Exterior:
Materials:
The materials you've used are absolutely acceptable. However, you can still experiment a bit more with the materials, instead of using only logs and sand in the walls, perhaps try to variate a bit more with f.ex. sandstone.
When it comes to the patterns you got in the walls, you might want to rethink some parts. I saw quite a lot of places where you have the top/bottom side of a log facing a window, which looks quite ugly, IMHO. I'd suggest that you either doesn't place logs next to windows, or rotates the logs so that the side faces the window. Otherwise the patterns you have looks nice. Perhaps try to place logs diagonally, not just vertically/horizontally.
Shape:
Your shape is what I would consider to be one of the biggest flaw of the outside. You've chosen a good shape for your first floor, but when it comes to the second floor, you follow the shape of the first floor a bit too well. I'd suggest trying to make the shape of the second floor more different, f.ex. by adding a small overhang on the north side.
Overall your house is just two "T"s stacked on top of each other, one longer than the other. The effect this has on your roof, is that you get one long section of the roof which is quite plain, with little to nothing interesting on it. That's something the overhang I mentioned earlier can help you solve. When it comes to the ends of the roof, well... things get weird. From the north side, ground level, your roof looks more like a banana than a roof. I'd suggest trimming off at least three blocks of the roof on both sides, and/or add some supports to hold up that roof. I'd also suggest you avoid curving the roof as much as you do, one block or even two up should be more than enough (This applies to the third roof end as well).
The open wall to your balcony, I suggest that you close it and have a door outside instead. A hole in the wall like that looks weird.
Windows:
Your window distribution on the house seems very nice, you've got a good amount of windows on all sides. No side seems to have an excessive amount of windows, or too few. You have also placed the windows somewhat unpredictably, which is great. Gives this small touch of chaos you'd expect to find in a PV house. However, some of your windows feels a bit too large. I personally try to keep windows at most 3*2 blocks, 4*2 looks a bit silly IMHO.
Decoration:
You've done a lot of good stuff here, I like much of what I see, especially the eastern side. Your leaves hanging from the roof looks quite nice, and the amount of grass/flowers in the garden is very good. However, the amount of leaves you've used is pretty intense... I'd suggest removing a large quantity of the leaves, especially where you have huge clusters of them (Near the entrance and the north-west corner). Having a hedge that goes all the way around the house looks a bit silly, so I'd suggest removing the parts that's not near the entrance or the west side. The leaves that hangs over the path to the entrance are a bit excessive, I'd suggest removing them.
Overall the exterior isn't too bad-looking. Still a bit to do here, but you seem to have this under control.
Interior:
Kitchen:
Your kitchen has the essentials, and a little bit more. Looks alright, but somewhat cramped. Good level of details.
Your chairs, however, are a bit basic. Adding some more detailing to them might be an idea.
Important: Your first floor contains pretty much the kitchen and two tables + chairs. I'd suggest removing the table closest to the door and add entrance-specific furniture there instead. More details, such as a carpet can help a lot.
Nitpicking: Your stairs has some "antifall" installed, but doesn't seem to be that effective. I'd suggest trying out alternative ways to prevent falls.
However, on the second level there is no fall protection at all. I'd suggest you add some there.
Remember to add doors to the outside.
Area next to the balcony and corridor:
This area is somewhat empty, I'd suggest adding more items here.
Why are so many doors missing? There's no doors to the bathroom or the bedroom.
The staircase here gets the exact same comments as the other staircase, in addition to one thing. Try to avoid awkward turn you got in the first step, adding one more block would solve that issue. You got the same kind of issue on the top of the staircase, the ceiling is too low to climb up before having to make an awkward turn. Try to modify the staircase a so that walking up and down is a bit easier.
Bedroom:
Looks quite alright. I like the wardrobe.
You might want to avoid using this many bookshelves.
Bathroom:
You've got only the essentials here, and minor details.
Why are there so many bookshelves in the bathroom...?
Stone blocks aren't the best blocks to use unless you add something else to them.
Attic:
No doors here either?
Bookshelves, bookshelves everywhere.
Nitpicking: Your coding style needs more work, looks awful. Allman style is the way to go ^^
A bit empty in places, more stuff would help.
Overall, a bit weaker that the outside, but with a bit of work it will work. Keep practicing and you'll get there!