This is extremely optimistic. It's usually more like if you are going to stay in a place for 3-5 years then maybe it's worth buying. The first few years you are paying almost all interest and not much principle. In addition you need to factor in transaction costs (realtor fees, lending fees, etc.). Plus it can often take close to a year to go through the full cycle of buying and then selling a home. Using your one year rule just isn't realistic.