Pitched Roof help topic

Help on setting up the building geometry, including importing from BIM

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Pitched Roof help topic

Postby mwassmer » Mon May 21, 2018 8:45 pm

I have several questions and comments regarding the Pitched Roof help topic, which is under Building Models > Building Geometry > Working at Building Level - Blocks and Solar Collectors > Adding Blocks > Block Creation Options > Block Form:
  1. Does the geometry convention template choice affect how the roof zone perimeter is defined? This help topic seems targeted toward someone using an "internal" zone geometry convention.
  2. The text discusses automatic deflation of the adjacent lower block perimeter by the wall thickness so that "the resulting roof zone perimeter is then guaranteed to coincide with the lower adjacent zone perimeter(s) in the absence of a roof overhang". However, I don't believe this statement is true if the Exterior geometry convention template is used. Please clarify.
  3. One of the notes says, "The overhang created by the formation of the roof slabs (d in the above illustration) is only noticeable in the Edit and Visualisation views and will not be written to the IDF file i.e. unlike the roof zone overlap, it has no effect on the EnergyPlus shading calculations." Does this mean that the roof slab thickness X cosine of the slope does not contribute to exterior wall shading? If not, how do I ensure that it does contribute to the shading as it should?
  4. The word "overlap" is used in several places in the text and on the images. In this context, what is the difference between "overlap" and "overhang"?
  5. The text references "d in the illustration" twice, but I don't see "d" in any illustration.
  6. In the fifth illustration below "Automatic Pitched Roof Geometry," it appears that the red annotated arrows are defining the roof overlap to be equal to the exterior wall thickness. Perhaps I am misunderstanding this because I am having a very difficult time interpreting this illustration. The shading and linework conventions in this illustration are unusual.
Luis Sousa
Posts: 364
Location: Stroud

Re: Pitched Roof help topic

Postby Luis Sousa » Wed May 23, 2018 9:44 am


I believe that most of these questions are answered on the following help section:
https://designbuilder.co.uk/helpv5.4/#P ... iption.htm

But do let me know if you need any further help with this.


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