.gc.ca/E/pub/tg/p151/README.html which explains the rental situation in more detail.
This is somewhat out of date now as under the new tax treaty it has to be treated as income effectively connected with a US trade or business, but any sensible person would have chosen that option in the past anyway to avoid the 1042 requirement and the 30% NRA tax.
Steve.