I had someone who owned a beach cottage ask me a few weeks ago about the smallest you could make a bathroom like that one, a sink and toilet on a shared wall, with the entire room as a wet-room shower. We sort of broke it down this way: 1) The shower needs to be a minimum 30" square. 2) The toilet needs 15" to each side of it's centerline to each adjacent wall, which would be 30" between walls. The toilet also needs 21" of "knee room" space between it and the wall it faces. 3) The pedestal sink needs 4" between it and the adjacent walls. My building department also translates that as needing 4" between the side of the sink and the side of the toilet tank. The sink drain needs to be 15" from the adjacent side wall. You need 21" of standing space in front of the sink. Essentially, roughly figuring the width of the room, or the length of the wall that will have the sink and toilet from left-to-right: 4" from wall to edge of pedestal sink, 11" to drain, 11" right edge of pedestal (if using a 22" wide sink), 4" to edge of toilet tank, 9" to toilet centerline (18" wide tank), 15" to wall. Total 54" wide. That's figuring with a 22" wide sink. The sink drain still needs to be 15" from the adjacent side wall, so using a narrower sink would save you half the difference between the two. Example, using an 18" wide sink would save you 22" - 18" = 4" divided by 2, or 2". So your new width would be 52". The depth of the room is limited by the deeper of the sink or toilet, typically the toilet. Say 26" plus 21" knee space for 47" deep. About the smallest pedestal sink I've seen is a 16" deep by 16" wide sink bowl. There are some smaller, but using that, you'd need a room 51" wide by 47" deep. Now were you to keep the sink on the facing wall and move the toilet to the wall on the right, my code guy still wants 4" between the edge of the sink and the projected front of the toilet bowl. No overlap, so to speak. But he doesn't consider the sink footprint to be interfering with or impinging on the toilet knee space. With the 16" sink you'd need from left to right: 4" + 11" (required 15" from wall to sink drain) + 8" + 4" + 26" for a total of 53". For room depth, this time the sink plus free space will be the limiting factor, 16" deep sink plus 21" free space, or 37" deep, you'd need a room 53" wide by 37" deep. Those numbers above are with typically-sized fixtures and using code as it applies to me. We mulled over a few other ideas, but common sense and the inspector held us to those minimums. Choice #3? You could go with a corner toilet and a corner sink. You do shopping and you do the math! Wet room requirement: You need 2" vertical minimum from the door threshold to the floor drain. Meaning if you plug the floor drain and turn on the shower, you need 2" of depth over the drain before water runs out of the bathroom door (or under the toilet) and into the house or into the house's framing bays. Also, with a small bath like that, the door will usually need to open out of the bathroom instead of into the bathroom.

That's so true @needinfo1. I would think the shower curtain could prevent the toilet from getting wet though. Idk! @errant_gw I love those shelves, I will definitely do that! I didn't even think about cleaning. I love reclaimed wood so that will be great. I will post pictures when it's done!! Getting rid of the door to the guest bathroom is a good idea. It's a pretty far walk around though to get to the guest bedroom for someone who just showered and may be in a towel- they'd have to walk through the kitchen, living and dining room to get to their room. The layout would work a lot better in the bathroom though if we could get rid of the second door. Thanks for the ideas! this is the main floor plan that I decided to draw up one day. The square footage isn't right at all, I just guessed. But it gives the idea of the bathroom.

The "regular" bath layout that jensbride posted first is very similar to what our DD & DS shared for years and worked very well. The door, however, was a pocket style and placed directly across from the toilet. This allowed the vanity to be scooted around the corner to take up the whole wall. It leaves the toilet close to the tub, but with lots of elbow room. Our kids just learned to keep the door partially closed when the bath wasn't in use due to the "view".

It might help to show the adjacent foyer and hall areas you are willing to adjust. What you have right now seems good. I don't know if your mudroom includes your laundry. Do you really need a shower and or tub in this location? You could exchange the mudroom with the bathroom and reverse the layout so that the exposed wall would be across from the toilet and vanity.