> while using large windows to capture sunlight and heat works great in the winter
That's what awnings (or solar overhangs, or light shelves) are for. You block the high/hot summer sun but let in the low/cool winter sun.
> the idea that it has something to teach modern architects and builders is pure fantasy
Isn't the idea of mcmansions that they co opt smart classic design ideas, but use them in a manner which doesn't let them fulfill their function purpose(skeuomorphism)? So someone certainly has some things to learn
> That's what awnings (or solar overhangs, or light shelves) are for.
Right, this is my point. We already think about these things.
> Isn't the idea of mcmansions
I don't think McMansions, or whatever your favorite example of bad architecture is, shows that we've somehow lost knowledge. Architects and builders are aware of all of these things, but that doesn't mean there aren't still clients who want less energy-efficient designs for all sorts of reasons, like aesthetics.
We know how to build energy-efficient buildings that are appropriate for the location and seasons. We also know how to build buildings for other purposes, and are aware of the tradeoffs in how they use more energy. Energy conservation isn't the only goal in home design.
I think the idea with McMansions is that they are just tacky. Poorly aped styles. Columns that don’t do anything and are proportioned wrong for the load they are intended to look like they carry. Complex roofs that do nothing useful but “look fancy”. 100% style over substance, but with style that snooty people look down on.
I imagine that McMansions are generally about as energy efficient (per square foot) as other contemporary homes, though.