Hi, Im sorry thanks again David, but Is it okay if you give me some pointers as im getting lost inbetween settings. I navigated to the costruction tab, and under construction sets, where Glass Doors is specified, I dragged in ASHRAE ExtWindow. Which I got from 'My Model'. I still get the same error?

instead of the previous error, I now get the following error for many surfaces:

* Severe * FenestrationSurface:Detailed="FACE 138", invalid blank Outside Boundary Condition Object * ~~~ * ...when Base surface uses "Surface" as Outside Boundary Condition Object, subsurfaces must also specify specific surfaces in the adjacent zone.

Did you edit boundary conditions in a text editor. The OpenStudio API if you remove one of two paired interior surfaces (such as interior windows) will switch the other matched surface outside boundary condition. You should no tend up with a surface that has an outside boundary condition of "Surface" but does not list the other surface in the outside boundary condition object field. You are not seeing that here. Try running surface matching measure on a copy of the model and see if that resolves it. Deleting interior sub-surfaces may also help you, OS intersection doesn't treat sub-surfaces.

Thanks again for the reply David. I actually read up on other issues similar to mine and you're right, I had to do some surface matching in sketchup, now the simulation works!

However, I was wondering how I can get the data output in excel spreadsheet formats? Is that only possible when running through energyplus on a windows machine? Also, Despite having heating and cooling schedules the simulation didnt pick up any heating or cooling loads which left the output with just lighting loads, the only energy calculated was for light schedules...

Please search for other topics on new questions and ask in a new thread if you can't find an answer.