IRC R303.1 Glazing

Started by DaveBell, November 24, 2016, 10:48:38 PM

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IRC R303.1 says I need 8% glazing.  With a couple of exceptions.  Exception 3 says sunroom additions and patio covers shall be permitted for natural ventilation.  (Appendix H Patio Covers)  If I have a covered patio say 16x12, where my entry door is, I have an exception to the glazing requirement in R303.1? 


If the door meets the ventilation opening requirement it can open into an enclosed sunroom or patio that has fresh air just as if it were opening to the outside air. It doesn't negate the requirement, it means you can go through that florida room to get your light and air... you can call that room "outside". Read AH103.2 again with that thought. I ran into this a year or so ago in an older house that had a dining room with no opening to the outside. We did have a French door that opened onto an enclosed side porch full of windows. I asked the inspector about it and he opened the French door and a window, "you pass".  You can also get there with lights and a whole house fan. This one came out of tenements around the turn of the century with interior apartments that had no natural light or ventilation.. not healthy. Don't forget the egress requirements as well, section 310.


Thanks Don!!
The front door (w/ screen door) did meet the 4% ventilation requirement. 
The bedroom windows will also.  I can reduce the glazing requirement with lighting - saw that. 
I can now design to reasonable and secure.