Preserved historic structures line main street Breckenridge giving the town much of its charm.

Much to the consternation of developers and redevelopment agencies intent on demolishing historic buildings and constructing new ones, these days, in the name of going green, preservationists are making the case that “the greenest building is the one already built.”

“When we first started working on sustainability issues and tried to get people thinking about the environmental value of reusing buildings, rather than tearing them down and building new ones, we were greeted with arched eyebrows and polite nodding heads,” explains Patrice Frey, director of sustainability research for the National Trust for Historic Preservation. “That’s changing now.”

“This whole idea that reusing existing resources — especially historic buildings — is the ultimate in recycling is beginning to get some traction,” agrees Donovan Rypkema, one of America’s most prominent and outspoken preservationists, and author of the classic book in the field, The Economics of Historic Preservation: A Community Leader’s Guide.

Helping historic preservationists present their case are new studies that calculate what is lost — in measurable environmental terms — when we tear buildings down and replace them with new ones. Plenty of studies have demonstrated the merits of constructing new green buildings, but until recently, there’s been relatively little data available on the economic and environmental benefits of building reuse. Some of the latest reports calculate both the enormous amount of energy and materials already locked into buildings (embodied energy), and the significant carbon emissions they represent.

Embodied energy is the energy consumed by all of the processes associated with the construction of a building, from the acquisition of natural resources to product delivery. This includes the mining and manufacturing of materials and equipment, plus their transport. A discussion of embodied energy first arose during America’s energy crisis in the late 1970s and early 1980s. Embodied-energy researchers developed a handy calculation: By entering a building’s size and type (residential, commercial, hospital, etc.), it was easy to do the math and come up with a quick estimate of the amount of energy saved by preserving a building.  Embodied-energy calculations had little influence on the old-versus-new building debate, though because it was believed that the embodied energy content of a building was rather small compared to the energy used in operating the building over its life. Most conservation efforts were, therefore, put into reducing operating energy by improving the energy efficiency of the structure

Nowadays, it’s accepted that embodied energy can be the equivalent of many years of operational energy, and that new construction requires enormous expenditures of energy and materials. A recent study by the Environmental Protection Agency estimated that 30 to 40 percent of natural-resource extraction every year goes to the building industry.

Meanwhile, to the delight of preservationists, old buildings have been adjudged to be surprisingly energy efficient. U.S. Department of Energy research on the energy performance of existing buildings ascertained that commercial buildings constructed before 1920 use less energy per square foot than buildings from any other period of time except after 2000. Older buildings, it seems, were constructed with high thermal mass, passive heating and cooling. And, obviously, were built to last.
Some builders acknowledge that historic commercial buildings use less energy than buildings of more recent vintage but insist the exact opposite is true of homes — the older the home, the worse the energy consumption is likely to be. Yes, but historic preservationists counter that recent studies show older homes can be remodeled and upgraded to meet energy standards at less cost — and at less cost to the environment — than tearing down and building new ones. That was the conclusion from a study in England by the Building and Social Housing Foundation and another in Scotland commissioned by Historic Scotland. Both studies also looked at the carbon impacts of building new homes compared to retrofitting old ones. The BSHF study commissioned by the Empty Homes Agency found it could take as long as 35 to 50 years for a new green home to recover the carbon expended during the construction process, while the Historic Scotland estimate was 15 to 20 years.
“The idea that even the most energy-efficient new house could require a minimum of 15 years to recover carbon ought to be reason enough to give us pause,” says Frey, “and take a second look at retrofitting our existing housing stock.”

Preservationists admit there is still some fuzziness in how exactly embodied energy and carbon emissions are measured. Noting that well over 40 percent of the nation’s carbon emissions come from construction and operation of buildings, The National Trust for Historic Preservation launched its Preservation Green Lab in Seattle to conduct further research. “The goal of research at Green Lab,” says Frey, “is to develop tools and resources to enable policymakers and decision-makers to get needed residential and commercial growth and at the same time protect what is already there.” (Run your dwelling through their embodied energy calculator here.) Most everyone, though, remains resistant to reusing and retrofitting buildings. Architects like to start from scratch, developers don’t want the hassles of rehabbing existing buildings, and new construction is a mainstay of the U.S. economy.

“The most unenlightened in this regard are the traditional environmental advocates and the U.S. Green Building Council and their LEED certification,” Rypkema jabs. “If it isn’t about a waterless toilet, solar panels or saving the rain forest, those groups don’t think it’s about the environment.” As Rypkema sees it, the environment and historic preservation have one thing in common: to understand their importance to society, you have to think long term. But in his experience, “The myopically short-term perspective of elected officials means they focus on the next election, not the next generation. “Fortunately, much policy on the national, state and local levels is effectively set by boards, commissions and public employees. With the right set of arguments, they are persuadable.”

Vacant Land For Sale

This has actually happened. A client contacts us. They want to build a new home. They’re about to close on a lot in a neighborhood development. At our introductory design meeting they  describe to us the kind of house they wish to build. A certain number of bedrooms, bathrooms. Energy effeciency. Passive solar design. Sustainable building. A two car garage. A relatively simple design without complex rooflines. And then we go to the site for the first time.

The site the clients had chosen was steep and in the trees. The building envelope was rather small, and because of height restrictions, the home would have to be built so that it stepped up and down the slope, complicating construction dramatically. Solar gain would be limited by shade and trees that by development covenant could not be removed. The steep lot also made it imperative that we locate the garage up-slope and to the front of the home so as to meet requirements that stipulated the maximum slope of the driveway at 7%. Expensive retaining walls would also be necessary. As much as we at Trilogy enjoy a challenge, we had to tell the clients that the lot they had chosen was not conducive to building the rather simple, super energy efficient home they were seeking. The clients did not take this news well for they loved that this lot was adjacent to community open space. They purchased the lot and hired another architect. About a year later the lot was back on the market, I suspect, because the clients had finally discovered for themselves how difficult a lot they had purchased.

Building in the mountain regions often means dealing with slope and trees. But even when the lot is relatively level, the site can still have an enormous impact on budget and design. Today, modern design and technology allows us to create passively energized, super insulated homes with dramatically decreased energy consumption.  But if the lot orientation is north or if the lot is shaded then energy costs will necessarily increase. Views are always a concern and in some developments, homes are built without taking into account that the vacant lot next door won’t always be vacant and views may be impeded when the neighbors build. Other subdivision and local government codes can also severely limit design opportunities. Some neighborhoods put limits on the amount of glass, or the use of solar panels, limiting the use of sustainable energy resources.

Which is why, if at all possible, the Trilogy Design Team likes to assist our clients in the selection of the site for their new home. If the lot is indeed going to constrain design, it’s a great idea to have the design and build team assess exactly what those limitations are going to be.

What would be the ideal site for the home of your dreams?