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Sustainable Historic Preservation

by the WBDG Historic Preservation Subcommittee

Last updated: 10-09-2014

Introduction

Historic buildings are inherently sustainable. Preservation maximizes the use of existing materials and infrastructure, reduces waste, and preserves the historic character of older towns and cities. The energy embedded in an existing building can be significant (PDF) of the embedded energy of maintenance and operations for the entire life of the building. Sustainability begins with preservation. A recent report The Greenest Building: Quantifying the Value of Building Reuse (2011) (PDF 10.5 MB) delved into the question of how green an existing building truly is. The Preservation Green Lab, a part of the National Trust for Historic Preservation, with the assistance of building constructors, sustainability consultants and life cycle analysts, established a set of case studies of recognizable building types; both renovated existing and new construction, in order to quantify the benefits of building reuse against that of new construction.

Recent advances in life cycle analysis (LCA) typically used in product design, are expanding into building/construction materials allowing the team to review new construction energy impacts. With some exception, comparing similar uses, types and locations, the existing buildings reduce climate impact over the newly built. Additionally, the findings suggest that even sustainably-constructed new built structures do not recoup energy outlays for approximately 30 years when measured against a renovated existing building. While more development is needed to mature the LCA approach, the Lab's conclusion was direct: reusing older buildings result in immediate and lasting environmental benefits.

Historic buildings were traditionally designed with many sustainable features that responded to climate and site. When effectively restored and reused, these features can bring about substantial energy savings. Taking into account historic buildings' original climatic adaptations, today's sustainable technology can supplement inherent sustainable features without compromising unique historic character.

LEED Silver Rated Balfour-Guthrie Building, Portland, Oregon

LEED® Silver Rated Balfour—Guthrie Building, Portland, Oregon

Preservation keeps our nation's history and culture alive and we learn much from the methods and practices of those who came before us. With our threatened environment, it is imperative that we make sustainable living a part of our lives. The public benefits of both preservation and sustainability are very clear and there is no reason why these goals cannot work together. Revising the current version of LEED® to better account for the social values and environmental benefits of preserving historic structures is a good start. The discussion, however, must continue to engage the preservation, sustainability, and construction communities to assure the best possible outcome.

 

Description

Preserving a building is often called the ultimate recycling project, yet preservationists commonly fight the stigma that historic buildings are inefficient and require daunting corrective measures to retrofit for energy saving devices and systems. Green and sustainable design has become an increasingly popular issue in both the preservation and new construction industries. Preservation and green goals overlap, and reconciling their differences is possible, provided that both sides strive to be as creative and flexible as possible.

The development of the International Green Construction Code (IgCC) by the International Code Council (ICC) is intended to become a new overlay standard to encourage the integration of sustainable design into new construction. The IgCC also provides provisions for existing buildings and existing building sites to incorporate sustainable design practices. This overlay code allows for local jurisdictions to tailor, through adopting electives, suitable options that address local and regional sustainability goals. Other sustainable design systems to consider include: Green Globes, though not a code, is capable of integrating sustainable design practices into existing buildings. Similarly, LEED O+M Existing Buildings, v4 provides a framework to coordinate sustainable design techniques into existing buildings, including historic architectural works.

The LEED® for Neighborhood Development Rating System (LEED®-ND) integrates the principles of smart growth, new urbanism, and green building into the first national system for smart, green, and healthy neighborhood design. LEED®-ND also addresses historic buildings.

The U.S. Green Building Council's LEED®O+M is a guideline for greening Existing Buildings. While this is a valuable checklist for maximizing the sustainable qualities of existing buildings in a real estate portfolio, it stops short of addressing historic buildings specifically. This page provides guidance for meeting LEED® and similar sustainability standards in historic building projects. Within the five LEED® categories, the following issues require special attention:

1) Sustainable Sites

Heat Island Reduction

Before the mid-20th century, most parking areas were pervious surfaces often surrounded by trees and covered with gravel to minimize mud problems. Specify low albedo porous paving, such as masonry pavers, reduce heat island effects and create the added benefit of controlling storm water runoff. Where treatment of run-off water is required provide an impervious barrier below a pervious surface to direct runoff to an oil-water separator and/or a treatment facility.

