[EliRivers]

For example, the size of bedrooms, bathrooms, kitchens, closets, and garages has increased greatly in the last 100 years.

Have you been to the UK recently? :)

I don't know how much of an increase there was from about a century ago, but for the last few decades it's very much been going the other way. But the UK is something of a basket case when it comes to housing; people want to spend all their money on a mortgage.

Tangentially related, not long ago a minister suggested that people could keep a "jerry can" or petrol in their garage and was roundly mocked not only for the fire hazard, but for the casual belief that everyone has a garage.

[observation]

Personally I've always felt the existence of the garage to be an underrated contribution to American innovation.

I don't mean Americans aren't aware of it, I mean that sort of thing never comes up when Europeans discuss how to increase innovation. They will produce 'e-centers' and 'hubs' but I think most of the good stuff just comes from some people screwing around, probably with some things that don't rate much fanfare or seem adequate for a proposal.