Before adding/deciding on windows, you need to look at your homes orientation (north/south/east/west). North facing windows do not receive any direct sun light (which might be good for your horizontal slits). East or West facing slits could provide a blinding light depending on time of day (requiring some type of window shade which may not be practical). South facing windows provide winter warmth and if properly shaded in the summer (through over hangs or desiduous trees) will not add unesaasry solar gain in the summer. My opinion of skylights is not that great, to many potential issues with them.

Is this a vacation cabin or full time residence? Do you have an architect already?

Yes, I should have mentioned the orientation. The kitchen wall is facing north, and the entrance wall is facing south, this is where the skylight would be. This is northern california and we get pretty extreme temps, 30s-40s in winter and 90-100 in summer, dry intense sun summers. So, I'm concerned the skylight would bring in too much heat in the summer, even with the low-E glass, though we'll have AC so that will mitigate the heat a bit.

"Is this a vacation cabin or full time residence? Do you have an architect already?"

This would be a full-time residence, and we are not using an architect.

"I would have as many windows as I could have."

But where exactly is what I'm trying to figure out.

Do you have a structural engineer? What is the purpose of the loft? Office work space? A vented skylight or whole-house fan may be useful in addition to the windows and screened doors, following modern building and safety codes.

Since you are planning without an architect, try reading "A Pattern Language" which deals with climate, windows, ventilation and so on. Although not designed for northern California summers, there are some good points about what makes an outdoor area comfortable vs. roasting.

Windows should be reachable for cleaning, openable for ventilation, and they should take advantage of the site's views. Your local building code will specify minimum sizes for egress. There are many, many threads on Houzz where people puzzle over how to shade windows that are high up and full of sunlight.

I like your 4th option for windows on the south wall centered on the wall next to the front door, provided your furniture still fits.

The loft will be used for office and tv area.

The loft windows will be on the north wall so they won't receive direct sunlight.

The 4th window option we are now thinking maybe a long low to the floor (like 18" up from floor) to allow a better view while sitting on the couch.

I'd enlarge the window in the wall next to the door from a slot to a proper-sized window. I'd use jalousie windows in the loft so you can open them for ventilation and still have the short profile. You might think about adding a big window or set of windows next to the front door. How come only one window in the bedroom? Taking into account furniture placement, you could still add a 2/8x4/6 directly across from the door. Also, extend the wall that encompasses the master closet and put a coat closet facing the fridge.

And apple pie hit on a good feature: a whole house fan. Lots of cool without a lot of money. Have you thought about solar panels on the roof?

Yes, to the whole house fan.

My wife insists she only wants one window in the bedroom, feels she would not use the second, but I think we need to rethink it because many have said a window on each exterior wall is the norm.

She also feel, relative to the walls at the door that she wants to have some walls be non-windowed to make room for shelving or furniture etc. She feels with such a small place we will need furniture for storage. Do you think we will?

A coat closet facing the fridge? You mean on the wall that is exterior of the bathroom?

I do not know the requirements but there is a minimum number of "square footage " of light required for each room. This is something that has to be considered. Where is Fred S.??

If that's to scale, there is no way that there can be even 6 feet of headroom in that loft unless that rendering is waaaay out of scale. And how do you get up there? Where will the stairs be? The bathroom door swing is impossible. The post is in a horrible place and would be completely unnecessary if engineered correctly (using the bedroom wall for support or a small wall at the kitchen cabinets, etc.).

That house looks like a maximum security bunker with all those mimsy little windows with slits for the guards to look out of. Even on the north side of the house (which gets no sun), the windows are skimpy. That place will be a cave if you don't open it up a lot. Do you have a real view in any direction? Maximize it.

Look at other houses, and look at house plans. There are basic, basic flaws in this layout. A small house needs to maximize space, and this doesn't do that.

Your idea of "extreme temps" is skewed. Philadelphia has 10-20 (and lower) winters and 90-100 humid summers, and we use all the glass we want. You do not have extreme temps, by any stretch. Even my 100-year-old house has at least two 12-foot-square (or larger) windows on each exterior wall in each room on 3 floors. Don't be afraid of windows.

Your master closet bumps out into the hall with the laundry but doesn't go all the way down to the corner. Extend it toward the living room, put a closet in that space with a door that faces out (not in toward the bedroom).

BTW, I've never heard anyone say they have too much sun coming into a room and wish it was darker. Go with the extra window in the BR.

to tatts, your response feels a bit angry and presumptuous. And not very constructive.

"There are basic, basic flaws in this layout." I have 720 sf to work with, show me a better layout, please.

Carolina,

Extending the closet to the corner would cover the door to the bedroom.

We will put an extra window in the bedroom.

Sorry, reflexive reaction.

Just go online and look for plans of 1 bedroom houses. You don't need to re-invent that wheel. If you're building a small house, every inch counts. There is an enormous volume of wasted space (everything that's open above 8 feet) that needs to be heated and cooled.

You have dead corners, a needless support post, no space for furnace, water heater, stairs. If the closet wall was made to be load bearing, you could ditch the post altogether. It's things like that that an architect would know and automatically design around.

But, most importantly: You are building a 2-story house (with all the added expense of building the second story) without actually having a 2-story house inside. It would be far less expensive to build (and heat and cool) a 1-story house with a larger footprint. A 2BR house on one level would be cheaper, more versatile and usable (office and TV area that could be closed off to separate the uses), and easier to sell in the future.

tatts,

What you are saying it true, mostly. But here's the thing, this is a granny unit, with a limit in size of 720 square feet. We would prefer a little bigger if allowed. The county does allow for a loft, and does not add that to the square footage, but they would if it was a second floor. So that is the impetus for this type of design.

I have not finished with the model, so there are many things that we will have that are not shown, like outside covered porch for water heater, and stairs. At first I thought the support post could add something, if it was decorative. But I agree at this point it is not working and needs to go. It isn't a trivial engineering matter though as the post is supporting the loft floor, and if I move that off the center of the beam then the beam will need to be bigger and that will cut into the already limited height of the loft. But it can be done.

Have you thought about putting the bedroom door on the other wall?

Where do you propose to put your dining area? Could you make the door near the kitchen a single instead of a double which would let you extend the kitchen somewhat and maybe put the refrigerator next to the sink run instead of around the corner from it. You could also have an overhang at the peninsula which would give you informal dining space. Also, don't forget a hood over the range, it's code and they won't a CO without it.

Make the laundry area part of the bathroom, put your W&D across from the sink and add a pantry cabinet or shelf space for linens, cleaning supplies, toiletries etc. It would be in one room instead of a bathroom and a hallway. Tell me, what is the footprint of this house?