Model was originally designed for an animation and therefore polycount is reduced as possible (use your greebles to add more detail if required).
Design of the door is my own.
The 3 part-door/gate is rigged with "idiot safe" one control bone rig to control all three door/gate parts.
Render is with AO as there's no light in the file.
Layer 1 contains rigged door and wall tile (use array to expand)
Layer 2 contains complete door mesh with mirror modifier (useful if you make changes, rip door parts later apart)