Custom texture sets for buildings can be put into gamedata\buildtextures folder.

To do this if you want to create a Futuristic theme create a folder in gamedata\buildtextures called "Futuristic".

Inside the Futuristic folder you can place textures to overide the default ones used in the game. 
Each texture set is comprised of 16 different textures. 
Note each texture must be a 64x64x32bit uncompressed TGA unless otherwise stated.

The filename format is as follows..

Blank.tga 	- This is the standard blank Upper wall texture
Blank2.tga	- Alternative blank texture
FlatRoof.tga	- Flat horizontal roof texture
PointyRoof.tga	- Slated roof texture
Window1.tga	- Upper floor window
Window2.tga	- Upper floor Window
Window3.tga	- Upper floor Window
Window4.tga	- Upper floor window
ComBlank.tga	- Ground floor commercial blank
ResBlank.tga	- Ground floor residential blank
ComDoor.tga	- Ground floor commercial door
ResDoor.tga	- Ground floor residential door
ComWindow.tga	- Ground floor commercial window
ResWindow.tga	- Ground floor residential window
Ledge1.tga	- Ledge texture (MUST be 16x16x32bit uncompressed TGA)
Ledge2.tga	- Ledge texture (MUST be 16x16x32bit uncompressed TGA)


Note that the alpha channel is used to define which parts of the texture is lit up at night and environment mapped during the day. 
Opaque is defined as white (255) and fully transparent as black (0).
