Canada and the US differ on Capital Gains on personal residences, but it may be possible that you get hit with Capital Gains taxes on the US side or on a vacation property. Something you can do to address this Capital Gain would be to increase your basis by any improvements you made on the property.
The IRS gives a pretty good description of what can be included in increasing your cost basis for the property, I don't think we will amend the US tax return, this is just to give you an idea of things to think about for improvements.
ImprovementsImprovements add to the value of your home, prolong its useful life, or adapt it to new uses. You add the cost of additions and improvements to the basis of your property.
The following chart lists some examples of improvements.
Examples of Improvements That Increase Basis
Lawn & Grounds
Central air conditioning
Air/water filtration systems
Lawn sprinkler system
Pipes and duct work
Soft water system
Repairs done as part of larger project.
You can include repair-type work if it is done as part of an extensive remodeling or restoration job. For example, replacing broken windowpanes is a repair, but replacing the same window as part of a project of replacing all the windows in your home counts as an improvement.
Examples of improvements you CAN’T include in your basis.
You can’t include: