As a person who is not intimately involved in the financial aspect of building homes, but is “in” the industry, I can tell you that there are many factors that make a home in San Diego/California more expensive than Texas.
Environmental fees were mentioned, that is true. Texas does not have as many environmental regulations as California. There are also many more fees and requirements imposed by local agencies, cities, and county gov’ts. There is also fees for checking the plans, and fees for making sure certain things are built. For example, sometimes the agencies and gov’ts will require that you not only build sidewalks for the road leading up to your new homes, they will also require you to put in money in a fund for drainage.
Some people will interpret this post as a justification for the higher prices of today’s real estate. That is not necessarily true, but most people are not aware of the high costs of fees (i.e. taxes) that go into a house. From start to finish, it can take five years or more to build a house. The carrying costs for such an investment and doing that for five years is pretty high.