It is possible to have windows on the garage side if the the garage roof is low enough to allow for sensible window placement. When the side elevations are sketched out, it will be obvious whether it will work or not. As for dimensions, and working in multiples of 4', I have found that it doesn't make all that much difference in the overall scheme of things. The worst case would be to a bit over a multiple of 4. I always go a bit under to allow for building errors. If you went exactly 32', and they screwed up and it came out 32' 2", you'd have a problem. Also, tongue & groove floor decking, such as Advantech is 47-1/2", not 48. I didn't know that when I built my barn to 28' wide, and had to waste a whole row of sheets, as a 3" strip won't work on a structural floor diaphragm. The safest thing to do would be to go about 31' 6", which would allow for minimum waste, but a margin of safety. All that being said, once you get inside, all of that careful dimensioning is for naught, as the interior dimensions won't be nice neat multiples of 4. You can drive yourself nuts trying to save a few hundred dollars worth of materials. Our house is 33' 4" X 43' 4", because I worked in standard units for ICF. I didn't generate all that much waste, and found uses for much of it. If someone else is doing the building, they'll just keep filling the dumpster. Labor is a lot more expensive than materials. Designing a house with a simple shape and moderate roof pitch will go a lot further towards saving money.

I think some high transoms are a fine idea but I would put them together a bit more so they don't look so busy. Send us pictures of the hutch and bookshelf. Could they be grouped together with some art or a plant on either end? Breaking up that large wall could be done like this... (bedroom but this was also the design for our dining room). Make sure to allow enough space for your hutch. You could also choose to build out a space to make the hutch look intentional. I would take some time to draw furniture on that plan. It appears to be both quite small and also wasting space... The entry door in the middle of the family room seems out of place. Is this the main entrance or access to a deck?

You should be asking more questions than just windows. Such as why you'd put the pantry on an outside wall and on a corner. Corners are best for public rooms and bedrooms so those rooms can get windows on two walls. Also why you're placing the laundry room so far from the bedrooms considering bedrooms are where the majority of the laundry is generated. Also why do you have such a small enclosed kitchen? I'm not saying you need an open kitchen but this one is not even laid out well when you consider where the sink is in relation to the dining room. The sink and the fridge should be closer to the dining room and the cooktop should be the furthest away and out of anyone possibly walking by. If you plan to have a seating grouping around a tv in the living room, where will it go considering you have entrances on two sides of what is just a 5'-6' wall. And it means you'll be walking through the seating area to get to the master bedroom because NO ONE walks around. Everyone takes the shortest route. Why do you need an 18' long dining room? That's lots of wasted space for what? What is the wasted space next to the tub in the master? Where will the bed go in the master with all those doors? The mudroom will be tight for more than one person when you consider the bench/shelves are 18" deep. That only gives you 4.5' of walking space. Lastly the laundry room is 6' wide. Machines stick out a minimum of 30" and usually a few inches more. So that means you have a grand total of 4' to maneuver in the laundry room. If you have side loaders, that means if you open the doors you can't even maneuver around the machines in the room. Like I said, windows are the least of your problems right now. The best houses do not have fat roofs like your house. The best houses are designed in an L, I, U, T or H shape. The best houses have windows on at least two walls in all public rooms and all bedrooms. The best houses do not have utility rooms, pantries, etc taking up prime real estate on corners. The best houses are only 1-2 rooms deep and that does include porches, garages, etc. The best houses have a central "spine" so it's easy to figure out how to go from room to room.

I hear ya, I have a 1 and 5 yo. Life is crazy! I still stand by living in the house first. I learned a lot about our house in just 3 months. I wanted to practically gut it before move in. My ideas on what we needed and what we didn’t changed drastically. Things I didn’t consider became number 1 priority. We ended up needing to tear up our basement because of an unforeseen water issue. That took unforeseen money out of our budget. Lots of money would’ve been wasted and I would’ve been really unhappy if I had done the remodel before living in it. It’s hard with kids, but you want to have a house that you love and functions right in the end. A lot of cash, blood sweat and tears goes into a remodel.