The wood framework is underway and almost complete. These houses like many new houses have choices you can make about the floorplan. An upstairs living room (loft) instead of a 4th bedroom, A bathroom off a secondary bedroom, a den without a closet in lieu of a bedroom, decks, etc.
All options have a deadline date for each option category, once they start framing they cant change the configuration of the rooms or walls (usually the cutoff is just prior to framing). Plumbing options for things like laundry room sinks or additional hose spigots and electrical options such as ceiling fan outlets, cable, phone, wiring for surround sound and outdoor t.v., etc. are usually not allowed once drywall has started. At each stage, chunks of options are eliminated. If a house does not have a buyer by the time framing starts it has a harder time selling because some people want the 4th bedroom and not the loft. If it get to cabinets and appliances, the builder guesses or goes with the cheapest and that can turn away some buyers. With each option cutoff date that is passed, the builder’s odds of selling at full price diminish. When the house gets to what is called “standing inventory” (done except for flooring) they really panic.