Solution for Environment Modeling

First of all, this article is the Bible for level design:

http://blog.joelburgess.com/2013/04/skyrims-modular-level-design-gdc-2013.html

After seeing a few tutorials, I came up with a way to make level design modular.

First, I figured out how to snap to grips and line up objects perfectly in Maya:

(keeping the pivot at a corner is a good thing.)

(I seamlessly snapped two plants to a cube by selecting constrain to grid and point in Maya)

Since it's a horror game and the levels only feels right by testing them and play with them, I created 9 20 by 20 Maya unites tiles for level designers to work with( two sizes of doors, a floor with a wall, a straight corner, a floor, a wall, a curved corner, a block, a staircases):

While level designer can play with those tile. I may start learning some more texturing techniques and start painting something.