Dear weedyacres, We're planning a full bath for a miniscule space, so I'm really interested in your post. Could you give any more info about the Hong Kong bathroom: where is the shower in relation to the sink?, what are the dimensions (more or less) of the shower?, any more pix?, sketch of floorplan?, etc. Thanks in advance!

I posted this as a somewhat tongue-in-cheek solution, as I doubt it would meet code in the US.

But FWIW, what you see is what you get. Toilet to the right, sink to the left, shower above the sink. You can see the water control knobs above the sink and the reflection of the hand-held shower head in the mirror.

A real-live wet room. :-)

Wet rooms are code compliant in the US although they might have to be a bit larger than this. Technically, except for some obvious practical and safety issues, residential design, particularly in existing structures has a certain amount of leeway when it comes to compliance: residential baths don't have to meet ADA requirements,for example, and one sees non compliant decorative stair rails all the time, with openings much larger than the 4" ball guideline.

I looked at a house whose only bath was a wetroom and it was some 50 odd inches square and the entire house was 11 feet wide.

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.

Thanks, all, for such helpful and informative responses. Special thanks to mongoct for so many detailed measurements. We're several months away from our bathroom project, but this information will give us lots to consider as we begin planning. Thanks again --

My son is living in S. Korea, and while I haven't seen a picture of the bathroom in his apartment (I think that it's too small for him to take a picture of), I believe that it is about the same size as the one that weedyacres posted. He needs to make sure that all of his bathroom needs are taken care of before he showers, since the entire bathroom will be wet for hours afterwards.