Shading by adjacent structures not possible in LEED baseline and E+
In LEED Energy modelling for EA Credits, it is allowed (not compulsory) to include shading by adjacent structures. This can have an important effect on the results for the proposed building. However, in E+ there is no option to include only the shadowing by adjacent structures for the baseline case. If you remove all external shadowing with MinimalShadowing option, you don't account for adjacent structures. If you choose any other shadowing option, although you may remove all shadowing surfaces from the model, self-shading is always considered, which is not allowed by LEED.
Is there any solution I am not taking into account? The only option I see is to remove shading by adjacent structures, which can affect quite negatively the results from the proposed design.
Comments
So your problem is for the baseline then, where LEED says self-shading cannot be taken into account? Or do they forbid self-shading even for the proposed geometry?
Yes, the problem is for the baseline (but affects proposed, because if you cannot have it in baseline, you have to remove it also from proposed). They forbid self-shading only for baseline. It is said in 90.1 Appendix G, table 3.1#5: "The builiding shall be modeled so that it does not shade itself".
Very interesting! What do other engines do in this case?
eQuest has a keyword (that I have never seen anybody use) attached to the building surfaces (walls, roofs, etc)
SHADING-SURFACE: Accepts code-words YES and NO that tell the program that this exterior surface shades other surfaces. YES causes this EXTERIOR-WALL surface to be considered also as a BUILDING-SHADE surface with TRANSMITTANCE = 0(note: a roof in eQuest is an EXTERIOR-WALL too...)
I debated whether to add this as a comment here or on the answer - but the content is the same. With respect the eQuest keyword @Julien Marrec referenced above, I have used this on numerous models that have been submitted for LEED review. This agrees with the interpretation from Nick Caton listed by @macumber below, the baseline walls are not self-shading. Its also the case that all building shading devices in the Proposed model are not included in the Baseline model. I have never directly studied the impact this has on my results, but might be worth studying at some point.