Comcheck in TX

[Noob]

Hi Folks,
I have no experience with Comcheck, and I'm newly working in TX. I've always gone the prescriptive route, look up my R-values in the ASHRAE and meet them.
So, why then would I go through the tedious mess of comcheck if I can avoid it? Is there any real benefit? Am I missing some downside to the prescriptive approach?

This building I'm working on has a substantial amount of window area - so I'm thinking that Comcheck would actually perhaps not let me do this, whereas prescriptive path might - it looks like ASHRAE 90.1, 2013 does not care about fenestration orientation and only sets the max window area at 40% of gross wall area? Whereas I have to feed comcheck window areas, U factor, SGHC, orientation, projection factors, etc. etc.

I'm noticing Houston requires Comcheck, are other TX municipalities starting to require it?

I appreciate your feedback!

 

[Jay Smith]

The trade offs you get for projection factor, orientation and glass area are why I have typically used Com Check if the jurisdiction accepts it. I’ve had mixed use projects pass Com Check with retail storefront glass that has higher SHGC than the prescriptive requirements, just as one example.

 

[Noob]

The trade offs you get for projection factor, orientation and glass area are why I have typically used Com Check if the jurisdiction accepts it. I’ve had mixed use projects pass Com Check with retail storefront glass that has higher SHGC than the prescriptive requirements, just as one example.

I buy that - except the later versions of IECC appear to prescribe glass SGHC values (comcheck won't let you enter the SGHC if it doesn't meet the table in IECC).