So I’m working on a game that takes place outdoors in the suburbs, so I need lots of building exteriors. The game has a first person camera so I need the textures on the buildings to look good at close range. Whats the best method to accomplish this? is it better to Use one huge texture atlas or to break individual pieces down into different materials? I know separate materials cause more draw calls but at what point is that inevitable. I’ve added images of the building I am trying to texture below.
Use tiling textures as much as you can. You can use those tiled textures on many assets. Then if you want to make it to look a little different from others just blend other maps on it either in material editor or use vertex paint. 
When working on environments in general, you want to take advantage of tileable materials. This means you have for example, a general wood material that tiles in all directions, which you can place on any mesh that requires a wood material. You need to build yourself a set of tileable materials for what you need (i.e. wood, metal, concrete, etc.)
These tileable materials should have both macro normals and detail maps; the detail maps will make the material look good at close proximity to the camera as you require (very important for first person games).
For very large objects that require more texel resolution, you will simply tile the material more or less as needed. A technique that is popular these days at studios, is the use of wear/grime masks. these are used to break up the repetition usually found when using a lot of tileable materials. You can create masks like this easily with something like Substance Painter or Substance Designer (a tool that has become popular like wildfire within the AAA games industry). Also, since you’re creating an urban environment, I recommend using decals to break up the repetition of your tiling materials even further.
Good luck with your project, hope those tips help!
Hey, thanks for the advice Guys I really appreciate it. Do you know any tutorials online that go into this type of thing?
I’m working on an online workshop right now that will cover a ton of techniques on environment art, including texturing using tileable materials (with Substance Designer) for Unreal 4:
Also, depending on what you want to achieve, detail textures via detail normals for example can help quite a lot to make a texture look better even if it’s resolution isn’t that high.
Take a look at the documentation here: Adding Detail Textures | Unreal Engine Documentation
Have a look at https://www.allegorithmic.com/ they offer a large amount of tileable textures in they’re software packs “Substance Painter and Designer” and it makes texturing much more easy and fun.
You can also find a lot of tutorials on they’re youtube site!
I have a (probably silly) question regarding this topic:
How to use tiling textures? Do I need to remove UV map from my mesh to properly tile a texture over it?
… Or do I need to set up a World Aligned material?
… Or maybe is there some option to ignore UV layout and map a texture using e.g. box projection?
uvs dont have to be placed in teh 0-1 range… u can scale the uv x 100 if u want it to tile 100 times.
I know, I was thinking about some easy method like this, but it works only with BSP: http://waynelee3d.com/blog/2014/03/24/repeating-texture-alignment-unreal-engine-4/
… To ignore UV layout and just use box/planar mapping. It would be handy
Theres such thing as that too… you can use the material editor to do scaling of uvs… u can even use it to do automatic projection from all sides with no uvs if u wanted. I do that for some of my stuff to save on time for walls inbetween objects made with a simple plane.
That’s great, but could you please tell me where can I enable this automatic projection? I can’t find it…
Its not something you enable. Its a material you have to create…
After a little bit of digging… World Aligned material seems to do the job
Edit: The only problem is that texture is also rotated in world coords 
then use teh material to rotate the texture. or … rotate the texture.
yes. is it better to break individual pieces down into different materials in photoshop.
Since we cant scaling imported SBSAR, this is the best method, am I right? Is it 100% works well? even on mobile?
Alternatively you can also try EXTILE - a non repetitive tiling material made exactly for that:: EXTILE BASE Non-repetitive tiling material in Materials - UE Marketplace