“Attic” has several usages. Traditionally it is a habitable story between the eaves and roof. An analog to a basement.

In a lot of contemporary construction it is an uninhabitable space between the eaves and roof. An analog to a crawl space.

In contemporary construction, habitable attics usually get listed as bonus rooms.

The GP is thinking of something reached by stairs. Nonhabitable attics usually are accessed by ladders or ladder like objects.

Additionally every single new construction I've seen in greater Boston metro area in the past 20 years has not brought in any pre-assembled elements from outside. Just piles of various sizes of lumber and assemble on-site.

(Edit: to be clear this is for residential construction which tend to be small 1-2 story buildings.)

Here's an example of a Boston area builder doing just that.

https://www.youtube.com/watch?v=2f4nqf_HgnY

Sure but I don't buy it's being done at scale. Even in that video they are mentioning an unusual design as a partial reason for the pre-fabbed elements.

Attics have been replaced by engineered trusses to hold up roofs. The trusses are made of.... wood. These trusses are also made offsite. This leaves very little room for usable attic space.

When designed for minimal load on the bottom chord, plate connected wood trusses cost significantly less. Not just for materials, but less to install because they weigh less.

> This leaves very little room for usable attic space.

There are things called attic trusses:

* https://design.medeek.com/resources/truss/trussgallery.html

You can also use (vaulted) parallel cord truss:

* https://www.dimensions.com/element/truss-vaulted-parallel-ch...

See also various other configurations:

* https://www.menards.com/main/buying-guides/building-material...

Even new slanted roof houses go for vaulted ceilings over having attics. Flat roofs are only viable in places without much snow (and were common in California in the past, so aren’t really a new thing).