Problem with collision detection PLEASE HELP ME!!

Hello folks,

Im almost giving up with this I cant figure out what more to do.
I did tried many combinations of scripts with no luck :frowning:

My problem is that Im having problem by destroying an auto generated building to have it replace with my custom mesh.

In Screenshot-1 you can see that the auto generated building has no name, is in a Building Layer and has an Mesh Collider on it.

On Screenshot-2 you can see that my custom mesh has also an auto generated name, a Box Collider and my ObjectCollisionDestroy c# script.

WHAT DO I NEED TO DO TO HAVE THIS WORKING??

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class ObjectCollisionDestroy : MonoBehaviour {

    //Detect collisions between the GameObjects with Colliders attached
    void OnCollisionEnter(Collision collision)
    {
        Debug.Log(collision.gameObject + " Touched a Building!");
        Destroy(collision.gameObject);

        //Check for a match with the specified name on any GameObject that collides with your GameObject
        /*
        if (collision.gameObject.name == "MyGameObjectName")
        {
            //If the GameObject's name matches the one you suggest, output this message in the console
            Debug.Log("Do something here");
        }
        */

        //Check for a match with the specific tag on any GameObject that collides with your GameObject
        /*
        if (collision.gameObject.tag == "POI")
        {
            //If the GameObject has the same tag as specified, output this message in the console
            Debug.Log("If the GameObject has the same tag as specified, output this message in the console");
        }
        */

        /*
        if (collision.gameObject.layer == LayerMask.NameToLayer("Buildings"))
        {
            Debug.Log("Touched a Building!");
            //Debug.Log(LayerMask.NameToLayer("Layer_Name"));
        }
        */
    }

    // Use this for initialization
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {

    }
}

[108084-screenshot-2.jpg|108084]@Dragate thanks for the quick reply and help.
I have added the rigidbody to my custom mesh prefab and its kinda works but now Im having another issue.

On screenshot-1 you can see I have the Box Collider at 5.2 and that it detects that its colliding with the building but it doesnt destroy it.
On screenshot-2 I have lowered the Box Collider to 5 so its exact on the grid and it just destroy everything.

Is there a way I can limit the destroy to just the building layer??