Airplane business class doors offer new levels of privacy. Here’s why they might not be a good idea

(CNN) — Business class is becoming increasingly more luxurious, spacious and private. Whether it’s custom-designed seat and bed cushions, bespoke fittings and fixtures, or co-branding with some of the biggest names in luxury, business really is the new first class aboard many planes.

That’s especially true in business class mini-suites with doors, which debuted nearly 10 years ago aboard JetBlue’s Mint premium airplanes, and are now found on a dozen or so carriers including Delta, All Nippon Airways, British Airways and China Eastern, with more rolling out every year.

Doors make the business class experience better in two ways: first, they add privacy, and second, they avoid what airplane seat designers call the “brush past,” where a passenger or crew member walking down the aisle bumps into a seated passenger.

If you’ve traveled in business class, you might already be thinking of some of the seats where that would be particularly beneficial.

One might be the several kinds of staggered layouts where some seats are right next to the aisle, but others are well away from the aisle, on the other side of a little console table. Another might be the angled herringbone layout where seats face into the aisle and you end up having to avoid eye contact with the person opposite for the whole flight.

Privacy shells

Doors obviously help to avoid that. But while these mini-suites with doors are more private than many first class seats, the word “mini” is in their name for a reason: the space for each passenger is, while massive compared with economy, still smaller than first class.

Adding an inch or two to incorporate a door can really impact the amount of space that’s available for your seat.

That sure is a nice problem to have, you and I might think from our 17-inch-narrow seat in row 54, but every fraction of an inch of the cabin’s width is used, and on some medium-sized planes like the Boeing 767 or 787 and the Airbus A330 or A330neo, that can make a real difference to how spacious a seat feels.

So why do airlines choose doors, even on some of those medium-sized planes?

“There is undoubtedly a movement towards increased privacy on aircraft, flowing down from first class where the Emirates full height suite set a new standard, into business class,” Collins Aerospace’s vice president of aircraft seating sales and marketing, Alastair Hamilton, tells CNN.

“Most business class seats have had privacy shells for a…