Upgrading Building Components

In addition to operational and mechanical upgrades, it can be possible to upgrade many building components in a manner that will not jeopardize the historic character of the building and can be accomplished at a reasonable cost. The goal of these upgrades is to improve the thermal performance of the building, resulting in even greater energy savings. Retrofit measures to historic buildings should be limited to those that achieve at least reasonable energy savings, at reasonable costs, with the least impact on the character of the building.

The following list includes the most common measures proposed to improve the thermal performance of an existing building; some measures are highly recommended for historic buildings, but others are less beneficial, and can even be harmful to a historic building.

Requires Minimal Alteration

• Reduce air leakage.
• Add attic insulation.
• Install storm windows.
• Insulate basements and crawlspaces.
• Seal and insulate ducts and pipes.
• Weather strip doors and add storm doors.
• Add awnings and shading devices where appropriate.

Requires More Alteration

• Add interior vestibules.
• Replace windows.
• Add insulation to wood-frame walls.
• Add insulation to masonry walls.
• Install cool roofs and green roofs.

The treatments listed fi rst have less potential to negatively impact the historic fabric of a building. They tend to be less intrusive, are often reversible, and offer the highest potential for energy savings. Undertaking any of the treatments in the second group, however, may pose technical problems and damage to historic building materials and architectural features. Their installation costs may also outweigh the anticipated energy savings and must be evaluated on a case-by-case basis with advice from professionals experienced in historic preservation and building performance.