Over the past year, NYC’s Green New Deal and its impact on the AEC industry has been a hot topic. Much of the discussed energy conservation measures have come to fruition in the NYC 2020 Energy Conservation Code, which went into effect on May 12, 2020.
One major advancement is in how issues of thermal bridging are addressed for new commercial buildings. Thermal bridging can be a major contributor to heat loss in buildings. A 2016 report from the Mayor’s Office of Sustainability shows that space heating is the largest contributor of energy use in NYC buildings at 42% of total energy use. For context, the next runner up is domestic hot water at 15%. By taking measures to curb thermal bridging, the goal is to reduce space heating energy use.
Thermal bridging is reduced by ensuring continuous insulation is maintained throughout the building envelope. The 2020 NYCECC specifically addresses instances where balconies and parapets penetrate insulation creating a thermal bridge. Two options are presented (specific to the Prescriptive and ASHRAE compliance paths of the NYCECC.) – either wrapping balconies and parapets in insulation or incorporating thermal breaks.
C402.2.9 Continuous insulation. In new construction, balconies and parapets that interrupt the building thermal envelope shall comply with one of the following:
1. Shall be insulated with continuous insulation having a minimum thermal resistance equivalent to the continuous insulation component required in the adjacent wall assembly as listed in Table C402.1.3. Where more than one wall assembly is interrupted by an adjacent balcony, the higher thermal resistance shall be followed.
2. Shall incorporate a minimum R-3 thermal break where the structural element penetrates the building envelope.
Structural thermal breaks maintain continuous insulation throughout the penetration while providing structural support through the insulation layer. Issues of heat loss, cold floors and condensation from thermal bridging can be avoided by using thermal breaks.
Compared to wrapping a balcony or parapet with insulation, structural thermal breaks are typically easier to install and achieve better thermal performance based on thermal modeling.
Looking for more details about the updates to the NYCECC pertaining to insulating balconies and parapets?
See our summary guide on 2020 NYC Code Requirements for Thermal Breaks.
To discuss structural thermal break solutions for your next project, give Schöck a call.