Step, Slide or Boom?

I have a sister nicknamed "Boom" because as a wee child, she fell down the thirteen stairs in our house.
Boom, boom, boom, boom, boom, boom, boom, boom, boom, boom, boom, boom, boom.
She was okay.
But Boom could have avoided both her bumpy fate and unusual nickname if our parents had installed a slide in the house.How cool would that have been? And as you can see above, that's what London architect Alex Michaelis did for his kids.
The beauty of these kinds of stairway additions is that when...