It has become an oft-quoted adage of preservationists that “the greenest building is the one already built.”

First stated by Carl Elefante and quantified by the National Trust for Historic Preservations Trust's Green Lab study “The Greenest Building: Quantifying the Value of Building Reuse”, this statement and its implications has taken a long time to filter down to the workaday world of builders and architects. In fact, its opposite, “it would be cheaper to tear it down and start over” still holds sway. I have been hearing some architects, and lots of contractors say this for most of my 25 years of practice.

Lets take a look at what that later quote really means:

For the architect,

“cheaper to tear down” is either ignorance or ego inserting itself where common sense and data should win the day. I have had a number of initial interviews with new clients where they have told me that the previous architect they met with suggested they completely demolish the existing building in their best interest, financial and aesthetic. This may be true of a magnificently desperate building, one where the foundation has failed or is so hopelessly out of step with current zoning, building and energy codes, but it is rarely true in the case of most structures. Do these demolition architects really just want a clean slate to exercise their own design ambitions? Are they just ignorant of the real costs of making buildings, both embodied energy and operating costs? On the simplest scale, the single family house, it takes from 30 - 50 years for a new house to pay off the embodied energy lost in a house through demolition. Surely an experienced, talented architect can work with an existing building to bring it up to code, satisfy the client’s needs and desires and still be within the ballpark of budget and schedule while still making a building to be proud of!

For the contractor or builder,

the desire for demolition is, in my experience, most likely the fault of laziness and fear. The lazy part is inexcusable. Even if you demolition everything other than the foundation, if you rebuild on that foundation you have at least partially saved the cost of the structure of the building. As I mentioned above, there are buildings that are simply hopeless, at least at any reasonable cost, to bring back to life. We may choose to undertake those projects out of love of architecture, preservation or history, but those projects are not what I am talking about here. What I see most often are 1960s era houses that have issues - lack of insulation, bad wiring, poor windows - that can be solved, often much less expensively than replacing them individually or globally with an entire house demolition. “Just tear it down and start over”, is poften only making the contractor’s job easier at the expense of the building owner. Fear, however, is a very real and valid reason for a builder’s desire to start with a blank slate. So many building owners expect their well spent money to result in perfection. Even when clearly and explicitly discussed, contractor’s often get blamed for any and all imperfections after the work is complete. Why would any carpenter or plumber want to work on a project when they have to work with older, less-than-perfect construction, only to be held to an impossible standard. At least with all-new construction, the craftsman can be in more complete control of the final product (paradoxically, this “clean slate” deprives them of the scapegoat of “existing conditions”). Most contractors in the single-family home market, get paid as a percentage of the construction, so starting from scratch always make sense to them. So let’s all agree: homeowners - don’t hold out for perfection, especially if you’re saving money by keeping at least some part of the building. And contractors - unless you’re willing to throw in at least the foundation for free, don’t keep saying that all-new construction is always cheaper.

In many ways, the excuses given above for preferring demolition to renovation and reuse, can make some sense. For some buildings, the costs for renovation work can outstrip new construction. But that is almost never the case if we include the cost of the embodied carbon or energy in the existing structure. As a nation we are only now coming to understand the value and costs of this kind of thinking and it is my hope that realization will grow in all of us. Sure, as an architect, I love to have the creative freedom that a blank slate often implies. And I get to exercise that on new building sites all the time. But I take as much, or maybe more, pride in crafting buildings that are beautiful and the joy of the owners, while working with the existing building. Can it be a pain in the ass sometimes? Certainly. Do we get paid more for doing this kind of exhaustive work? Not as much as the time expended. Is it the right thing to do? In most cases, a resounding YES.