Sustainability and the built environment is a hot topic. In the planning and preservation world, sustainability is often linked to conversations about climate change, energy-efficiency, increasing density when the population is growing, and how to preserve our heritage for future generations. Today, I’m going to very briefly touch upon energy usage.
The built environment uses up to 40% of the world’s energy. It is common knowledge that buildings use a lot of energy for heating, air condition, and electricity. Nowadays, we frequently see demolition of existing buildings to replace them with new, energy-efficient and LEED marketed buildings. However, reuse of existing buildings can often be more sustainable and energy-efficient than the most energy-efficient new building. While it takes a ton of energy to heat, cool, and light a building, which is referred to as a building’s operational energy, we often forget about a building’s embodied energy. Embodied energy is the energy buildings generate through their life cycle of production of materials, transportation, construction, demolition, and disposal.
The National Trust for Historic Preservation’s Preservation Green Lab published a report in 2011 that found that reusing buildings is the best solution for the environment, “For those concerned with climate change and other environmental impacts, reusing an existing building and upgrading it to maximum efficiency is almost always the best option regardless of building type and climate.” After performing a lifecycle analysis on different building typologies in a few different cities, the Preservation Green Lab found that even if a new building is 30% more energy-efficient than an existing building, it can still take 10 to 80 years for that new building to make up for the negative impacts of construction-related energy usage.
Source: Preservation Green Lab
While I am sharing just a very small piece of information on historic buildings and energy-efficiency, there is an enormous amount of research on this topic that you can explore. For starters, you can click here for the full Preservation Green Lab report and here for more information on sustainability and preservation. My point of this post is: for those not in the preservation world, it is important for you to think twice about demolition of any building.
Main photo: Pacific Branch Library, Boerum Hill, Brooklyn (I’m worried this library will be torn down (as many NYC libraries are on the chopping-block). It would be more sustainable to reuse this building for another purpose.)
 Avrami, Erica, “Making Historic Preservation Sustainable,” Journal of the American Planning Association (2016), p. 2.
 Fernandez-Solis, Lavy, and Culp, “Need for an embodied energy measurement protocol for buildings: A review paper,” p. 3732
 “The Greenest Building: Quantifying the Environmental Value of Building Reuse,” Preservation Green Lab: National Trust for Historic Preservation (2011), p. 4.