# How can deduct the length of door opening from the room boundary?

**URL:** https://forum.dynamobim.com/t/how-can-deduct-the-length-of-door-opening-from-the-room-boundary/11324
**Category:** Revit
**Created:** [April 26, 2017, 8:47am UTC](https://forum.dynamobim.com/t/how-can-deduct-the-length-of-door-opening-from-the-room-boundary/11324 "2017-04-26T08:47:58Z")
**Posts on this page:** 1
**Showing post:** 5

<div class="post-metadata">

### Author: ![Mohammadz](https://sea2.discourse-cdn.com/flex022/user_avatar/forum.dynamobim.com/mohammadz/32/22398_2.png) [@Mohammadz](https://forum.dynamobim.com/u/Mohammadz)
#### Post date: [April 28, 2017, 1:26pm UTC](https://forum.dynamobim.com/t/how-can-deduct-the-length-of-door-opening-from-the-room-boundary/11324/5 "2017-04-28T13:26:55Z")

</div>

I’ve checked your script…the approach is valid but your are making it more complicated… i do not know whats your end goal in doing this but i assumed two things :

- if you are seeking only to get the perimeter of each room with the doors subtracted then you can do this like @rexfrancojesse proposed… but use the room boundary instead of `Get Host Element` because get host would only calculate the walls which host doors and ignore the others…  

- if you want to get these base lines as dynamo elements and use them for further development then you can do this 

i hope this helps

---

_[View the full topic](https://forum.dynamobim.com/t/how-can-deduct-the-length-of-door-opening-from-the-room-boundary/11324)._