Rochester is already one of the nation’s greenest cities, although we may not realize how or why. Older cities like ours have already expended the resources, both monetary and natural, to construct infrastructure like buildings, roadways, and utilities. Newer cities are still making these investments, which continue to grow in cost and environmental impact. If we consider our existing infrastructure similar to oil reserves, as resources we can tap for our development, we should be able to find a competitive edge over those expanding places.
Those of us working in historic preservation have understood this for decades. To us, there is no greener building than one already built. Regardless of how much “green” technology a new building incorporates, enormous amounts of energy, water and materials are used in its construction, and tons of pollutants are emitted into the environment. With an existing building, those expenditures and emissions have already occurred.
In our consumer economy we have an inane need to buy things. Couple this compulsion with the belief that there is a technological fix for every problem, and we relentlessly dump anything old for something new and, now, for something “green”. This new-is-better mentality pervades the construction industry, just like it does every other sector of the economy. In this era of sudden environmental awareness, people now believe that new technology will make buildings more “green”, and thus lessen environmental harm. Unfortunately, building green still means building, and we don’t know how to do that in a way that is environmentally benign. Until, and if, we learn how, the modus operandi is to tack some new gizmo onto the same sorry heaps we’ve been constructing for decades.
Mike Jackson, FAIA, chief architect of the Illinois Historic Preservation Agency, calculates that a new building can indeed recoup the energy expended to demolish an existing building and replace it with an equivalent energy-efficient building. It will just take 65 years. And that’s only the energy part.[1]
The Advisory Council on Historic Preservation, an independent federal agency, commissioned a study way back in 1979 to determine the amount of energy “embodied” in buildings, and found many surprises.[2] Some samples of its findings:
- Eight bricks embody the energy equivalent of a gallon of gasoline.
- The shell of a simple, 2-story brick carriage house embodies the energy equivalent of 8000 gallons of gasoline.
- Rehabilitating an historic arcade building used one-fifth the energy required to build a similar new building, saving the equivalent of 700,000 gallons of gasoline.
The Advisory Council also reported the average embodied energy for various building types, in terms of gallons of gasoline per square foot of floor area. Again, these data were gathered nearly 30 years ago, before many of our building materials, including steel, were originating overseas.
- Single-family house 4.7
- Retail store 8.2
- Industrial building 8.4
- School 12
- Dormitory 12.4
- Office building 14.3
- Hospital 15
From these numbers, one can readily figure that constructing the ubiquitous 14,000SF free-standing pharmacy building will take roughly 115,000 gallons of gasoline. In a car getting 30 miles per gallon, that’s enough to drive around the globe 138 times. Even a simple ranch-style house equates to 10 circumnavigations.
The following chart of the energy embodied in materials shows why historic buildings were much less energy intensive to build than new ones. [The numbers have no units of measure: their energy values were converted to multiples of the lowest value, that of locally gathered fieldstone. Thus, the manufacture, transport and installation of fiberglass insulation consume 38 times the amount used by fieldstone (so much for saving energy by insulating your home!).]
| locally gathered stone | 1 |
| concrete | 1.65 |
| lumber | 3.2 |
| brick | 3.2 |
| gypsum board | 7.7 |
| plywood | 13.2 |
| glass | 20.1 |
| fiberglass insulation | 38.3 |
| steel | 40.5 |
| PVC | 88.6 |
| aluminum | 287 |
By the way, we’ve had these numbers for 30 years and have done nothing with them.
Energy use is only part of the equation. Other environmental impacts of buildings and materials include emissions of gases like carbon dioxide, methane and chlorofluorocarbons that affect global climate; disposal of chemicals such as phosphates and ammonia that impair water quality; and enormous consumption of resources such as water and minerals. Today, many of these impacts can be modeled through life-cycle analysis software (there is, indeed, good, new technology), which shows that existing buildings are much better for environmental quality than new ones.[3]
Applying these measures beyond buildings to the larger construction sector of roadways, sewers, water treatment plants, airports, etc. shows the enormity of our challenges and of our opportunities. Rochesterians spend huge sums to construct and maintain public infrastructure that supports private development which often duplicates existing, sometimes historically significant, development. We then spend ever increasing sums on transporting ourselves between these new developments, and we spend more to demolish buildings people no longer occupy. And then we spend enormous sums on the externalities of these expenditures, such as environmental clean up and the protection of oil supplies. If just a fraction of a percent of this spending was redirected toward maintaining our existing infrastructure, we’d save money, energy and environmental damage.
States such as Michigan, Massachusetts and New Jersey have “fix it first” programs, where public funds are spent on repairing bridges, roadways, sewers and other public infrastructure before being spent on new construction. These states have documented the cost benefits of this approach, and are finding a competitive edge against states focused only on new construction. We in the Rochester area can find that same competitive edge over spendthrift regions, especially over those places where nearly everything is new.
In New York State, we already have a regulatory tool to promote reuse over new construction, if we are bold enough to broaden its application. The State Environmental Quality Review Act (SEQRA) requires that we identify any potential impacts of construction on the environment. As it is applied today, SEQRA assesses mostly short term impacts of construction, and certainly never asks what will eventually become of a building. But a SEQRA review could easily include an environmental assessment of the life cycles of building materials.
Among the resources SEQRA addresses are historic resources. Our region is replete with vast numbers of historic buildings, structures and landscapes, far more than most of our competing regions. Embodied in these are the natural resources that we now strive to protect. They also tend to be clustered together and are often along scenic waterways, on hillsides, or surrounded by fertile land. Yet we largely fail to account for their unique character or environmental benefits when we assess their value.
One oft-made argument is that older buildings are less energy efficient than new ones. But buildings constructed before the total reliance on machine-based climate control and electric lighting used various methods to passively gather and enhance daylight, solar heat, and cooling breezes. Contrary to some beliefs, we have learned that these older buildings can be as energy efficient as new buildings.
Architect Carl Elefante, FAIA, argues that “we cannot
build our way to sustainability; we must conserve our way to it”.[4] I agree.
[1] Mike Jackson, “Embodied Energy: Balancing the Eco Equation” Presented October 5, 2007, accessed online.
[2] Assessing the Energy Conservation Benefits of Historic Preservation, Advisory Council on Historic Preservation, January 1979. Simplistically stated, energy “embodied” in a material is that which is consumed over the life of the material. In the building industry, it includes all the energy inputs along the chain, beginning with harvesting or extracting raw materials from the earth, to processing them into useful substances, to forming those substances into building components, to shipping those components to a construction site, and then lifting them into place. An extension of this chain would include the energy needed to repair, remove, recycle or dispose of the components. An ultimate calculation would include the energy consumed by workers in the supply chain, notably that which is used for personal transportation.
[3] U.S. Environmental Protection Agency, Life Cycle Assessment: Principles and Practice, 2006
[4] Forum Journal, The National Trust of Historic Preservation, Summer 2007
