Rehabilitation vs Demolition: Looking for the Cold, Hard (Green) Facts

Rehabilitation vs Demolition: Looking for the Cold, Hard (Green) Facts

Preservationists boldly claim ?the greenest building is the one that is already built.? While there are good qualitative arguments to that position, the field continues to search for proof in scientifically collected performance data that differentiates new construction from existing buildings.

Last week, we hosted the 1772 Foundation here at our headquarters on School Street. While the main focus of the day was to review the status of the foundation?s recent grant to HBI and the North Bennet Street School?s Handmade Houses program, MIT’s Sustainability Lab was also on hand to update the foundation and HBI on a student research project that models objective criteria for measuring the carbon use of new green construction and energy retrofits on older buildings.

The Sustainability Lab (or S-Lab), housed at MIT?s Sloan School of Business Management, was created to give students the opportunity to work through real-world problems and, with actual companies and organizations, study various aspects of creating a more sustainable world. The S-Lab students have worked with large companies, institutions, and non-profit organizations to reduce their environmental footprints and to create new tools to ensure responsible business practices. Last fall, with the support of the 1772 Foundation, HBI submitted a proposal to the MIT S-Lab to build a model that quantifies the carbon benefit of preservation. The goal of the project is to determine the carbon benefits of rehabilitating and preserving historic structures as opposed to tearing down subject properties and building a new building.

The S-Lab research will help the 1772 Foundation and Historic Boston analyze the carbon benefit byproduct of a building through the perspective of Life Cycle Analysis as opposed to the limited and static perspective of energy consumption at a given point in time. The MIT S-Lab’s model that will allow users to plug in certain criteria to better understand the embodied energy in a historic building and how that would compare to the demolition and construction of a new building in its place.

The model should eventually be able to quantify the volume of materials included in historic structures including wood, insulation, glass and metals as a basis for balanced comparison to more modern types of construction. Further, the model will also be designed to give an estimate of the amount of energy (and resulting carbon output) it takes to source, refine and transport the materials for a new replacement structure. While there is considerable work being undertaken by others on embodied energy, not all of it accounts for unique construction methods and materials found in many historic structures. The team expects to share the completed model with HBI at the end of this spring semester.

This Earth Day gives HBI pause to think concretely about the role of historic preservation in the fight to save our planet and reverse wasteful practices that put our world in danger. As we continue to reuse historic buildings and help make Boston’s neighborhood commercial districts (which are often dense, walk-able and located near public transit centers) more vibrant and viable, we believe HBI and its colleagues are supporting more sustainable living. We are hopeful that the model created by the MIT S-Lab students will be the framework within which HBI can gauge its investments going forward, further supporting the arguments for reusing our intrinsically ?green? built environment.

Check back here for more news about the S-Lab project and work that HBI is doing to ensure that the value of historic preservation is well understood in the green movement.

For more reading on the subject, check out the following websites of our partners, colleagues and fellow preservationists:
http://www.preservationnation.org/issues/sustainability/
http://www.preservationnation.org/issues/sustainability/green-lab/
http://www.preservationnation.org/magazine/2008/january-february/cautionary-tale.html
(featuring a quote from our own Henry Moss)
http://www.bostonpreservation.org/past/alliance_letter_summer08.html