how to get y position of an object

im working on a building system and need to get the y pos of the floor object that im “snapping on to”

heres my code any help is appreciated.

the parts with case “(collider name)” is what i need help with.

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

public class CardboardFloorCollider : MonoBehaviour {

    CardBoardFloor CardBoardFloorScript;

    Vector3 SizeOfCardBoardFloor;

	// Use this for initialization
	void Start () {

        CardBoardFloorScript = transform.parent.parent.GetComponent<CardBoardFloor>();
        SizeOfCardBoardFloor = transform.parent.parent.GetComponent<Collider>().bounds.size;


    }

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

    }
		//Snapping abillity
    void OnTriggerEnter(Collider other){
        if (BuildingManager.IsBuilding && other.tag == "CardBoardFloor" && CardBoardFloorScript.IsPlaced && !other.GetComponent<CardBoardFloor>().IsSnapped) {
            other.GetComponent<CardBoardFloor>().IsSnapped = true;

            float SizeX = SizeOfCardBoardFloor.x;
            float SizeZ = SizeOfCardBoardFloor.z;

            switch(this.transform.tag)
            {
                case "WestCollider":
                    other.transform.position = new Vector3(transform.parent.parent.position.x - SizeX, ?, transform.parent.position.z);
                    break;
                case "EastCollider":
                    other.transform.position = new Vector3(transform.parent.parent.position.x + SizeX, ?, transform.parent.position.z);
                    break;
                case "NorthCollider":
                    other.transform.position = new Vector3(transform.parent.parent.position.x, ?, transform.parent.position.z + SizeZ);
                    break;
                case "SouthCollider":
                    other.transform.position = new Vector3(transform.parent.parent.position.x, ?, transform.parent.position.z - SizeZ);
                    break;

            }
        }
    }
}

If i’m not wrong you’re trying to get y of “CardBoardFloor”.
And i see you were get SizeOfCardBoardFloor, and the y position, is transform.parent.parent.GetComponent().bounds.center.y;