Sustainability in Historic Building Renovation

A major focus on sustainable construction and green building ratings systems in LEED is the section of new construction and major renovation.  There are many innovative methods of construction and working systems that are improving our new infrastructure to a great degree.  From the classroom to major published articles and national conventions, it seems that the department of new construction and major renovation takes the majority rule.  This is important as large new projects are where we can incorporate the leading green technology, but there are several millions of old buildings that are large violators of sustainability.  The focus of this post will be on historic building renovation, since they were built before today's high performance standards and contain antique operating systems.  Therefore, these buildings are perfect candidates for sustainable construction updates, but also need to be done in a way where their historic preservation and value is retained.  One example is of the Spigner House Renovation at the University of South Carolina, which was originally built in 1915.  Pictured below, this campus building earned a LEED Gold Certification from the Commercial Interiors Rating System

The USGBC has another green rating system in place where theses projects would fall underneath called LEED for Existing Buildings.  The building must be at least two years old and the credits listed promote using performance records, testing and analysis, and resource tracking.  The Existing Building category certification ensures the building is meeting the intended potential with high performance over time.  This category was developed in 2004 after a rating system was put together by a qualified committee and tested on 100 buildings before being placed as a LEED rating system.  The key component in acquiring initial certification is that three months of operational data must be collected and recorded.

Historical buildings have organizations for official registration and up-keeping.  According to the Environmental Building News article, Historic Preservation and Green Building: A Lasting Relationship, the National Park Service (NPS) oversees the National Register of Historic Places (NR).  A building must be over 50 years old and must have been used for a historical event/person, or contains significant craftsmanship, architectural, or design details.  There are over 80,000 listings in the NR, and with some containing multiple buildings it totals to over 1.3 million buildings!

Owners of a NR property who follow rehabilitation standards and application process are eligible for a 20% federal tax credit of the construction cost according to the Federal Historic Preservation Tax Credit.  The IRS requirements are that the construction cost must exceed the buildings cost basis and that it must be income-producing.  So this tax credit will only apply to substantial renovations, but many projects are still done every year.  On average 1,200 historic projects are done and around $2.8 billion is produced in private-sector investments.  The Secretary's Standards are the leaders as they have been in place since 1977 and help determine the appropriateness of historic property proposed work.  These four categories of rehabilitation, preservation, restoration, and reconstruction determine if a project is eligible for the 20% federal tax credit.  In summary, these standards either recommend or do not recommend certain material and system selection for projects.  The key concept is to always respect historical appearance and character defining features in improving the building.

For anybody learning about what to generally do with key components of a historical building project, the feature Sidebar: Considerations for Green Building and Historic Renovation does a nice job with a clear breakdown.  The building attributes of a historic building that already in place for positive sustainability are the natural daylighting from large windows, natural ventilation from older operable windows, material salvation to sell or donate, local sources and tradesman for careful repairs, and the existing "passive survivability" that already exists for site sensibility and livable conditions under loss of electricity.  Under most projects, the windows and operable windows will be brought back from their sealed or ineffective condition.  Using these base components effectively while preserving the building integrity will help form a foundation for the rest of the project.

In October of 2006, many organizations came together at the Greening of Historic Properties National Summit and collaborated on the issue of advancing sustainable construction in historic buildings.  A LEED for Historic Properties rating system has been discussed, but we will have to wait to see further implementation to help improve specifics and awareness for this sector of sustainable construction.