We just finished the layout stage of our basement renovation. Our basement is almost exact the same size as yours so I'm very interested in seeing your progress! We chewed on plans and ideas for more than a year. We only came up with a layout we both feel good with once we finally figured out what we really want to use the basement for and what should be possible in the future. Our house is one bedroom short for our family so we really need a bedroom or sleeping area in the basement. Our house only has one bathroom (one toilet) for 5 people so we need an extra bathroom too. We have an exit to the garden in the basement so we wanted to have some kind of mudroom, laundry and mechanical room needed to stay downstairs too. First we thought of making a bedroom for or oldest son. But the square footage we have to work with is not big and making a bedroom, bathroom, mudroom and mechanical room would divide the space in a lot of little rooms and a hallway which takes in space as well. Furthermore, in this area basements are typically used for recreational functions. So we fear the resale value of our house might decrease with no obvious recreational space down there. We decided to turn the basement into an open concept bedroom/office for ourselves and have the bathroom for ourselves too. This way the basement will be our own little studio, the kids will each have a bedroom and one bathroom upstairs. When the time comes that our kids move out, we can simply take our bed out of the basement and replace it with a couch or two to turn it into a recreation room. I hope this can help in some way! Maybe you too can combine the functions of the rooms you want, like: bathroom/laundry or recreation room/guestroom ? This is roughly the new layout of our basement, the dimensions of stairs and doors are a bit off but you'll get the idea :)

Millworkman, the ceiling height is 10ft. The land is 6 acres of flat ground. The plan is to have a walkout basement and build up the front. Our builder has been working on all the other things, he mostly just wants me to have an idea of the flow I’m looking for. But I’m having a hard time seeing it. Adjustments will happen as we continue the processes. As far as window placement, there will be many large windows all across the back wall.

Ask the people that gave you the plan. Yes I have seen them before. Generally walls, doors, fixtures, etc. denote future layouts that may or may not occur in the initial building process or ever. Only the people that had the plan drawn that way knows for sure.

I have a finished walk-out basement with two windows about the size you mention, and a slider. Unfortunately, all of the windows face north and the slider is under the deck, so it's still pretty dark. So as to the lighting, it depends on which direction the windows face as to how much light you will get. The other thing about basements is that it's hard to keep them as warm as the space above. Other posters have mentioned this and I've certainly noticed it. So if you can, have a dual HVAC system such that they operate separately on each floor and be prepared to run around opening and closing ducts when the seasons change. I also hate Jack and Jill bathrooms. We had two in our last house and changed both of them so they weren't anymore. Now we have one in our current house that can't be changed. :-( But we're empty nesters now so we don't really care. :-)