[RDDavies]

Unusable floor space, higher than necessary vertical space. Seems largely inefficient to me. I don't need ten feet I'd be very happy with 8. This could theoretically fit 1/6 more people into the same amount of "square land" without any drawbacks other than cosmetics.

Inventions I'd like to see: Solar / radiant heat rechargeable thermostat. Annoying to have to replace mine with a watch battery once every six months.

Dual-filament bulbs that only fire one at a time. First one burns out, second one still provides light (perhaps at reduced output?), but indicates it is in need of replacement somehow. Not necessarily needed for standard bulbs, but the recessed lighting in my current place needs this badly. Bulbs are expensive and I don't keep them on hand if I'm not going to need them. But when I do need them, I'd like to have a bit of notice to get them before I lose light in a certain area of my home.

Flux (brightness / color adjustment for OSX) for all lighting in the home. Adjust amount of lighting based on time of day.

[akavi]

Regarding your first point, I've lived in small apartments with high ceilings (12 ft) and small apartments with low ceilings (~8 ft, if I remember correctly). The low ceiling'd one actually had higher square footage, but felt noticeably smaller and more cramped.

Yeah, the space isn't useable, but that doesn't mean it isn't useful to the psychology of the human's occupying it.

[brudgers]

" This could theoretically fit 1/6 more people into the same amount of "square land" without any drawbacks other than cosmetics."

In the US, the primary constraints on density tend to derive from land development regulations - particularly those relating to parking (non-surface parking is expensive), direct limitations on density (dwelling units per acre) and limitations on overall floor plate area (floor area ratio).

Overall building height is somewhat uncommon as a constraint on density and tends to play less of a role than floor-area-ration in determining how much space can be built.

[shiftpgdn]

Flux bulbs would entirely possible now that LEDs are becoming common place. Unfortunately it'd be tough to solve how to have all the bulbs change color temperature at once based upon the time of day.