Use brick wall splines to make the warehouse.
That would be painstaking to stack wall spine right over the top of each other, corner to corner.
Well, here's what I settled upon to make my final warehouse:
6 x Warehouse loading docks,<kuid2:70337:27040:1> by martinvk, A 4 x 16 x 32 module
Wall 10m dark stone weathered,<kuid2:283805:37921:1> by tmz06003, Original work by pgmetcalf reskinned by tmz06003 with permission from pgmetcalf.
8 x Streetlight-no pole,<kuid:134105:3000> by paulzmay, Streetlamp without pole, designed for attaching to tramway overhead poles, or walls. This version is a scenery object for you to place anywhere. Uses corona by CloakedGhost275.
2 x Door 7x3,<kuid2:117948:100117:1> by nawlins, Door 7x3. Original by johnwhelan. Reskinned with permission.
3 x Roof Ventilator,<kuid2:106916:10124:1> by gfisher, An industrial roof ventilator.
Cablebox,<kuid2:2000:37000:1> by zyryz, Cablebox in spline mode to lay beside the Danish rails that hold cables for the overhead wires
The six warehouse modules were stacked three high by two wide. You wouldn't believe how I got them all aligned at the corners.
The dark wall spline formed the new tall 4 meter-high freight doorways. I used the original short doors on the warehouse dock modules as a template for placing the new doors. The original dock doors were ridiculously short: clearance too low for tall forklift booms. I then rotated all six of the building modules so the original doors are hidden; they all now face inward toward the middle of the building interior.
The cablebox spline was used as flashing about the rooftop edges. The rooftop ventilators cover the small seam line spots in the middle of the roof where the lines are broken, don't meet exactly in the same places end to end.
That
cablebox spline, by the way, has a million and one uses for Trainz route building. I discovered it purely by accident while searching for "cable" spline to string across telephone poles. I use it a lot for landscaping trim: concrete curbing, borders, flower boxes, tree trunk base trim, children's playground sandbox border, parking space bumpers and whatnot. Building flashing is my latest use of it. See th round sandbox in the picture with the children's merry-go-round in the middle. Cablebox spline leaves a serrated "Skilsaw teeth" pattern about its edges when formed into a circle.