Why are bathroom doors (at least in the US…not real familiar with other countries) so much smaller traditionally than the rest of the doors in homes? I am in a wheelchair so I tend to notice this fact more than most people as I have problems getting into almost every bathroom I have ever seen. and it is always just a few inches different than the other doors in the home. any ideas? just one of those things that bug me late at night. 
joe_iguana - I went to yank land earlier in the year. And noticed a few odd things.
Yes the doors.
The fact that it is offensive (or embarrassing to say toilet)
The Seats are soooo low.
The fact that water doesn’t spin … it kinda drops/sucked out of the bowl
I just looked - in Oz the doors to bedrooms are 800mm and toilets/bathrooms are 700mm.
Semi-wild guess… you do not need to take anything bigger than a person into a bathroom. Other rooms need the space to accomodate furniture moving eg beds, chairs and wardrobes.
I have a friend in a wheel chair. He had his house built will all doors extra large.
Trader - fyi - coincidently I asked a Canadian friend yesterday what they say if staying at someones house and they want to use the real bathroom (as opposed to the toilet).Do you say “Excuse me, where is the real bathroom?” or “Where is the bathroom with the shower?”.
Well, it turns out that all toilets in Canada are built with showers in the same room, so no confusion. Just thought you might want to know.
As you were…
antechinus: yeah, i wondered it that might be true, but one thing…toilets are not small nor are bathtubs…my personal theory is that perhaps because most homes did not traditionally have bathrooms until fairly recently(being the early part of the 20th century and as most families had outhouse till then and some much later) I figure that they had to add indoor bathrooms and didn’t want to build big rooms…maybe even converting a closet perhaps into a toilet? that would explain the british term of “water Closet” for a bathroom…just an educated guess…
A generalization is always a bad thing! 
For non-Canadians who need terminology regarding the bog / crapper / WC / bathroom:
Toilet: the thing that flushes. Virtually all Canadian homes have one. Our consumption of chamberpots is severely reduced now that we’re in the 21st century, and outhouse construction is in a major slump, throwing tens of workers into the unemployment lines.
Bathroom: Always includes a toilet and sink, usually a tub with a shower, or a tub with a separate shower. Sometimes just toilet, sink, and shower (for those who eschew tubs as "stewing in your own juice).
Powder Room: Toilet and sink only. Since wig consumption has also been drastically reduced in the 21st century, Canadian “powder rooms” are virtually bereft of wig maintenance facilities, so don’t be misled by this terminology.
WC or Water Closet: Could be the toilet, or could be a powder room. Not commonly used terminology; asking “Where’s the double-you-see” might get you shown to a pair of full-length mirrors instead of the pissoir.
Facilities: Genteel term for “crapper”, but possibly open to misinterpretation. Be cautious before asking your hostess if you can see her facilities.
Washroom: Another genteel term. Canadian washrooms will typically include a toilet. We just *hope[/] that you wash afterwards. “Washroom” is frequently used in an institutional setting - restaurants, gas stations, movie theatres and the like.
Hope that helps, eh?
So you lads don’t buy into the Commonwealth habit of calling the entire room the toilet (or at least public restroom facilities), as I saw in both New Zealand and the UK.
Shame, it seemed to simply things a lot…
Outside doors have to be big to get the refrigerator and stove into the house. Bedroom doors have to be big enough for the bed and chest of drawers/armoire/etc… Even if you wanted to put a coffee table in your bathroom there isn’t enough floor space, so the door only has to be big enough for a person to go through.