David at LifeEdited trolls in one of our favourite sources, Modern Mechanix, looking for all the great old designs for living in less space. This two-room trundle bed idea would still roll, a great way of hiding the spare bed. I grew up on a trundle bed and should note one problem: one of the mattresses is usually bigger than the other and one of them cannot use standard sheet sizes.
LifeEdited hit a few that have been on Treehugger, like the Folding bathtub, but missed some real favourites:
In 1866, Charles Hess of Cincinnati, Ohio received US Patent 56,413 for an "Improved Combined Piano, Couch and Bureau" that was designed "principally for the benefit of hotels, boarding schools, and apartments which are used for parlors etc. in day-time and yet required for sleeping rooms at night"
in 1951, science fiction author Robert Heinlein built an entire house around the idea of easy living in small spaces, just 1150 square feet. It had transformers everywhere, with a dining room table that slid between the kitchen and eating area, to "eliminate the time-consuming chore of carrying dishes to the dining room table before dinner a meal and then carrying them back when the meal is finished."
Every sofa flipped out and became a bed. Popular Mechanics concludes with an explanation of the high cost of construction that we have been using ever since, and certainly applies to a LifeEdited:
The house cost a little more than $20 per square foot. That sounds expensive but really isn't. For one thing, cost per square foot would have been less had Heinlein built a larger house; he packed all the expensive kitchen and bathroom fixtures into a small residence. For another thing, much of the house was custom-built on the site because some materials weren't available in the shapes and sizes he required. Most important of all, he had no furnishings to buy when he moved in.