I am currently doing some thinking about building a new home and the thought of having multiple levels of concrete in the basement crossed my mind. What i was thinking is one step (6") down from the finished basement into the mechanical/plumbing room with sump pump (furnace , etc elevated) and the same idea in the laundry room with sump pump. Before i go any further i should say that i have never built a house and have little experience with or knowledge of concrete. The reason i thought this might be a good idea is that if my basement were to flood it could possibly be isolated and not ruin the finished living spaces. I know that there are things that can be done to help prevent flooding (dry location, weeping tile, damp-proofing walls, eavestrough, landscaping, etc.) but there is always the unexpected washing machine malfunction, or plumbing pipe leak, etc. I know i am probably paranoid about his but i would hate to see my finished basement flood. Is this an idea that would work? How difficult is this to construct? Please let me know your thoughts and your rational so that i can understand the potential issues. Thanks, NorthernOnt

The absolutely best way to prevent basement flooding is to not have a basement. Or call it a fully exposed basement or garage if that type of space is needed.

jonr- I agree completely. The only reason i am considering a basement is because i believe it is a relatively cheap way to double the square footage of a bungalow...when compared to doubling the footprint or another story. but i could be wrong.....

That's the important question. But be sure to compare a frost protected shallow foundation + extra story to a basement with the same level of heat loss, windows, drywall, etc. Digging, concrete, waterproofing, drains, conduit, etc aren't cheap.

Thanks. I will have to look into the pricing in more detail.

Rather than going with the "multiple levels", just put a sump in your basement and make sure it is well served with a pump and a backup.

If you have a walkout basement like I do, just put a floor drain in every basement room that has a water supply. If not a walkout, you can still put the floor drains in, but just route them to a sump pump.

I used a 550 gal concrete septic tank for a sump. Just dropped it in about 6 feet below basement grade with a riser and an access hatch.. Low footing drains and all the floor drains go there. Gives you a little breathing room before the water starts to rise. :-)

A depressed sump area is a good idea. It's oftendone in commercial work. ICF Hybrid has a good approach. I have a client who used a 5-ft diameter X 5 ft pipe with concrete on the bottom and a lid. No step-downs and 100% usable floor space. In this particular case, there is an enclosed collection bin, with the pump in it. The rest of the space is for access and overflow.