Comment on the WBDG

We will send your comments, along with a link to this page, to the appropriate project members. Your information will not be kept in our records or used for any other purpose than to send the message. Fields marked with an * are required.

Name:*
Organization:*
Email:*
Message:*
Security Code:* 
(Please enter the code in  
the box provided. This
protects the form from
abuse.)  
Comment On This Page
Related Resource Pages
View Resource Page Index
This page contains document links to Construction Criteria Base
Home > Sustainable Historic Preservation

Sustainable Historic Preservation

by the WBDG Historic Preservation Subcommittee

Last updated: 07-23-2010

Within This Page

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 39% of the embedded energy of maintenance and operations for the entire life of the building. Sustainability begins with preservation.

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 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 recently adopted LEED-EB® as 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 runoff 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: 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

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

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 panel has 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.
  • Operable historic windows, louvers, and monitors substantially reduce demand for heating and cooling during temperate months. Educate occupants on effective use of windows. Open the top sash of a double hung window to allow warm air from the top of the room to escape. Open the bottom sash on the shade side of a room to pull in cool air while displacing warm air. It may be possible to maintain the operability of historic transoms over doors to provide cross ventilation in certain situations. However, most fire codes will not allow the use of operable transoms in certain types of facilities because it defeats fire walls and allows smoke/fire to easily migrate from space to space.
Fire House; Pilot Point, Texas, 1906Fire House; Pilot Point, Texas top row of window and roofline

Fire House; 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.

  • Preserve high ceilings to allow air to circulate and light to enter into a building.
  • Courtyards in hot climates traditionally provided shaded outdoor spaces and well-ventilated indoor spaces. Fountains and other water features reduce the energy required to cool these spaces and make courtyards more comfortable during the summer and temperate months. As water condenses, air is cooled. Located in a walled area, cool air is trapped low, providing relief and humidity in hot dry climates. Retain historic open courtyards and water features to achieve these benefits.
  • Historic masonry buildings are exceptionally durable and benefit from significant thermal mass. Thermal mass helps regulate the temperature inside by storing heat and cold within the mass of the wall.

Reuse of Historic Windows

LEED fails to acknowledge that historic windows are important features and that their energy efficiency can be upgraded. LEED encourages the use of highly energy efficient windows, which often requires the removal of historic windows that are potentially reusable. Moreover, original windows are character-defining features of historic buildings and their removal can significantly alter a structure's integrity, thus conflicting with preservation goals and the Secretary's Standards.

With proper maintenance, windows built from old growth wood can function indefinitely and their performance can be substantially bolstered by using storm windows, caulk, and weather-stripping. Studies have shown that these simple improvements can result in efficiency similar to that of new insulated glass windows. Modern windows also have a relatively short lifespan and can be difficult, if not impossible, to repair. Once modern windows fail, there are few ways they can be recycled, and they will likely end up in landfills. This begins an environmentally insensitive cycle of removal and replacement.

Early nineteenth century home where historic storm windows protect the original windowsClose up of early nineteenth century home where historic storm windows protect the original windows

Early nineteenth century home where historic storm windows protect the original windows, thereby retaining character and saving energy.
Photo Courtesy of Audrey Tepper.

Therefore, the most responsible approach is to retain historic windows that last and retrofit them with increased effectiveness rather than install new windows that, without exception, will fail and cannot be repaired. Regrettably, the replacement window industry is strong, and old windows are touted as poor performers, so the common practice of replacing windows in not likely to change much in the immediate future. To combat this, LEED should consider awarding points for the repair and continued use of old windows where significant improvements in energy efficiency are demonstrated, as well as where significant amounts of historic fabric are being retained and reused.

Specifically, many historic buildings featured hinged, wood storm windows that can be reused. Historic windows were constructed of dense, old growth wood. The life cycle of the majority of modern replacement windows is much shorter. Historic windows can be reused in an energy efficient manner. A traditional single-glazed, double hung window has an R-value of 1, compared to R3 for a new double-glazed, low-e, double hung window. If the historic wall assembly has an R-value in the teens, taking a window from R1 to R3 will not provide sufficient energy savings to offset the cost of replacement windows and associated waste. The primary cause of infiltration can be addressed with jamb insulation, weather stripping, and trim repair. For an extra layer between the occupant and the elements, a storm window can be mounted to the existing window—interior or exterior—with little change to the character of the original unit.

