# Another Vertex Mismatch Question

I'm getting a bunch of these errors and have read through this post and this post, but I'm not sure they apply or I'm misinterpreting them.

Here's the error:

```
** Severe ** RoofCeiling:Detailed="95599E35-C04C-423A-93DB-0577DF06C426-000078B4", Vertex size mismatch between base surface :95599E35-C04C-423A-93DB-0577DF06C426-000078B4 and outside boundary surface: 95599E35-C04C-423A-93DB-0577DF06C426-000078B4 REVERSED
** ~~~ ** The vertex sizes are 4 for base surface and 6 for outside boundary surface. Please check inputs.
```

But the vertex size is what's getting me; what does size mean exactly? At first I assumed quantity, but both of these surfaces have 8 vertices (not 4 or 6 like the error message says), and they look pretty identical to me.

```
BuildingSurface:Detailed,
95599e35-c04c-423a-93db-0577df06c426-000078b4, !- Name
Wall, !- Surface Type
Basic Wall, !- Construction Name
a064c6df6, !- Zone Name
Surface, !- Outside Boundary Condition
95599e35-c04c-423a-93db-0577df06c426-000078b4 Reversed, !- Outside Boundary Condition Object
NoSun, !- Sun Exposure
NoWind, !- Wind Exposure
, !- View Factor to Ground
, !- Number of Vertices
-80.2586, -58.022, 6.1, !- X,Y,Z 1 {m}
-80.2586, -58.022, 3.6, !- X,Y,Z 2 {m}
-80.5957, -58.9337, 3.6, !- X,Y,Z 3 {m}
-80.6471, -59.0725, 3.6, !- X,Y,Z 4 {m}
-80.6488, -59.0772, 3.6, !- X,Y,Z 5 {m}
-80.6488, -59.0772, 6.45, !- X,Y,Z 6 {m}
-80.5957, -58.9337, 6.45, !- X,Y,Z 7 {m}
-80.2586, -58.022, 6.45; !- X,Y,Z 8 {m}
BuildingSurface:Detailed,
95599e35-c04c-423a-93db-0577df06c426-000078b4 Reversed, !- Name
Wall, !- Surface Type
Basic Wall, !- Construction Name
a1875716c, !- Zone Name
Surface, !- Outside Boundary Condition
95599e35-c04c-423a-93db-0577df06c426-000078b4, !- Outside Boundary Condition Object
NoSun, !- Sun Exposure
NoWind, !- Wind Exposure
, !- View Factor to Ground
, !- Number of Vertices
-80.2586, -58.022, 6.45, !- X,Y,Z 1 {m}
-80.5957, -58.9337, 6.45, !- X,Y,Z 2 {m}
-80.6488, -59.0772, 6.45, !- X,Y,Z 3 {m}
-80.6488, -59.0772, 3.6, !- X,Y,Z 4 {m}
-80.6471, -59.0725, 3.6, !- X,Y,Z 5 {m}
-80.5957, -58.9337, 3.6, !- X,Y,Z 6 {m}
-80.2586, -58.022, 3.6, !- X,Y,Z 7 {m}
-80.2586, -58.022, 6.1; !- X,Y,Z 8 {m}
```

I am facing the same issue. Any updates about it?

Unfortunately not. I had to end up rebuilding part of this model in an overly simplified way

@bbrannon4, I was investigating several measures and codes and I solved the issue thanks to a BCL measure. It is the "Surface Matching Diagnostic". It simplifies the vertex numbers of non convex surfaces. P.S.:Keep in mind to run the measure every-time you upload the geometry, otherwise you will face the same issue.

Ah, good to know. I'm not typically in any OpenStudio environments, but that's a good tip for a cleanup step.