Sustainability > Windows

THE SECRETARY OF THE
INTERIOR’S STANDARDS FOR
REHABILITATION &

ILLUSTRATED
GUIDELINES ON
SUSTAINABILITY
FOR REHABILITATING
HISTORIC BUILDINGS

  • Corridor with windows glazed with obscure glass in the walls and the doors, and a person opening a door and another person opening a transom.
    Recommended The wall and door glazing ensures that the corridor receives natural daylight and the operable transom helps air to circulate in this historic office building.
  • Detail of the exterior of a stone house with storm windows and shutters.
    Recommended Historic exterior storm windows have been well maintained and continue to perform as intended.
  • Close-up view of exterior storm windows and shutters that are in good condition.
    Recommended Historic exterior storm windows have been well maintained and continue to perform as intended.
  • Frame house with exterior storm windows tilted open to allow ventilation.
    Recommended Historic exterior storm windows have been well maintained and continue to perform as intended.
  • Close-up view of a broken sash cord on a wood window.
    Not Recommended A broken sash cord can be repaired easily and does not justify replacement of the window.
  • Close-up of a mullion of an interior storm window and a window, showing that they match.
    Recommended These exterior storm windows match the pane configuration of the historic interior windows in a residence and in a multi-story hotel building.
  • Close-up of an interior storm window and a window, showing that they match.
    Recommended These exterior storm windows match the pane configuration of the historic interior windows in a residence and in a multi-story hotel building.
  • Close-up of an interior storm window placed within a window opening and matching the window in color.
    Recommended The new metal interior storm window was carefully matched to the exterior window as part of the rehabilitation of this historic armory building.
  • Red brick building with boarded-up windows and window openings that have been blocked down to accommodate smaller windows.
    Not Recommended Not only have incompatible windows that do not fit the size and shape of the historic window openings been installed, but the original openings have also been shortened to install through-the-wall HVAC units.
  • Exterior view of crooked exterior storm windows that do not fit the window opening.
    Not Recommended Ill-fitting exterior aluminum storm windows viewed from both inside and outside are clearly not energy efficient.
  • Interior view of crooked exterior storm windows that do not fit the window opening.
    Not Recommended Ill-fitting exterior aluminum storm windows viewed from both inside and outside are clearly not energy efficient.
  • Brick industrial building with steel multi-light windows undergoing repair.
    Recommended Original metal windows were appropriately repaired as part of the rehabilitation of this historic industrial building. Before rehabilitation.
  • Two men repairing steel multi-light windows on a brick industrial building.
    Recommended Original metal windows were appropriately repaired as part of the rehabilitation of this historic industrial building. During rehabilitation.
  • Two men repairing steel multi-light windows from the inside of a brick industrial building.
    Recommended Original metal windows were appropriately repaired as part of the rehabilitation of this historic industrial building. After rehabilitation.
  • Mill building with multi-light metal windows, red brick spandrel panels, and masonry framing elements.
    Recommended Original metal windows were retained and made operable during the rehabilitation of this historic mill complex. Installing patio slider doors as interior storm windows was a creative and successful solution to improve the energy efficiency of the existing windows.
  • Multi-light metal windows after repair on a masonry building.
    Recommended Original metal windows were retained and made operable during the rehabilitation of this historic mill complex. Installing patio slider doors as interior storm windows was a creative and successful solution to improve the energy efficiency of the existing windows.
  • Multi-light metal windows with sliding doors used as interior storm windows.
    Recommended Original metal windows were retained and made operable during the rehabilitation of this historic mill complex. Installing patio slider doors as interior storm windows was a creative and successful solution to improve the energy efficiency of the existing windows.
  • Detail of windows in a steel and glass curtain wall, with hand-written notes pointing out “Deteriorated support rails” and “Broken spandrel glass”; also with two different tints of glass.
    Recommended The original windows, which were deteriorated beyond repair, featured a dark tint. They were replaced with a slightly lighter-tinted glazing to improve daylighting in this mid-century modern office building.
  • Windows with tinted glass in a steel and glass curtain wall on a building.
    Recommended The original windows, which were deteriorated beyond repair, featured a dark tint. They were replaced with a slightly lighter-tinted glazing to improve daylighting in this mid-century modern office building.
  • House with brown shingle siding, a wrap-around porch, and awnings over the second floor windows.
    Recommended Traditional canvas awnings should be retained when they exist on historic buildings.
  • View from a room in an old hotel, looking from within the room through the door, which has a screen door and an open transom for ventilation.
    Recommended Transoms and screen doors are distinctive and practical features that provided cross ventilation in this historic hotel.
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Windows

Recommended
Not Recommended
Maintaining windows on a regular basis to ensure that they function properly and are completely operable.
Neglecting to maintain historic windows and allowing them to deteriorate beyond repair with the result that they must be replaced.
Retaining and repairing historic windows when deteriorated.
Removing repairable historic windows and replacing them with new windows for perceived improvement in energy performance.
Weather stripping and caulking historic windows, when appropriate, to make them weather tight.
Installing interior or exterior storm windows or panels that are compatible with existing historic windows.
Replacing repairable historic windows with new insulated windows.
Installing compatible and energy-efficient replacement windows that match the appearance, size, design, proportion and profile of the existing historic windows and that are also durable, repairable and recyclable, when existing windows are too deteriorated to repair.
Installing incompatible or inefficient replacement window units that are not durable, recyclable or repairable when existing windows are deteriorated beyond repair or missing.
Replacing missing windows with new, energy-efficient windows that are appropriate to the style of historic building and that are also durable, repairable and recyclable.
Retrofitting historic windows with high-performance glazing or clear film, when possible, and only if the historic character can be maintained.
Retrofitting historic steel windows and curtain-wall systems to improve thermal performance without compromising their character.
Installing clear, low-emissivity (low-e) glass or film without noticeable color in historically-clear windows to reduce solar heat gain.
Retrofitting historically-clear windows with tinted glass or reflective coatings that will negatively impact the historic character of the building.
Installing film in a slightly lighter shade of the same color tint when replacing glazing panels on historically-dark-tinted windows to improve daylighting.
Introducing clear glazing or a significantly lighter colored film or tint than the original when replacing historically-dark-tinted windows.
Maintaining existing, reinstalling or installing new, historically-appropriate shutters and awnings.
Removing historic shutters and awnings or installing inappropriate ones.
Repairing or reopening historically-operable interior transoms, when possible, to improve air flow and cross ventilation.
Covering or removing existing transoms.