I am gathering info for a modern passive solar home on a terraced south facing lake lot.   The one terrace where most of my home would be has a rise of approx 20 feet.

I am planning 3 rectangular boxes set back on each other up the terrace to create deckspace for each level.  The boxes would be orientated so the long sides face lake/southern exp.  Maybe 50x30 for the largest box.  The walkout basement level would have 3 sides into the hill and lots of glass facing south/lake view.  2nd level would be partially in the hillside.

What is the general rule of thumb on construction on this type of lot? 

Is it cheaper to have more of the structure inground?  some sort of stepped foundation.(prob ICF.),  or minimize the walkout basement SqFootage? or build up the flat area w/ the excavation material to have more exposed construction to "raise up" the entire home?

In other words, will the cost of excavation, engineering and construction of larger, deeper basement outweigh the cost of minimizing the basement and adding more square footage above ground to the upper levels?

What basement height walls do I run into cost overrun as far as excavation, construction, engineering, chance of problems etc...I am planning lots of glass to the south/lakeview to get light in.  I could go as high as 10-16ft ceilings in the basement walkout level to scale up the 20ft height slope.

The other factor is I plan on putting in an inground pool in the near future in the lower flat, and does adding the excavated fill to build that area up complicate or rule out a future pool?  assuming you need good undisturbed base for inground pool.

Thanks for your info, this is a great instructional group of pros!

PS.  I met ICFConstruction at the site, he is a knowledgeable great guy.

I would think that with a 20' rise of slope, you would want the 2 lower levels to be backed into the slope. If you are using ICFs, this should be fairly easy to accomplish. Footer placement and interconnection between levels will be critical to stabilizing the project. If the top level is completely above grade, then the part that is not over the second should be placed on a crawlspace. Helpful hint for your knees: Keep the lower levels at reasonable 8-10' ceiling height. Especially if you anticipate moving between levels on a regular basis.

A basement with 10' to 16' ceilings will require more space for the stair run.  Also be aware that additional space may have to be used for a landing or two to break up the long run of steps.

Guys,
You should know we are in Minnesota, an area that requires a minimum of 42" frost protection. I think that is the biggest reason basement are so popular here is nearly half of the height of the basement would need to be built anyway. I think basements are overrated and see too many nearly flat lots made into a walk-out.

Slenzen,
Thanks for the complement. You have a very steep lot with an ideal south face, I think it would be great for two levels below grade, on the up-hill side, and you would need that 42" frost wall on the walk-out. You are likely limited to 3 levels by the city.

Yep, will be plenty of stairs & landings depending on level height, good exercise!  Planning on having this dandy of an elevator as well. 

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http://vacuumelevators.com/spanish/Elevator%20Operation%20Video%201.wmv


How about construction cost differences?  Is it less expensive to build more excavated sq footage below grade lower level(no windows/exterior finish on 3 sides)  as opposed to more sq ft in upper exposed construction w/ finished exterior/windows etc..? 

How about building up the lower terrace w/ the excavated fill a few feet.  Will that cause construction difficulty or complicate a future pool build?

I am following this with great interest  because we have the same conundrum.  We will build into a 20% slope of solid limestone so we definitely want to minimize excavation.  This will give us 10' ceilings in the walk out level.  We will have a walk out level, main floor and a small loft/library, so an elevator is definitely in our program, too.  My wife will have knee replacement surgery nest month.

Our excavated material (which cannot be used for structural fill by local code without a lot of testing) will go to create a pad for a patio.

The vacuum elevator is very cool, although it does not appear to be big enough for a wheelchair (one of our program requirements).  I will check their website for more info.

Bruce