U.S. Custom House, Denver, Colorado (GSA)Skylight at Original Letter Handling Room: Byron White Courthouse; Denver, Colorado (GSA)

Left: U.S. Custom House, Denver, Colorado (GSA)
Right: Skylight at Original Letter Handling Room: Byron White Courthouse; Denver, Colorado (GSA)

4) Materials and Resources

Source Reduction and Waste Management

Consider use of appropriate salvage historic materials for restoration of lighting, hardware, and other specialty items. Most mid-sized cities have resources for salvaged building materials. Upgrade, rather than replace, historic fixtures.

Interior view of the Department of the Interior, Headquarters Building, Washington, DC. Department of the Interior, Headquarters Building, Washington, DC.

Department of the Interior, Headquarters Building, Washington, DC. Ongoing work to achieve a LEED Silver rating includes: utilization of energy efficient appliances, carpeting and furnishings with a high recycled content, efficient mechanical systems installed with minimal impact on the historic materials, energy saving lighting fixtures, maximizing interior daylight, and installing interior blast storm windows were added for security and energy efficiency. Historic windows were retained and their energy efficiency was bolstered by the addition of the blast windows.

Optimize Use of IAQ Compliant Products

Early paints and stains featured pigments made from natural plant materials and minerals. Use low volatile organic compounds (VOC) finishes.

Exterior and Interior Materials

While LEED does not yet focus on the value of durable materials in sustainable building, use of durable, renewable natural materials conserves resources in the long-term and is one of the significant sustainable aspects of historic buildings. Consider the embedded energy of existing materials in approaching rehabilitation of interior spaces.

Interior view of trusses on former manufacturing bulding conversionUsable skylights define the character of this industrial building and can be incorporated into the building's new use
Conversion of former maufacturing building where historic brick both defines the character of this industrial building and can be incorporated into the building's new use

Conversion of a former manufacturing building in Richmond, VA. Durability of Materials: few points are given for the durability and long life cycle of traditional building materials. Energy is also saved if it is not necessary to manufacture, transport, and install new materials. Durable trusses, historic brick, and useable skylights are all materials that both define the character of this industrial building and can be incorporated into the building's new use.

5) Indoor Environmental Quality

Outside Air Introduction and Exhaust Systems

Before the advent of mechanical air conditioning, most historic buildings featured natural ventilation, usually based on the chimney effect. Wherever practical, provide for natural ventilation to maximize efficient air flow, reduce occurrence of sick building syndrome, and increase occupant alertness.

Controllability of Systems: Lighting

Many early offices took advantage of a combination of natural light and task lighting. Retain large window openings and specify low height, directional lamps that illuminate work surfaces effectively. Consider installing sensors to maximize use of natural light by activating ambient electric light only as needed.

Daylighting and Views: Daylighting

Retain tall windows to allow natural light to penetrate a building. With the added benefit of higher ceilings, natural light can travel far into a space. Buildings in a "C" or "E" plan form were common and essentially functioned to facilitate natural light and ventilation. Additionally, skylights provide a flood of natural light, and were often used on the north face of a roof so not to produce glare.

Unsympathetic installation of skylights on a historic turretRetention of historic windows in this former power plant (converted to office space) in Richmond, VA

Left: Unsympathetic installation of skylights on a historic turret. Installation of skylights can enhance daylighting of a historic building, but only when these new features do not compromise the integrity of a historic building. In this case, the skylights are not sympathetic. Photo Courtesy of Audrey Tepper.
Right: Retention of historic windows in this former power plant (converted to office space) in Richmond, VA. Photo Courtesy National Park Service.

Back to top

Relevant Codes and Standards

Standards and Guidelines

Back to top

Additional Resources

WBDG

Design Objectives

Historic Preservation, Sustainable

Products and Systems

Federal Green Construction Guide for Specifiers

Government Agencies