Historic homes and buildings enhance our communities, provide us with a sense of place, and are nice to look at, but they are more than just pretty faces. Did you know that they can also play a role in the future sustainability of our environment? As Donovan Rypkema, principal of the real estate and economic development-consulting firm PlaceEconomics, has stated many times – “historic preservation is the ultimate in recycling.”
The construction of a new building requires the extraction of raw materials, manufacturing of those materials, transportation of the materials to the construction site, and actual construction. Every one of those actions uses additional energy and resources, such as gasoline, and may also involve using toxic construction materials like formaldehyde, silica, and PVCs. Additionally, construction debris – including the demolition of existing structures – accounts for approximately 25% of the volume in city landfills.
According to the National Trust for Historic Preservation, the majority of newly constructed building types will take 20-30 years to compensate for the initial carbon impacts from construction. This effect is not well mitigated even when the new construction is highly energy efficient, as it can take up to 80 years for an energy efficient new construction to overcome the environmental impact created by its construction (1). Many new buildings are not meant to last more than 50-65 years, and are made with materials that are inferior to the old growth, high quality wood found in most historic structures. Old growth wood is no longer widely available and, when found, is usually more expensive than typical building materials.
What about the windows??
Preservationists are often fighting an uphill battle when advocating for the preservation of original wood windows thanks to aggressive sales tactics and false information provided by window manufacturers. What many window salesmen will not tell their customers is that most homes only lose 10% of the energy through the windows (2). It will take decades to recoup the cost of replacing the windows via energy savings, and by then the windows normally require replacement again, restarting the cycle. Retrofitting historic wood windows instead of tossing them in the trash offers a higher return on investment and energy savings close to that of new, high performance windows (3) (4).
Fiber cement siding (such as Hardieboard or Hardieplank) is a very popular siding material that was introduced in the 1990s. It is made of a composite of cement and wood fibers. Other engineered siding materials (such as LP SmartSide), include composites of resin and wood strands. In some cases, these materials were placed on historic structures prior to the neighborhood obtaining Landmark status, or may have been allowed on the bottom two laps of a structure. Homeowners tend to ask for replacement of these materials at the same rate as our homeowners with traditional wood siding. Synthetic siding materials warp, degrade, and crack just like any other building material, particularly with improper installation which is a common problem with these products. In the majority of cases we see, only around 10-20% of wood siding requires replacement when the building has been painted and properly maintained. This is far less expensive than wholesale siding replacement with a synthetic product, and retention of salvageable wood siding keeps these materials from being disposed of unnecessarily.
It is clear that the reuse of historic structures and their materials saves waste from going into the landfill and reduces the demand for new materials while playing a significant role in our future sustainability. A growing body of research is demonstrating that an historic structure that is properly renovated and weatherized can rival the energy efficiency of new buildings (2) while creating 50% more jobs than new construction (1).
As Carl Elefante so succinctly stated – “the greenest building is the one that is already built!”
(1) The Greenest Building: Quantifying the Environmental Value of Building Reuse – National Trust for Historic Preservation
(2) Improving Energy Efficiency in Historic Buildings – National Park Service Preservation Brief #3
(3) Saving Windows, Saving Money: Evaluating the Energy Performance of Window Retrofit and Replacement – National Trust for Historic Preservation
(4) Don’t Buy Replacement Windows for Your Old House – Forbes
Research and Policy Lab – National Trust for Historic Preservation
Smart Growth and Preservation of Existing and Historic Buildings – Environmental Protection Agency
Sustainability and Historic Preservation – Washington State Department of Archaeology and historic Preservation
Repair of Historic Wooden Windows – National Park Service Preservation Brief #9
Research & Analysis – PlaceEconomics