The cost of land is too expensive in California. So if you buy a house that needs to be rebuilt, why tear down a 2-bedroom house and build another when you can

The cost of land is too expensive in California. So if you buy a house that needs to be rebuilt, why tear down a 2-bedroom house and build another when you can build a 4-bedroom for 20% more? My house was built in 1951. It was 2-bedroom and around 1000 sq-ft. A bedroom was added around 2000. We moved in 2013 and added another bedroom in 2017. So we now have a house double the size it was 20 years ago. In the process, a starter home was taken out of the market. Why didn’t we just move to larger home? Unfortunately, buying a new home would cause property taxes to reset much higher. Buying something 25% more than my home is worth now would cause property taxes to double.