Hi Chris:
See Section 8.2 The Mapping of Textures on the Sides of a Building on Pages 31 and 32 in:
"
Generic Buildings for FS9 and FSX" by Helli Hauck
http://www.fsdeveloper.com/downloads/generic_buildings_for_FS9_and_FSX.pdf
"
(Page 31)
8.2 The Mapping of Textures on the Sides of a Building
Luis Sà, the author of SBuilderX pointed this out.
We use a high WINDOW texture number 147. In Fig. 33 it is shown in layer 7
Fig 33
Fig. 34 shows a "standard" building, with sizeX = sizeY , all indices = 256,
Fig 34
It is remarkable, that only the display in the y-axis follows properly the texture.
(Page 32)
In the x-axis the direction is reversed.
Next we extend sizeX from 60 to 100
Fig. 35: Result of a longer X-axis
The display in the Y-axis stays the same.
But the mapping of the texture in the X-axis does not start at the corner but is shifted.
The last Figure shows a potential influence of a changed texture index X (from 256 to 512)
Fig 36: Result of a larger texture index
As can be seen, the texture index does not influence the mapping of the texture.
Doug Matthews (of ACES), when asked by Luis Sà (author of SBuilderX) about this, merely shrugged his shoulders with this comment:
"The code for figuring out the horizontal "starting point" (for the texture mapping) attempts to get doors on the front and back faces. It also involves a pseudo-random mechanism, which is probably why you're having a tough time.""
If you are encountering these issues when otherwise following all procedures that you ('
should have'

) read in the SBuilderX Help file and in the above document by Helli Hauck, for the buildings which are a persistent problem, you may need to use the default FS Generic textures and manually map those textures onto 3D MDLs made in Sketchup.
Alternatively, have you tried to simply 'place' Buildings already available in FSX default scenery object libraries: ?
http://lc0277.gratisim.fr/sceneobjects/airport_objects/index.html
http://lc0277.gratisim.fr/sceneobjects/autogen/index.html
http://lc0277.gratisim.fr/sceneobjects/
Otherwise, you may need to build 3D models entirely "from the ground up" in Sketchup.
You could first try using Morten's "
One Click Hangar" plugin for Sketchup""
http://www.fsdeveloper.com/forum/threads/one-click-hangar.424466/
I have not tested this capability yet, but have you tried using the option to save a screenshot from ADE which shows the footprints of generic objects along with other objects such as (most) scenery library objects, and use that as a background in Sketchup to create faces on the ground to be extruded into 3D models ?
And of course, by now you are familiar with how to utilize the usual procedure of importing an aerial imagery background from Google Earth, or an aerial imagery BMP output from SBuilder ...to create faces in the ground to be extruded into 3D models.
How many such buildings are you trying to create ?
If you are trying to create quite a
large number, you could consider using Arno's ScenProc with the aerial imagery building detection feature, or use the Building creation feature for autogen Generic Buildings that reads vector data from
ex: Open Street Map (or other source) ESRI SHP building location / footprint data files.
Hope this helps with exploring your options.
GaryGB