Track 1: Effects of Climate Change in Warm Weather Coastal Regions
In the race to meet Paris Agreement greenhouse gas emissions targets, which requires the built environment to be net zero carbon by 2050, existing buildings are frequently seen as a liability rather than an asset. At one end of the spectrum, they are left with poor energy performance through exemptions to building codes; at the other end, they are stripped of substantial historic value in the service of deep energy retrofits. Through the use of life cycle assessment, energy modeling, and best practices of preservation, conservation professionals can responsibly steward our built heritage while leveraging existing building fabric as a key part of meeting carbon reduction goals. This talk will illustrate an effective decision-making process that uses life cycle assessment to weigh considerations of embodied carbon emissions, operational energy upgrades, and impacts to historic or existing building fabric.
The historic built environment is a critical component to meeting net zero carbon goals because of the avoided impacts associated with building reuse and opportunities for dramatic reductions in operational energy. Additionally, crediting existing buildings with the avoided impacts of reusing existing materials frequently aligns with conservation goals of retaining historic fabric. Take, for example, the treatment of existing windows. Depending on the material, age, and condition of the windows, options for treatment may range from restoration plus the installation of a storm unit to reglazing of the existing frame with insulated glass units to wholesale replacement. Each of these options has a significant impact to the historic character of the building, as well as an embodied carbon price associated with the materials involved, and each will contribute to a certain reduction in operational energy use. Through life cycle assessment and energy modeling, one can determine how many years of operation are required to offset the embodied carbon of the treatment. It is then a matter of professional judgement to balance the carbon implications with responsible treatment of the historic fabric. This approach will be illustrated by case studies renovation projects where significant energy efficiency goals were balanced with preservation priorities.
Tackling climate change at a global level requires careful work at the scale of a single historic window - cultural heritage can and must play a key role in global carbon mitigation. In addition to their historic value, existing buildings offer tremendous environmental value through embodied carbon and inherent durability and resilience; however, building reuse must be paired with energy upgrades to fully leverage the historic built environment in combatting climate change. This talk will rethink our approach to construction and heritage conservation to enable the transformation of historic buildings to meet our climate goals.