Heinz 57 Center, the former Gimbel's department store building green roofHeinz 57 Center aerial view of green roof

Heinz 57 Center, the former Gimbel's department store building; green roof.
(Photo courtesy of Pennsylvania State Historic Preservation Office)

2) Water Efficiency

Reducing water use can negatively impact historic plantings and landscape features. Preserve historic plantings and landscape features by balancing the water goals within the building and site.

Working Horse Farm, parts of which date from the 18th century, Fauquier County, VASurrounding landscaping of a Virginia Country estate

Working Horse Farm, parts of which date from the 18th century, Fauquier County, VA. Restricting water usage too greatly could irreparably damage the surrounding landscaping of this Virginia Country estate. The cultural landscape is an integral part of the historic setting, which must be respected.

Water Use Reduction

bio-swale, or depression in the earth, was created to redirect rainwater away from the storm sewer system at a former maternity hospital in Minneapolis

Former maternity hospital, Minneapolis, MN. This "bio-swale," or depression in the earth, was created to redirect rainwater away from the storm sewer system. Water entering this area is filtered and the natural process of absorption and evaporation begins. A "rain garden" is a more formal version of a bio-swale with the same desired effect. These sustainable features are appropriate provided they are sensitively sited; historic landscapes are not altered for their installation; there are no concerns regarding archeological resources; and they are designed in a manner consistent with the character of the site - for example, a formal rain garden planted with flowers would not generally be appropriate at an industrial site.
(Photo courtesy of the National Park Service)

rain barrel placed discreetly behind a historic house

This rain barrel is placed discreetly behind a historic house and has very limited visibility except from the rear of the property. (Photo courtesy of Audrey Tepper)

Historically, water conservation was a part of daily life. Cisterns collected rainwater and water was reused. Modern gray water recycling systems have evolved from traditional water conservation methods. Specify low flow toilets or consider options similar to historic technology.

"Cultural landscapes" often play central roles in the overall makeup or character of historic properties. They also need water to survive. Therefore, like historic structures, they must be cared for respected, even historic plantings that may not be native species. Efficient irrigation systems may be used to save water, and recycled 'grey' or rainwater may be captured for use in gardens and surrounding landscapes. But restricting water for irrigation to achieve the percentage savings required by LEED® may irreparably change the important relationship between a building and its surrounding landscape. Unfortunately, currently there are no provisions within LEED® for exempting cultural heritage areas from these calculations.

3) Energy and Atmosphere

Green buildings address energy and atmosphere issues through strategies that reduce the amount of energy required, and by using more benign or renewable forms of energy. Suggestions on approaches to the specific LEED credits within this category are discussed below.

Minimum Energy Performance

  • Working historic shutters can reduce heat gain significantly. Closing shutters in the morning and opening them in the late afternoon controls heat gain during warm months. In cold months, following the opposite pattern reduces heat loss. This is particularly effective when a building has significant thermal mass.
Highly visible solar panel on historic building (view 1)Highly visible solar panel on historic building (view 2)

Highly visible solar panels can have an adverse impact on both the historic building and the surrounding historic district. (Photos courtesy of the National Park Service)

  • Awnings, where historically appropriate, are efficient, and work with the seasonal path of the sun. Properly designed awnings can reduce heat gain by 65% and more.
  • In warm climates, make use of existing, deep overhangs to provide shade during the hottest part of the day while allowing sunlight to come in during cold months and cooler parts of the day. Overhangs also keep roof drainage away from building foundations, often negating the need for gutters and downspouts.
Firehouse; Pilot Point, Texas, 1906Firehouse; Pilot Point, Texas top row of window and roofline

Firehouse showing the use of awnings Pilot Point, Texas, 1906. Historic louvers should be retained for ventilation.

Adaptive use of a power plant in Richmond, VA retained the use of the monitor for sunlight and ventilation

Adaptive use of a power plant in Richmond, VA retained the use of the monitor for sunlight and ventilation.