Not advice, but I can tell you what we have.

1st floor with 10' ceiling: Windows ~5' with ~2' transom above. Windows in kitchen are shorter due to counter.

2nd floor with 8'6" plate (ceiling heights vary): Windows ~5'

We're in the middle of building and I can tell you what ours are. I don't have any 10' ceilings, however, mine are 9' and the windows are either 5' on the front elevation, or 6' on the rear. That seems like it will be fine, the only downside I can see so far is they are double hung and I can't reach the top to lower without a step stool, but I am not that tall. The 5' ones one the front I might have liked to be 5'6", but oh well, to late now.

In our living area we have 12' ceilings with 5'6" windows with a 2' transom. They are higher off the ground than the other windows on the rear elevation.

Whats the house look like as pictures would help.

How far down from the ceilng are your windows being placed?
Thank you for your feedback.

Don't recall exactly, on the first floor I would guess somewhere between 4" and 7" from finished ceiling to the top of the glass in the transom (just enough for the trim).

We have about the same size windows as your architect is suggesting in our 10' ceilings. We left ~2' at the bottom and ~2' at the top. Once you get the trim on, they seems even bigger than that.

Upstairs, they aren't that big (we have 9' ceilings upstairs) but I can't recall the dimensions.

Thanks. I will try to see if going from 4'5 to 5' s a big price jump if not I will make all windows 5 and downstairs add a 1'5 transom.

The transom will probably be a big price jump.

Our ceilings are 9' 6", and the windows are all about 18" from the ceiling, or 8' off of the floor. The windows in the kitchen and MBR are 56", One MBR window is 70", and the living room windows are 73". The kitchen windows are 56" so they would fit over the counter by a few inches, and one wall of the MBR has 56" windows for privacy. The taller window will have to have drapes for privacy.

We were going to do transoms over the kitchen windows, as I wanted to do stained glass inserts, but the cost was prohibitive, and our door/window budget was already stretched.

Window heights can be all over the place, depending upon the style of house. In FL, all of our windows were quite high off the floor; you had to stand up to look outside. It's nice to have at least some windows tall enough so you can see outside when seated. Don't get carried away; I think glass below 24" from the floor has to be tempered.

Maybe ask your architect for some elevations, if you post them I'm sure you could persuade folks to vote on options :-)

Are these windows facing the front or back of the house?

We just finalized our design and our living room ceiling will also be 10'. Knowing that I was a fan of big windows and natural light our builder spec'd three 3' x 7' windows against the wall facing the patio & back yard. I've seen them in some of his other builds and really liked them. Wish we had a view of a creek or pond to look at, but you can't have everything on a budget. :)

Are your window tops aligning with the tops of the doors? It makes the window come down almost 2 ft off the ceiling? My architect says that's how it is usually done. 10 ft ceiling with 8 ft doors means windows will be 2 ft away from ceiling. Is that right?

Our first floor door tops (7' door) align with the window tops. Then there are transoms on the windows and exterior doors.