Think of like stock. You wouldn’t use your Facebook shares to for a new car or your monthly groceries, but you still have to report your investment gains on your . The same goes for a home you’ve sold at a .
When are sold, the income it generates can be offset against their cost but any or losses are capital gains, which is taxable. You do not have to the themselves, and if you bought but never sold any within the year, you would have no liability.