Simple vegetation maps and models for architecture
The benefits of using low poly assets for architectural visualization are directly related to projects aimed at real-time 3D. In these days where people are not satisfied anymore with static images and non-interactive multimedia, we must change the way architectural visualization is born.
And to change that you probably will invest on real-time visualization using a game engine, such as the BGE or the Unreal Engine. Maybe you want to go for a full web solution with Blend4Web. No matter the technology, at some point you will need proper assets for real-time 3D.
Have you ever tried to add realistic vegetation to a project and export that to the Blender Game Engine? WebGL? If you did that, you might realize that your application performance will depend on the number of polygons, textures, effects in combination with the hardware.
The same vegetation you use for a render in Cycles, probably won't work well on real-time 3d projects. A common trick on such projects is to use only simple maps of vegetation applied to polygon planes. If you don't have such textures, I found a pack of simple maps that might be useful for architecture.
An artist named Nobiax did post a collection of simple maps for game projects. But, since all the maps are about vegetation we can certainly use it for architecture.
By following this link, you will visit the artist's page at Deviantart, and find the proper download link. Inside the file, you will get all the maps along OBJ and FBX files with the models. The textures are available as a diffuse map and also with full transparency (alpha).