Summary: If your lot is flat, and all other things are equal, it is generally less expensive (cheaper) to build above grade and to build with wood than it is to build below grade and to build with concrete or masonry.
Hello,
We are considering adding on to an existing house using a slab
foundation.
We live in MO and it is very rocky.
What I want to know is, would it be cheaper to have a basement with one story or have a slab and have two stories?
Thanks,
Renee
Hi Renee,
If your lot is flat, and all other things are equal, it is generally less expensive (cheaper) to build above grade and to build with wood than it is to build below grade and to build with concrete or masonry.
If your lot is sloped, a crawl space would be the next least expensive or you could even entertain digging into the slope to obtain a level area for a slab.
An alternative I have used is to level the actual building site (dig into the slope), build a retaining wall (with a drainage system), and build the house on a slab foundation on the resulting flat area.
The retaining wall could be made from wood, railroad ties, stone, block, brick, etc., or even an earth berm made from your own dirt.
There are always trade-offs in any construction decisions and with your project you can see you will have a few.
Good luck,
Carl
