If you were designing (or have designed), you're "dream house" what seemingly mundane or easily overlooked feature is very important to your design?

There are lots of "awesome" things we would want to put in our total dream house (I would want a very large Library, like the one in Downton Abbey). There are even more entirely unrealistic features (who wouldn't want their very own replica Bat Cave?).

I'm looking for the blissfully simple feature, that would be very important to you, but you think most people wouldn't think about.

For me I would want all the toilets in the house to be the ones designed for wheel chair accessibility. Not because I'm in a wheelchair, but because I'm pretty tall (6'3'') and just find them much more comfortable to sit on because they're taller than you're standard toilet.

Anyone else? Even better if you've gotten to design you're own home and ran across something that was very important to you, that most people thought was trivial.