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Adding A Basement Underneath A Current House‏

Question: I live in Northern California, and I would like to add a full-sized basement below my house. At present, my house is an older Craftsman-style house from the 20s, with nothing more than a 2-3 feet crawlspace. Our house is incredibly tiny, and we need more space! I grew up in the Midwest, where we had basements, and I would like to have one now. To complicate matters even more, I would like the basement to be larger than the house itself, so that I could later expand the house and add an additional floor above the current one. Perhaps it would make more sense to just tear down the house and start from scratch, but the house has a lot of character. However, character or not, if it will be so outrageously complicated and/or expensive to add a basement below the existing house, I will probably go that route. What are all of your thoughts?

Answer: Basements were created in order to house the furnace and coal necessary to heat the home in colder climates. They were never considered to be "livable" space.

To add a basement under a currently built home is possible, it means jacking up the home and excavating underneath - an expensive project and subject to local ground conditions - it is generally less expensive to add a second story.

Building the basement bigger than the footprint of the current home adds the complexity of supporting the home using beams and then of course there is the problem of capping the area that is not covered by the home.

In the long run I think it would be less expensive to demolish the old home and start over.