You have a good start with a schematic and ideas about how you will use the space. I notice the "Entry" so either the basement has outside access or goes into your garage. Not certain where the main steps enter but I suspect into the larger space.

Are you DIYing or hiring the work done? The biggest obstacles are the supports (I'm sure you know that). Most likely two nearest the furnace will be enclosed within a wall. Since you mention bookcases, I would try designing those to enclose some of the other posts.

Waste no space. Make certain any hidden "nooks" can be used for storage so make them accessible.

I suggest to many that they draw the space to scale including walls. Begin with graph paper, pencil and eraser. This will save lots of building time because you'll have a plan. Here are my suggestions for planning:

Place 2" XPS foamboard against the foundation and build walls against the foam. Finished with drywall you have lost 6" of space all around.
Place masking tape on the floor to get a feel for room sizes. Interior walls will be 4.5" thick.

Place X's of tape on the floor where you wish canister lights. Consider placement of electrical outlets and switches. Have plenty of circuits/outlets for table/floor lights, heater(s), appliances and convenience.

I agree with supplemental heat. We installed an electric fireplace under the house ductwork. Ours emits up to 10,000 BTU's and requires 220 volts. It's used spring/fall when the furnace is not necessary for the main house. The illusion of a fire can be turned on anytime.

Install a back-up system in event of sump pump failure.

Consider replacing inexpensive builder quality windows, or fitting storms - this will goes miles toward making the space comfortable in cold weather.

We would be lost without the clean-up sink we installed. Keeps the paint brushes away from the kitchen and is used for many tasks.

5 x 7 is larger than necessary for a Powder Room. Even 3 x 5 can be made to work but that is tiny.

Place a double wall around the furnace to contain the noise. Build it with 2 x 6 plates, then offset 2 x 4 studs so sound does not travel through the wall. Firecode drywall inside too. I also suggest installing a pan under the water heater so that when it leaks (and it will someday) your finished space does not get wet. Make sure access for servicing the furnace and water heater is there.

I'm linking an album of our basement which includes the plan. It's been posted several times so you may have seen it. Many of the photos have information provided below them to explain better.

Hope this helps. Good luck.

Here is a link that might be useful: Basement

The entry is from the outside, we have a walkout basement, it's a double door there.

We are DIYing - my DH and his friend (a contractor) will do all the work except electrical and plumbing.

I love the masking tape idea, that helps immensely! We are going to do that asap.

How many square feet does your 10,000 BTU fireplace heat?

Can you also tell me the make/model of your fireplace?

Our builder put Andersen 400 series windows in our basement so we are happy with those, I think they are better quality than a standard basement window.

Thank you for linking your basement, going to check that out right now and really looking forward to it since you obviously know what you're doing!

liptonjl

You have quality windows as walk-outs generally do. Standard basements most often have single pane ones which prove unsatisfactory.

Our electric fireplace is a Lenox, don't know the model # and would need to remove it to see the plate. It is auxulary heat, not primary. We have about 650 sq. ft. that it covers sufficiently keeping in mind that it might only need to raise the temperature 10 degrees F. Our main system is forced air and we have a couple vents. During the coldest weather radiant from the ducting makes the basement very comfortable.

Here's another thought for disguising the posts close to the walls. Make them part of a bar - even if you only place cabinets against the wall. Box out the posts, then you could frame a soffit at the ceiling for lights and a speed rack in between.

One more item for consideration. You mention an upflow toilet. Are you meaning one of the self-contained ones which don't require in-the-floor plumbing? Personally, since you're working with a "blank slate", I would bite the bullet and cut the concrete and do it right. Then your powder room placement is unrestricted, you won't have additional pumps to maintain and I believe will have a better install. I've yet to put the bathroom in our basement because I have been concentrating elsewhere in the house but that is the conclusion I have come too. My 2 cents.

I'm not a contractor, just a fussy DIY'er. I learned alot finishing the basement and gained a huge respect for architects and their knowledge about space usage. Good luck with your final design.

If you are pretty tech-savvy, I would highly recommend using Google's free SketchUp software for planning. My husband created all of the plans for our entire basement before we started building. I am a very visual person, and having the 3D software allowed me to see exactly how everything would look. It was so awesome to see our computer plans come to life as we finished the basement. It's defintely a great tool to help with planning!