[nitrogen]

I visited a home once that was built in the mid 20th century on the assumption that electricity would become too cheap to meter. The original heating system was described to me as just a bunch of resistive elements strung in the attic. I think the house actually got an award similar to LEED (or maybe it was LEED?) at its construction.

[frosted-flakes]

My parent's late 70s house has something like this. There are heating elements sandwiched between two layers of drywall in the ceiling. It actually works really well, because it heats objects rather than the air--sort of like the sun on a cool, cloudless day--but electricity is like 4x the cost of natural gas so it never gets used. Also, the attic has insufficient insulation, so half the heat would go the wrong way.

[macNchz]

Oh yeah my (boarding) high school had a dorm built in the “electricity will soon be too cheap to meter” era and had heating elements set into the concrete floors. It housed like 50 students and used more electricity than all of the other buildings on the 500 student campus combined. The warm floors were very nice though!