Yes you expend extra indoor space on hallways and elevators but that’s around 25% of the building space and is often kept at a temperature much closer to the temperature outdoors.

You do drop tree cover, which is a serious help on some homes (the ones which are lucky to still have that carefully planted tree tanding).

(Consider my use of “heat” to mean heat transfer. Direction isn’t particularly important).

You get quite a few gains though: Your only losing heat to the outside on two sides instead of 4. On all but the top floor you don’t have to pay the costs of heating the roof.

If you own your apartment that’s where most of it stops.

If you don’t you have extra costs because land lords are cheap and don’t give a rip about efficiency. You won’t find on demand water heaters, efficient refrigerators, or lots of insulation in most apartments.

However, you’ll still find lower utility bills. It’s difficult to find a house which will get as low of utility bills as my apartment. We found one once: It was 25% smaller, had a heat pump, and was previously occupied by folks who were obviously frugal.

So I don’t know where this study is coming from. Here in the midwest of the US an apartment works out to be more efficient with respect to utility bills. It’s obviously more space efficient.

The major suck factor on apartments is the lack of green space to grow things. This isn’t at all unsolvable but it seems to be a feature that no apartment dweller wants.

High rises can have some utility advantages they rarely end up with, and those will come as the market dictates them (as energy prices rise):
Geothermal makes sense for big buildings. For your house it’s a lot of expensive work.
Solar makes more sense for the landlord because he’ll own the building long enough to get his investment back (I’m actually shocked I don’t see solar panels on every apartment and an electric bill split between the landlord and the electric provider).
I’m less sure about this, but I’m guessing that the huge parking lots on apartments give a good shot at an effective mid sized wind mill (the return on investment is quicker here than solar).

There are also financial advantages: We wouldn’t have so much of our economy wrapped up in our shelter if we didn’t all require a single family home . US resources are finite and we can only invest so much. If you take it away from housing it’s going to go somewhere else.