Hello, I'm curious because I've seen some boeing concept/render with both side having the same amount of windows yet the production aircraft has one side with less windows than the other, why?
Concept:

from https://leehamnews.com/2011/09/15/boein ... e-program/
Actual fuselage

The two windows are part of the new stairwell design.



Boeing Mockup:
http://upload.wikimedia.org/wikipedia/commons/6/6e/Interior_Boeing_747-8I_staircase.jpg

so that's why they decided to get rid of them on one side?

They didn't get rid of windows, if anything there was a net gain of 1 relative to the 747-400. Check out a few pictures of the 747-400, and count the windows on the upper deck aft of the door:



You'll see there's 8 on the port side, and 11 to starboard. The staircase goes up the port side of the plane, so the cabin is longer on the starboard side, hence the additional windows. The last window on the upper port window belt is aligned with the first window past the second door on the lower deck, because they're in the same fuselage frame. On the starboard side, four windows overlap between the top and bottom belt aft of R2. Now look at that diagram: the front stretch is 160", and the aft is 60". With a frame spacing of 20", that gives us +8 windows in the front, and +3 aft. Now let's take a look at the 748i window belt on the upper deck:



15+2 on the port side, and 19 on the starboard side. So the starboard side is easy: 11 windows on the -400 plus 8 frames gives us 19 on the 747-8i, and the last four still overlap the first four frames past door 2 (all the pictures I can find have window blanks there, but you can see the outline on that Korean Air plane). So far so good. On the port side, we'd expect to have 16 (8+8) if it was the same as the -400, but instead we have 15+2. What happened is they stretched the upper deck, and in the process deleted one window from the aft belt, then added two windows aft of where the staircase emerges as DL_Mech pointed out. On the -400, that wall has no windows. There's no point in having window frames where the staircase roof is, so they left those 3 frames windowless, hence the gap. My guess is that the airier structure on the -8 staircase moved that roof line up one frame, but I'm not sure. What's noteworthy is the aft-most of the 2 port windows is further back than the last one to starboard (15 windows + 3 frame gap + 2 windows gives you 20 frames, vs 19 to starboard). If you look at this picture, you'll see that the last UD window overlaps the LD 5th window frame past L2 (there's 2 blanks if you look closely):



Looking at the picture of that mockup, there are 19 windows on the port side with the last four windows overlapping (identical to the starboard config), which could mean any of a number of things:
1. The image was based on a tech drawing that showed the P and S configs mirrored and didn't mention the blanks.
2. It was based on a render before detailed design started way later.
3. Someone thought it looked cooler to have a complete window belt.
4. Marketing made something up before engineering had a chance to take a look.
5. Something else.

FWIW, the decal makers on the Revell 747-8i kit (2012) got it wrong (page 13), so it may have been #2.

thanks, there are render on the boeing website showing concept with both side having a similar arrangement https://secure.boeingimages.com/CS.aspx ... rchResults The website also have the cabin mockup and thanks about the 747 8i from revell, I'm planning to get one with the old LH livery for my birthday(I got the siegerflieger in my stash that I'll do as a 747 advanced by shortning the fuselage)

Yeah, looks like they got it wrong in a few more places, see here: https://www.gulf-times.com/story/394468 ... rnative-to

When you say "747 Advanced," are you referring to the initial 747-8i version that was shorter than the freighter? According to Randy B, that was supposed to be 2 m shorter than the current one, so -4 frames. I'm pretty sure those frames were all in the forward section. https://web.archive.org/web/20141021092 ... venue.html

If you're interested in building models and knowing more about the window counts and other minutiae, I highly recommend checking out https://airlinercafe.com/index.php

I'm refering to the initial 8i version yes

Have I vision trouble or some windows are clogged on the other side of this model too (and if someone has a pic showing the other side of that model, please post it here)?

https://www.gulf-times.com/story/394468 ... rnative-to

thebunkerparodi wrote:

Have I vision trouble or some windows are clogged on the other side of this model too (and if someone has a pic showing the other side of that model, please post it here)?

https://www.gulf-times.com/story/394468 ... rnative-to

No, that one looks wrong as well, that's why I referenced it. The model maker likely just mirrored the layout of the port side to the starboard before printing the decals.

or it was configuration considered before but they decided not to retain it

I highly doubt they'd add an aft window and randomly block 3 windows on the starboard side, then their business-class pax wouldn't be able to see outside.

I believe where the two windows are located on the model (starboard side) is where the cart lift is located.