The duration you need to live in a house to avoid paying capital gains tax on its sale depends on your country’s tax laws. In many places, such as the United States, if you’ve lived in the house as your primary residence for at least two out of the five years preceding the sale, you can exclude up to $250,000 of capital gains from taxation if you’re single, or up to $500,000 if you’re married filing jointly.
However, tax laws can change, and different countries have different regulations regarding capital gains taxes on property sales, so it’s essential to consult a tax professional or government resources specific to your location for the most accurate and up-to-date information.