The effect of the NYC Energy Conservation Code on roof projects
by Brian Sullivan
New York City Local Law 85 of 2009, which became effective July 1, 2010, established the New York City Energy Conservation Code (ECC) and ensured that the NYCECC was at least as stringent as the New York State ECC (2007 edition). When the 2010 NYSECC was released, Local Law 66 0f 2010 was enacted to incorporate the new state code and became effective December 28, 2010.
Amongst other mandates, the ECC requires that roof replacement projects on all multi-family and commercial buildings provide a new system with an R-value of 20, when all insulation is above the deck, or an R value of 38 when including insulation below the deck, in attic or ceiling spaces (i.e. batt insulation).
So how does this effect roof replacement projects?
Increased cost – The increased cost of the insulation should be considered when preparing a budget for a roof replacement project and certainly when reviewing a budget prepared prior to these requirements. However, many will argue this cost will be recouped by energy savings.
Roof system finished height – To establish an R-value of 20, a minimum of 3 inches of insulation is required. For most roof replacement projects, the existing roof system will have less than 3 inches of insulation, if any at all. The new roof system will have a finished surface higher than the previous. As a result, counter flashing\through-wall flashing may need to be removed and installed several inches above the current location. To further complicate the situation, existing parapet walls may have to be modified to ensure that they are 3’ 6” above the finished surface.
Interior conditioning – Due to the increased insulation at the roof level, modifications may be required to the heating and cooling systems particularly at the top floor of the building.
Are there any situations where this requirement does not apply?
Over unconditioned space – Since these requirements are for energy conservation purposes, the insulation is not required above unconditioned space (i.e. stairwell bulkheads). However, if the space is modified later to a conditioned space, the insulation would be required.
Reroof projects – If an overlay roof system is installed and the existing insulation or sheathing is not exposed, this requirement does not come in to play
Historic buildings – Registered historic buildings do not have to comply.
Now more than ever, proper planning is crucial for all roof replacement projects. During the planning stage, or at the latest during design, while the test cuts are being taken for asbestos sampling, the testing agency should record the composition and the thickness of the existing roof system. With this information the roof consultant can determine, in advance, what additional modifications may be required.
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