Window boxes that really grow things are usually custom made, or high end are considerably larger than the so-called "window boxes" from big box stores. But you don't really have a place for them. Consider that window boxes are not mounted at the bottom of the glass but somewhat below that level so that there is room for plants to grow and come up to the glass, or a little above it ... instead of starting at the bottom of the glass and covering half of the window. In fact, your windows are low enough to the ground that by how you arrange landscape plants, you can plant them in the ground and achieve the window box effect. If you look at any of the sketches in which I've offered planting recommendations in some of the other threads, you'll notice that I commonly use this technique. It is vastly easier to take care of plants in the ground than in a window box, so if the window is low enough to the ground, it's the way to go.

I lived in an apartment that had 14 foot ceilings and between the high ceilings and the orientation of the windows (directly behind the seating area), the size of the windows (jibs that opened all the way to the floor) and the presence of a boardwalk style walkway right outside these windows, --we both felt kind of vulnerable sitting there watching TV. I would have felt much better had they maintained the other entry door to the apartment because the room would have been oriented in a way to better "protect" the occupants. (I lived in the back parlor of an 1840ish house that had stepped out onto a piazza, and the back had been dug out, thus the boardwalk) Conversely, the lofted portion of this room which had a 6'7" ceiling was oppressive to sit in because the ceiling with it's heavy mouldings seemed to press down on one's head. We were much more comfortable in the apartment we owned on a higher floor that had ten foot ceilings with an entry door down a 20 foot hallway. A large amount of space was dedicated to this hallway, but it really made the difference having this Inside the apartment rather than Outside the apartment as a public hallway even though we would have been the only ones using it regularly. That apartment really felt like a house in comparison. The similar things that I don't care for in McMansion type design are the undifferentiated space, furniture floating in positions that don't feel protected, rooms that are only irregularly contained by walls, and have amorphous boundaries. I personally find rooms that I can't define by a known shape unsettling.

The great thing is that a house can have nice big windows and still be well-insulated because of improvements in window design and, more importantly, glass technology. On the flip side, one must be careful to select windows with the appropriate thermal characteristics that consider the location of the house and positions of the windows. One can turn a well-insulated house into a furnace by installing south- or west-facing windows that don't handle solar heat gain properly. I've read that super-efficient houses in even cold climates can become overheated by their west-facing windows.

(Note: I started this response this morning, hopefully none of it is outdated! Darn work got in the way!) In addition to what others have stated... Move the DW to the other side of the sink. Right now, the DW is in conflict with the range -- a dangerous combination unless you have very wide aisles (51" or more range handle-to-island counter). Move the DW and sink as far to the right end of the island (right on the diagram you posted) as far as you can so you have more counterspace for prepping in front of the range. Right now, your Prep Zone (non-DW side of the sink) is located too far away from the refrigerator & range and has the DW & Cleanup Zone (DW side of sink) in the path b/w the Prep Zone and the refrigerator & Cooking Zone (range). This will cause a lot of zone-crossing, something that should be avoided if at all possible, and it is possible in your case. Then there's the barrier b/w the current Prep Zone and the refrigerator.... The island is a "barrier island" b/w the Prep Zone and the refrigerator. Moving the DW & Prep Zone to the range end (left on the diagram) of the island minimizes the "barrier" issue and brings the Prep Zone directly across from the Cooking Zone. The island can now be used as a landing zone for the refrigerator -- putting food directly from the refrigerator to the Prep Zone in the island. Move the refrigerator over about 13" and install a 12" utility or pantry cabinet b/w the wall and refrigerator. Right now, you will be unable to open the refrigerator fully for full access and cleaning. The refrigerator doors need to extend beyond all items adjacent to it within 12" or so -- counters, cabinets, walls, etc. The other option is to shorten the wall adjacent to it so it only covers the refrigerator box and not the doors. Sink placement -- centering the sink on the island is usually not recommended as it chops up the work space. Instead, as recommended above, move it over, putting more workspace where it's most useful. Seating -- be sure you have at least a 15-inch seating overhang for the seats. Sitting with dirty dishes "in your face" (which happens when the Cleanup Zone is in the island) is not pleasant, so put as much space b/w the seats and the back of the sink as possible! Plus, 15" is the minimum clear leg/knee space/overhang recommended for counter-height seating. 18" would be better, but I don't think your Kitchen is deep enough for that. Aisles...strive for at least 48" between the range's handle and the island's counter overhang and 54" between the island and the cabinets behind the seats as that is probably going to be a busy aisle and you have cabinets and workspace behind the seats. Note: Aisles are measured to/from the items that stick out into the aisle the farthest -- counter overhangs, appliance handles, etc. They are NOT measured to/from cabinets as the 24-inch depth used for cabinets only includes the boxes. It does not include doors/drawer fronts or counter overhangs. Note that "recessed" hoods do not work well unless they are very oversized and very powerful. They have to work against the FOGSS (fumes, odors, grease, smoke, steam) spreading out as they rise. The higher the hood, the wider the spread. Unless you have a fan that is strong enough to "grab" FOGSS quickly, they will have spread beyond the hoods ability to capture them. Grease is heavy enough that I doubt a fan that high off the surface will capture any of it. Also, useful hoods have a "cup" to capture the FOGSS so they can be vented outside. Speaking of venting -- I assume it's exterior vented and not exhausting right above the window. Personally, I would not want sunlight in my eyes while trying to cook - what exposure is it? If north, glare may not be an issue. If you're changing windows anyway, why can't you flank the range with windows? It's a much nicer (and higher-end) look.