• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

Commercial Vestibules

north star

Sawhorse
Joined
Oct 19, 2009
Messages
4,596
> > > &

I have a project where a bldg. owner wants to construct a small
vestibule at the front entrance to his bldg...….The plan is to
install a small store-front type assembly with a new Double Door
Assembly installed...…..The applicable Code is the `18 IECC.
The area is a Zone 3, Warm & Moist application.

I want to meet the glazing safety requirements and the Solar
Heat Gain Coefficient ( SHGC ) and the Winter U Factor
requirements for this project.


I am having difficulty in determining the min. requirements in
the IECC.


Any assistance will be GREATLY appreciated !

& < < <
 
Glazing safety requirements in addition to the energy code ? We haven't adopted the 2018, so I differ to the 15. What type of door swing type or non ? if swinging U factor is 0.61. If you have nothing, then the defaults would be in C303.1.3 tables 2 & 3. Also the prescriptive requirements shall comply with C402.4 of which appears to be 0.77 for entrance doors and orientation is below depending on projection factor. Can't say about the 2018 haven't been there yet.
 
I wouldn't split hairs on the IECC requirements as any improvements would be an improvement to the existing. My concern would be with the accessibility requirements; maneuvering clearances, "level" landings at the doors, etc. Just my thoughts.
 
IECC is easy. Table C402.4 requires a U-factor of 0.46 for fixed glazing (the storefront part) and a U-factor of 0.77 for the entrances.

For SHGC, it kind of depends if this is installed with an overhang or not and its orientation. The maximum for north-facing glass with little to no overhang or shade wall protection (projection factor, or PF) is 0.33. for south, east, or west orientations, the maximum SHGC is 0.25. With a PF of 0.5 or greater, then the SHGC can be as high as 0.40 regardless of orientation.

For glazing in the doors, Category II (16 CFR Part 1201) is required. For all other glazing, it sounds like Category II or Category A (ANSI Z97.1) is required unless one of the exceptions apply.
 
& ~ & ~ &

O.K., ...much thanks for the replies !

1st, ...both doors in the Double Door Assembly will swing

outward towards the exterior.

2nd, ...there will not be any Overhang....The doors when

installed will face due East......**RLGA**, ...what is PF ? :confused:


3rd,**khsmith55**, thanks for the reminder about the
Accessibility reqs…...There will be a level landing outside of
this planned door location.........The maneuvering clearances
are being reviewed.

& ~ & ~ &


 
If you don't have an overhang, then your PF is 0.

PF is for projection factor, based on the ratio A/B, where A is the distance of the overhang measured horizontally from the face of the glazing, and B is the distance to the bottom edge of glazing measured vertically from the underside of the overhang.

EDIT: I previously stated PF is for "project factor"--I inadvertently left off the "ion" for "projection."
 
Last edited:
Top