paulo
I think I know his plumber......

 
This guy though, thought it through........
 
 

Whoever designed round toilet seats was either a woman or they never tried one out to see how it worked... or maybe the toilet was designed and the seat was an afterthought. I do know I love the newer oval seats and I am not a big guy by any means, I weighed in at 119 pounds when I was 18. 175 these days.
My parents house has those old round seats and I have often wondered how someone who is portly or even "big boned" manages to sit on them without... how do I put this .... hmmm... er, what do they do with their junk?
Sorry, bad architecture!
 
Good architecture: The 2022 World Cup Soccer facility to be built in Qutar.

 
designed by Albert Speer Jr. Really...
 
J

spacey

sharke

mike_mccue

 
He can convert the 3rd or 4th step to a landing platform and continue the tread at a right angle down to the floor.
 
 

I think that's the only solution!

Spiral.

 
gotta move that light switch for the stairs up about 3 feet or so as well.... looks like it will be about 6" above the floor level on that 4th step landing.