After exporting from Revit, and once viewing your model in the app 3D visualization page, you may find your geometry is not a 100% closed, air-tight model. Examples include gaps in the envelope, opened corners at wall joins, or windows offset from their host walls. The reason for these openings is due to how the plugin selects and exports mesh geometry from each of your building components. For walls, floors, and roofs the centerline plane is identified and data related to surface area and mesh coordinate points are export. For windows, the reference plane will be exported which is typically not in the same plane as the walls but offset to the innermost face. Since the thickness of the objects are not getting exported to the web app, some gaps might be created in the places where two walls join or in the window openings.

For energy simulation, covetool considers your geometry and all the spaces closed and the gaps visible in your model won't have any effect on the energy results. Factors like infiltration and related CFM values are entered separately on the baseline energy page, and not extracted from your geometries air-tightness. This allow for dirtier, less developed models from our user base to import their geometry.

For the 3D analysis including sDA and ASE, some daylight can enter the space through these gaps, which have a very insignificant effect on the overall daylight and glare results. If the gap is less than 12'', the impact of these gaps on the daylight and glare results would be less than 1%. You might see some light colors on the heat map but the percentages wouldn't change significantly. However, if the gaps are wider than 12'', you might take the following steps to fix the geometry issue.

Corner Walls Gap:

There are three different types of wall joins in Revit including:

  1. Butt Join ( the default join type)

  2. Miter Join

  3. Square off Join

When walls intersect, Revit creates a butt-join by default and cleans up the display in plan view, removing visible edges between the joined walls and their corresponding component layers.

In this case, a gap will be created when covetool plugin picks either the outer or centerline plane for each of the walls. To avoid this gap, you need to change the type of wall join from Butt to Miter.

To change the wall join, you can go to the " Modify " tab and under the " Geometry " section click on " wall joins " button. Select two walls you are considering to change their join type and select the " miter " option.

The structure of miter join removes the gap created by default join when using covetool plugin. You can remove the gaps that are wider than 12'' like this and re-export the geometry to the web app to proceed with 3D analyses.

Window Openings Gap:

If there is a gap between the windows and the wall, you can use the " flip " command and flip all your windows in Revit and then re-export the geometry to the web app. This will fix the gaps in the openings.

One last note :

As mentioned earlier, gaps less than 12'' wide don't significantly affect the sDA and ASE percentages. Although you may see some light spots on the heatmap, the results will be almost the same since when averaging the lux for all the grids, the difference will be less than 1%.

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