The number of energy conservation and renewable energy projects have increased dramatically in the last several years. Although well-intended, this type of work could have the potential to compromise the integrity and character-defining features of a historic property. It is important to have thorough planning, communication, and acknowledgment that as an owner/steward of a National Historic Landmark (NHL), the utmost concern is to identify/embrace treatment options that preserve the qualities for which the property was originally designated.
In 2010, the Secretary of the Interior’s Standards for the Treatment of Historic Properties with Guidelines for Preserving, Rehabilitating, Restoring, and Reconstructing Historic Buildings had not been updated to reflect rapidly changing technologies related to renewable energy and sustainability measures. The standards did provide advice regarding retrofitting and weatherization measures to increase energy efficiency, but had not acknowledged the more current “green” projects that have arisen recently. The Standards are responsible, common sense principles presented in non-technical language. They were developed to help protect our nation's irreplaceable cultural resources by promoting consistent preservation practices.
Of the four treatments identified in the Standards, “rehabilitation” is the most commonly
employed. It is defined as: the act or process of making possible a new or compatible use
for a property through repair, alterations, and additions while preserving those portions
or features which convey its historical, cultural, or architectural values. This treatment
assumes that at least some repair or alteration of the historic building or landscape is
required in order to provide for an efficient contemporary use. It is the most appropriate
treatment with regard to sustainability projects.
Recently, the Technical Preservation Services program of the National Park Service released
The Secretary of the Interior’s Standards for Rehabilitation & Illustrated Guidelines
on Sustainability for Rehabilitating Historic Buildings. As stated in this publication,
these are the first official set of guidelines on how to incorporate proposed work to
improve energy efficiency while preserving the critical historic character. The guidelines
begin with the concept that historic buildings are by their nature inherently sustainable
(i.e., “the greenest building is the one already built”), and this should be used to advantage
in any proposal to upgrade them. They offer specific guidance on “recommended” rehabilitation treatments and “not recommended” treatments (those that could negatively impact a building’s historic character).
The new Guidelines on Sustainability cover a range of energy efficiency measures:
weatherization and insulation; heating, ventilation, and air conditioning (HVAC); window
treatment; solar technology; wind power; green roofs and cool roofs; site features
and water efficiency. (Geothermal and hydroelectric energy measures are not discussed.)
Although guidelines for landscape sustainability are limited, they offer a sensible starting
point for consideration. These useful guidelines add to the previously established
preservation principles developed for consistency and are presented in a manner that
allows a fair degree of flexibility. They can be accessed at: http://www.nps.gov/history/
hps/tps/index.htm. As always, please consult individual State Historic Preservation Offices (SHPO) web sites for additional information on this issue.
Originally published in "Exceptional Places" Vol. 6, 2011, a newsletter of the Division of Cultural Resources, Midwest Region. Written by Geoffrey Burt.