The information that you've provided is way too vague to give any reasonable answers.

You are building a house and you're trying to decide between a finished walkout basement versus larger living spaces on the main floor?

Ask your contractor for cost comparisons for a basement vs. slab foundation, for starters.

Do you live in tornado or hurricane country?

Littlebug, thank you. No, we are not in tornado or hurricane zones.

The reason you do a walkout basement is because you have a "very sloped lot." The placement of the house footprint requires you to either:

A. Fill in the area over the deep slope up to the main floor level - but still requires foundation stem walls up to the 1st floor to hold in that fill.

B. Use the space that is naturally open below the first floor by excavating a part of that slope, and using the foundation stem walls as basement walls - requires an interior stair unless it is just used for outside storage.

B is much cheaper than A, and more useful. Realize that in areas of the country that has basements are deep frost depth areas. So if you have to dig down 48" anyway, you dig a little further and put in a basement for 'free' space. Your "sloped" lot is that but with no digging.

Can you post both designs?

WARNING: Posting your entire floor plan opens you up to facts you may not want to know, but should. Be prepared for suggestions that will make for a better design. Keep a thick skin, open mind, sense of humor, and a glass of wine within arms reach. You may not enjoy it, but everyone else will and you will be better off in the long run if you heed well the advice

The information that you've provided is way too vague to give any reasonable answers.

Agree. We're working with very little information here.

Contrary view- I am getting away from my sloped lot / walkout basement and moving to a single level with a great connection to the outdoors.

I feel the same way about sloped lots /walk-out basements. With this type of house, you don't have an outdoor connection in your main living spaces, and I would dislike that.

Mrs Pete exactly what information are you wanting to know?

Mark, i think a bottle of wine will be more appropriate. Thanks for the good info.

3onthetree very good info. All makes sense. we will stick to the walkout.

I’m team walkout basement but we also have a sloped lot and have a walkout basement. We jade a lovely large covered deck with stairs to the basement level too. Wouldn’t change it.

Are these "two designs" designed specifically for your site or are they "two designs" you are planning to potentially plop onto your site?

Sometimes the location of your house can be located on the lot so that a walkout is less necessary. If that's possible I'd vote for the larger single floor living area. If you have the topigraphical map for your lot post it.

Mrs Pete exactly what information are you wanting to know?

Well, you're asking, "Should we go with Plan A or Plan B?" but all we know is the size and general shape -- that's very little to go on, though -- as Mark said -- that opens you to criticism you might not want to hear.

Last custom build was walkout due to lot slope. I also wanted a basement so we picked that lot. More recent build was a pretty flat lot - we used a slab.

The connection to the outdoors is really nice - we enjoy the yard much more. No stairs to go pick herbs. We step down 4 inches or so to the patio and then the grass is an inch below that. Ditto for the garage to get to the cars. Also much easier to plant for privacy but this may not be an issue for you.

Go flat or go home I say (but sound like the lot may be purchased already)....