Now the Code has always allowed me to replace entry doors in kind without providing a new vestibule, but rip the entire storefront out and I can’t claim Exception 7 to 5.1.3 anymore (old exception f). We do so much storefront replacement at Metropolis the vestibules come up all the time on so many of our jobs, large and small.
Provided of course those buildings do actually comply once tested, otherwise there’s an awful lot of doors and windows to be replaced or air sealing work that will need redoing. This might work well for new buildings in NYC between 25,000 and 50,000 square feet as they’ll now have to test for air leakage anyway regardless of which Code, NYCECC or ASHRAE, the designers choose to follow. So if my entire building doesn’t leak more than 0.4 cfm/sf I don’t have to worry about making sure all my doors and windows are certified for air leakage. Also added to the air leakage requirements was a brand new exception, Exception 3, which states “products in buildings that comply with whole building air leakage rates of 0.4 cfm/sf” can be excepted from air leakage requirements. That said, metal coiling doors of all types serving semiheated spaces, like most vehicular occupancies, do not have to comply with air leakage requirements and are still excepted from 5.4.3.2. Said doors cannot leak more than 1.3 cubic feet of air per minute per square foot of area (cfm/sf) whereas the old section 5.4.3.2 did not have explicit provisions for vehicular access doors. Īir leakage provisions were updated under section 5.4.3.2 and now include provisions for “vehicular access doors”. In plain English that’s six inches of continuous polystyrene foam insulation on the roof deck now. This is all a good thing, as the new ASHRAE now requires roof decks to be insulated to R-30 just like the NYCECC. The old version of exception 6, exception e, said that if I so much as exposed the roof insulation I now have to make the roof comply with the Code and now I’m putting down 4” of polystyrene where once I may have had significantly less. On the other hand, Exception 6 to that same section was clarified to say that if I remove and replace a roof membrane, provided the roof is insulated in some form, I don’t have to re-roof the whole thing to comply with the new Code. Now “roof recovering” is exempt from Chapter 5 in its entirety, but be aware “roof recovering” isn’t a defined term so there’s still ambiguity about what forces compliance or not.
The old rules seemed to indicate that if I exposed the roof deck and/or insulation under my proposed scope of work, I’d pretty much have to update that roof area under my scope-of-work to comply with the roof insulation requirements established in Table 5.5-4. To begin they seem to have clarified (or muddied, depending how you look at it) the general exceptions regarding roof replacement / recovering. With this month’s newsletter we’ll be focusing on updates to the building envelope established in Chapter 5. Now that we’ve had a chance to get to know the new ASHRAE it is safe to say making the choice between the two is now more nuanced than ever. Before we go further I should clarify that the 90.1-2013 only applies to commercial buildings as defined by the Energy Code, which includes residential structures over three stories. In a previous newsletter I touched upon some of the changes between the IECC 2015 and the IECC 2012 and said I would follow up with a look at the new ASHRAE 90.1-2013 vs the old 90.1-2010 requirements. As usual the updated Code allows RAs and PEs a choice of actual Codes to follow – the IECC based NYCECC, or ASHRAE Standard 90.1 as modified by the NYCECC Appendix CA (not just Appendix A anymore). With the make or break date of October 3rd fast approaching for the new NYCECC we are going to continue looking at the differences between the new and old.