Are slab on grade foundations cheaper than a basement?
My question is, when taking square footage into account, is it cheaper to build a basement for my new home or would it be cheaper to build a slab on grade and add an extra room - also, which is going to be more efficient to heat and keep cool? I'm near Portland Oregon - thanks!
If the history of our website is an indicator, this question will for sure invite a heated discussion, but we welcome that : ) We’d choose a slab on grade over a basement almost every time, and in most cases yes, a slab is cheaper in our experience. But that is partly due to the way we build, where we’ve built, and variables that many builders don’t consider (durability, air quality, maintenance, etc).
Building basements properly is more expensive than the way most basements are built (ie: doomed to fail) so the problem off the bat is that most basement advocates are building wrong, and therefore comparing apples to oranges. But we have a page on that very dilemma, have a look here first:
Slab on Grade or Foundation and Basement; Which is Best?
There are some cases when a basement makes more sense, like urban infill lots with height restrictions, but even then we’d go with an ICF hybrid to avoid some hidden costs, see our page about raft slabs for poor soil quality here. But where near Portland, is it urban or country? What type of soil, and how much space do you have? That’s key to finding the cheapest foundation method.