New Materials Old Houses; When, Where, What?
By: Ronald Wanamaker, Wanamaker Restoration
Recently Preservation Burlington along with many other professionals, city officials, and building owners has been discussing the issue of replacement materials on historic buildings. Because of the frequency of substitute materials being used to replace and mimic the historic features of buildings the Planning Commission, Development Review Board and City Council need to implement a standard to review such projects. It is the time to decide whether Burlington adopts a conservation ethic that supports and encourages sustainability and regard for our heritage or supports the continued development status quo with its disposable new vs. old, planned obsolescence mentality that fills our landfills.
It is irresponsible to continue to encourage citizens to replace functional, long lasting building components with untested or substandard materials. The loss of original, old growth wooden house parts is like clear cutting our old growth forests again. Many of the materials on our old homes are of irreplaceable quality. My own windows as an example are 139 years old. For less cost – including labor – than replacement windows of comparable design I have re-glazed, painted, replaced sash chain and installed new storm windows. I fully expect, with minor maintenance, to realize another 100 years for this investment. Had I chosen to replace I would realistically be replacing the replacement units within 25 years. Aside from the landfill issue or the economic realities, the energy output required to manufacture even one set of replacement windows is a real measurable impact on our planet. The State Historic Preservation Office puts it best:
Preservation is part of the Vermont ethic: you don’t throw something away if it is still useful. It is good common sense in the fullest sense of the Vermont tradition to conserve, use, and improve what you already have.
WHEN are substitute materials appropriate?
Replacement materials are an important and necessary part of every maintenance and repair cycle. Alternatively, substitute materials should never be considered on a building that contributes to Burlington’s historic fabric.
When a building component has failed, and the cause has been identified and addressed, the damaged material can and should be replaced with the same or similar materials. This type of repair is called “replacement in kind.” In the case of 80 year old siding for example, if water damage has been diagnosed as migrating moisture from an un-vented bathroom and a cycling vent has been installed, then wood siding of the same dimension and reveal can be installed and expected to last another 80 years.
Substitute materials are materials of a different property or composition than the original materials. Although there are situations when these untested and experimental materials may be warranted they should be installed in a very limited way and revisited periodically to access their viability.
When we look back at the substitute materials of the recent past asbestos, aluminum and then vinyl siding, we can all agree that their use on any historic building is ill-advised and has a negative impact on the value of the entire neighborhood. More recent comers in the substitute materials arena, fiber cement board siding for example are still untested and it remains to be seen whether they live up to their promise. Although, fiber cement board siding does have some potential as a useful substitute for wood siding in consistently moist environments, for instance where a sidewalk or an alleyway has been paved and run-off creates splash back that in turn “rots” wood siding. This application should only be considered in limited situations. According to the Environmental Protection Agency and Housing and Urban Development it is not recommended to replace siding or exterior building components purely to remediate lead paint hazards.
Reinforcing the conservation ethos; all maintenance and repair projects should seek to replace as little functioning original material as possible. It is important to stress “limited replacement” when discussing the appropriate actions to take when addressing damage due to external causes, this isn’t only economically prudent, but also the least destructive to both the environment as well as the heritage resources of our city.
It is important to note that 90% of the “restoration” that contractors do is replacing previously repaired materials!
WHERE they can be considered?
If serious consideration is given to each situation and underlying causes of deterioration have been addressed, than replacement may be necessary. Primary facades demand the most attention and should be treated with the most sensitivity. Secondary and rear facades allow for more latitude in both design and material choices. Although every building that is eligible for listing on the National Register or is a contributing building within an historic district should be treated with the utmost care as they all contribute to value of our community.
WHAT those materials may be?
We have agreed that aluminum and vinyl siding are inappropriate substitute materials when used on an historic home. Aluminum and vinyl are also inappropriate materials when considering replacement windows on historic buildings for many of the same reasons. When replacing damaged building components, whether siding, windows, doors or any other visible decorative element, they should be replaced with components that match the original in size, profile and material. For instance wood replaced with wood, slate with slate and so on. As mentioned earlier building materials like fiber cement siding may provide benefits in certain circumstances but should be considered only in limited applications. As for replacement windows, aluminum clad wood windows that provide the same glazing pattern i.e. Number of panes and muntins, are acceptable when an original window is damaged beyond repair. Aluminum as a cladding is recommended in this situation because new wood windows are not made of old growth lumber like the original windows and therefore do not have the “rot” resistance and will not stand up to the weather as well as the original windows that are being replaced. Again, the EPA and HUD both follow the recommendations of the Secretary of the Interior’s Standards for the Treatment of Historic Properties. I believe that Burlington would only benefit in adopting a similarly cautious approach in treating its own heritage resources.
In summation I encourage the City boards and the residents of Burlington to think of our built environment in the same way that we think of our natural environment. After all every piece of wood, glass, slate and iron came from our natural environment and it would be as thoughtless and inconsiderate to destroy and throw away those resources as it would to pollute our waterways and contaminate our atmosphere.