Query
As per ECBC 2007, a building is ECBC compliant if the building meets the energy use as mentioned in the whole building simulation approach.
The guide does not emphasize on meeting the SHGC values in the simulation approach . Does this then allow us to bypass meeting the SHGC values mentioned in the perspective approach for a project registered under GRIHA v 3.1.
If not kindly provide suitable alternatives.
Solution
Although it is a prescriptive requirement in ECBC, meeting SHGC requirements is mandatory under GRIHA v.3.1. Please refer to the following previously answered query for windows exempted from SHGC compliance: https://grihaservice.zendesk.com/hc/en-us/articles/115003455425-Windows-of-which-areas-are-exempt-from-meeting-SHGC-requirements-
Suitable alternatives are listed as below:
All the fenestrations meet the SHGC requirement of ECBC-2007 / Weighted Façade average SHGC (for each orientation) meets SHGC requirements of ECBC-2007
OR;
Alternatively use Tables 9 & 10 of SP 41 to design the shading device for the windows.
OR;
Conduct solar path analysis for windows of AC as well as non-AC spaces, to ensure that the window is completely shaded for the duration between 10:00 am on 1st April to 15:00 on 30th September
OR;
Any combination of the above strategies on 100% of the fenestrations.