If the lots are very hilly you can't possibly design your house without choosing a lot. End of story. If you don't have a flat square or rectangular lot your home will have to be designed around the lot, not the other way around. Basically your best bet is to choose the lot with advice from your builder and/or architect and then start designing the house. I highly recommend getting advice from them because building on such lots come with their own challenges and complications. Their advice regarding which lot to buy could save you lots of time, money and headaches. Right now you're just doing pie in the sky doodling. We ended up choosing a challenging lot and my house floor plan didn't work out the way I would have designed it if I had just had a blank sheet of paper and sat down to design my dream floor plan. It will work well for my family but to make the crazy triangular lot shape work the architect had to do some stuff I never would have considered.

What tcufrog said. Pick the lot first. Even I picked my lot first and I'm on a flat piece of land. However, in my development, I chose the corner lot. If I had chosen an interior lot, it would have meant designing a completely different home.

Additionally, looking at your design. I don't like that your children at such a young age are so far from you. One upstairs and one off the kitchen which tends to be the noisiest room in the house? and the master off the dining room?

I like your plan! It's got a nice main living area and a great extra space. Baby's room, guest room, office, den...lots of potential :)

Something like this? Piano in great room (against entry wall) and sewing area in dining hutch. I squared off many of the angles...hopefully this will be less expensive.

I will third what the first two posters said. You need to have your lot first.

We just finished have a house built on a lot we purchased years ago - we thought that it didn't have too much of an upslope. We were a bit wrong about that. And, the building envelope is near the front of the lot. Between the requirement that the driveway enter the lot within a certain 15-foot wide place, and that the driveway have no more than a certain percentage of grade, the location and shape of the house and the garage was very much dictated by those other factors.

So, buy your lot first. Ideally, you will have a chance to check out architects at the same time, and then he/she can give you some input on the lot (we looked at other lots as well, and our architect gave us his input on those too). Give him/her your draft plan, along with your other needs, and let the architect put his/her expertise to use in fitting everything you want into a small house plan. (BTW, our house is smaller too, and I have a piano, and sew as a hobby, too, so needed to fit all of that in.)

lavendar_lass, pianos really shouldn't be on an exterior wall, it effects the strings and tuning too much. I don't see anywhere in the house that the piano would fit. Sewing area could go in the guest bedroom.

I know, but there aren't many choices. If the piano is on the outside wall, doesn't that mean it has to be tuned more often? My mom's piano has been on both...and it's going on 40 years old :)

As for the lot, it is nice to tailor the plan to the space....but this house is small enough, I would imagine that it would work almost anywhere. If you know the view will be out the back, you can flip the plan to take the best advantage of the light. There's not that much 'view area' just the slider and kitchen window.

I like that it feels like a cabin...and it would not be difficult to add a big sun/screened porch to the back, to take advantage of the views and add a little more space for the kids to play. Especially if the basement doesn't work out.

And, if the OP doesn't want an L-shaped sink area in the master bath...there could be access to a porch or deck off this space, too.

For what it's worth, this floorplan is approx 52x52. Our first choice lot is most likely this one... you can see how the house is small enough to sit on the flat area. Access to street is in the bottom right corner (an easement through someone else's property...it's kind of an odd lot but there aren't a lot of attractive lots in this area so beggars can't be choosers).

Views would be to the northeast. Unfortunately to the southwest is a hill that peaks approximately 100 ft higher than this flat area, so there isn't much southern exposure.

Won't make a final decision on a lot until we have an architect involved, but I do want to have some doodles to bring to the architect so we can articulate what we do/don't like in a floorplan.

For those concerned, I personally prefer to have babies on the first floor of the house (it's easier to check on them during their daytime naps) and on the same floor as the master (easy to check on them in the night). We keep a twin trundle in baby's room so our older child can share with her when he wants to, but he's very independent and doesn't need to be on the same floor as us. I'm not worried about baby's room being within earshot of the kitchen because I train my kids to sleep through the background noises of daily life. :)

Sewing space in the guest room is a good idea if I could make it fit---the room would just have to be bigger, or perhaps the closet space could be utilized.

Pianos against an exterior wall are a no-no, but I do want to ask my architect if this is something they can accommodate in a plan. Perhaps if they KNOW a piano is going to be on an exterior wall they can beef up the insulation, or put a central air vent closer to the piano...that sort of thing?

Oh...and I'm one of those sticklers that will never put a tv over a fireplace. The viewing angle just doesn't work for me! :)

8 ft of slope over 50 is the almost ideal scenario for a daylight basement. If you are sloping up in that same range, as it appears from the topography map, you may need a garage under plan.

I don't understand the plot map though. Where is the road / access? What will neighbor you?

That's a topographic map but I can't tell if there are any easements,set backs, or build lines. Have you seen the latest flood plain map? Our lot is challenging not just because of the topography but also because of the set backs.

If you're going for the smaller houseplan concept, then you want to make every foot count. Your guest room (used how many days/nights a year for guests) should be a multi-use room. Consider a murphy bed (that's what we did) or a sofabed, or even a futon, so you can also use that space a greater percentage of the time by having your sewing area there.

Just to take your ideas, possibly, in a whole different direction, if you end up with an upslope lot, you might end up with bedrooms and other space on the lower level, and your main living area on the upper level (which would be ground level at the back of the house).

As a family of four with a 2 and 5 year old, I'd rather have a windowed, small sitting room off the master that's just temporarily used for the baby and have the flexibility provided by having three small bedrooms upstairs. Especially after stomach flu recently sweeping through our house starting in thevery wee hours of the morning, I'd want the option of having a bedroom close to the children's bedrooms.

A new house built to currently available insulation and sealing standards shouldn't make any difference to a piano. In the old days, outside walls changed in temperature noticeably. Now days, that shouldn't be the case. I've gone around with a surface reading thermometer in our new ICF house, and there is only about a one degree difference between interior walls and exterior walls- and that's the wall surface itself. If your exterior walls are that cold/hot, you should be re-thinking the construction method. I would of course avoid being near a window, at least if sunlight could hit the piano. I'd be more concerned about an HVAC duct blowing on the piano.