# Understanding making 2 story buildings

**URL:** <https://discourse.cataclysmdda.org/t/understanding-making-2-story-buildings/19467>\
**Category:** The Toolbox\
**Created:** [March 30, 2019, 6:27pm UTC](https://discourse.cataclysmdda.org/t/understanding-making-2-story-buildings/19467 "2019-03-30T18:27:37Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![dessometrics](https://avatars.discourse-cdn.com/v4/letter/d/f19dbf/32.png) [@dessometrics](https://discourse.cataclysmdda.org/u/dessometrics)\
**Post date:** [March 30, 2019, 6:27pm UTC](https://discourse.cataclysmdda.org/t/understanding-making-2-story-buildings/19467/1 "2019-03-30T18:27:38Z")

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So i have been reading up on all of the beginner Json info for buildings and I don’t really understand how you define something as the second floor of something. Can someone give me a bit more info or where I can go to find that info for myself.

also in the Overmap\_Terrain section not entirely grasping the use of the “extras” line.

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<div class="post-metadata">

**Author:** ![Axema](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.cataclysmdda.org/axema/32/10822_2.png) [@Axema](https://discourse.cataclysmdda.org/u/Axema)\
**Post date:** [March 30, 2019, 8:39pm UTC](https://discourse.cataclysmdda.org/t/understanding-making-2-story-buildings/19467/2 "2019-03-30T20:39:47Z")

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```
{
        "type" : "overmap_special",
        "id" : "Strange Cabin",
        "overmaps" : [
            { "point":[0,0,0], "overmap": "cabin_strange"},
            { "point":[0,0,-1], "overmap": "cabin_strange_b"}
        ],
        "locations" : ["forest"],
        "city_distance" : [20, -1],
        "city_sizes" : [0, 12],
        "occurrences" : [1, 1],
        "rotate" : false,
        "flags" : ["CLASSIC"]
    }

```

Defining a structure’s mapgen to the world can be seen at overmap\_specials.json, and you’ll have to pay attention on how coordinates work:

`[0,0,0]` is `x y z`, and `z` is the z-level, wherein a positive value means is a higher floor and vice versa…

```
{
    "type": "overmap_terrain",
    "id": "cabin_strange",
    "name": "forest",
    "sym": 70,
    "color": "green",
    "see_cost": 5,
    "extras": "field",
    "flags": ["NO_ROTATE"]
  }

```

I don’t know how `Extras` affect an overmap terrain, but it should have a value like `build` or `field` in it 😃