if you need a unique texture on all faces, you will need to scale them down and/or break them up into more textures/materialsif a repeating texture is fine, take a look into "trimsheets" and tileable textures ( https://www.youtube.com/watch?v=uUJShalzWy8 quick google search, didnt check content)
if you are using trimsheets or tileable textures, it is possible, because your UV layout can be outside of the 0-1 grid.the textures get repeated outside the grid
We have great resources on texturing buildings herehttp://wiki.polycount.com/wiki/Modular_environments http://wiki.polycount.com/wiki/MultiTexture#Trim_Sheets