Design A Basement

Why are most new houses in the Seattle area built w/out basements?

In British Columbia (same geography & climate) where I live new houses have basements. They even blasted bedrock to put mine in. In Seattle there are many neighborhoods with so-called McMansions (Buchan, etc.) but none of them have basements. Isn't this weird? Wouldn't that space be useful? I find this especially bizarre in new homes and townhomes where basement space would make an essentially cramped space more livable (room for a family room, guest bedroom, etc.) Any ideas?

Public Comments

1. to save the builder money and create more profit for them when they sell the house
2. because they are way to lazy to put them there
3. Partly cost and partly to do with the International Building code. See Chapter 5 of http://www.seattle.gov/DPD/static/3chp567_LatestReleased_DPD_001934.pdf