# URBANopt and green roof

**URL:** <https://discourse.ladybug.tools/t/urbanopt-and-green-roof/17980>\
**Category:** dragonfly\
**Created:** [April 11, 2022, 2:16pm UTC](https://discourse.ladybug.tools/t/urbanopt-and-green-roof/17980 "2022-04-11T14:16:27Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Junoh](https://discourse.ladybug.tools/letter_avatar_proxy/v4/letter/j/df788c/32.png) [@Junoh](https://discourse.ladybug.tools/u/Junoh)\
**Post date:** [April 11, 2022, 2:16pm UTC](https://discourse.ladybug.tools/t/urbanopt-and-green-roof/17980/1 "2022-04-11T14:16:27Z")

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Hi I am Junoh and really enjoying using dragonfly and URBANopt.  
However, I figured out one bug(maybe?).  
When I apply HB vegetation roof material on the constructionset of DF model, it fails simulation. I attach the error message and gh file together. Please review kindly and let me know if it is impossible to model green roof or I should change the material type to just opaque material.

Thanks!!

[in.osw.log](https://discourse.ladybug.tools/uploads/short-url/u6Xi55jps2ljTTcdy9QWD8F8PAY.log) (13.4 KB)  
[from\_building\_footprints.gh](https://discourse.ladybug.tools/uploads/short-url/vmWTae2wNEuqSsppglUXRVwXhEE.gh) (127.2 KB)

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**Author:** ![chris](https://discourse.ladybug.tools/user_avatar/discourse.ladybug.tools/chris/32/10179_2.png) [@chris](https://discourse.ladybug.tools/u/chris)\
**Post date:** [April 15, 2022, 2:52am UTC](https://discourse.ladybug.tools/t/urbanopt-and-green-roof/17980/2 "2022-04-15T02:52:39Z")

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Hey @Junoh ,

The Vegetation material was not in the last stable release of the LBT plugin and it’s only in the latest development version. However, I don’t think that you have the latest version of the core libraries installed. Make sure that you run the [LB Versioner](https://docs.ladybug.tools/ladybug-primer/components/5_version/versioner) to ensure that you have the latest version installed.