Category: Smart Design

While the greenest building may be the one that’s never built, the next greenest may be the historic one that’s being rehabbed.

A couple of years ago, the National Trust for Historic Preservation released a study quantifying the environmental benefits of rehabilitating old buildings instead of construction new ones. The study concluded that it can take “between 10 and 80 years for a new, energy-efficient building to overcome, through more efficient operations, the negative climate change impacts that were created during the construction process.”

Renovation of historic buildings has environmental costs, too—the materials used in renovation take energy to make and put in the building. But the environmental costs are 4%-46% less than those incurred by new construction.

The study offers some caveats. Renovation needs to improve the energy performance of the building to pay off, and you need to be careful about the types of materials you use. Turning warehouses into apartments, for example, requires many new materials and may not offer any environmental benefits over building new.

Making an older building meet the demands of the twenty-first century isn’t a simple process. In the Brooks House, for example, we had to add framing to increase the available space for insulation. Many of the windows were replaced, and others (the ones that were especially important historically) were rehabilitated to make them more energy efficient.

Many of the features of historic buildings are inherently energy-efficient. Large, operable windows allow daylighting and ventilation, meaning you can turn lights and air-conditioning off more often. Massive brick walls take a long time to heat up and cool down, which means that interior spaces stay comfortable longer without air conditioning or heat.

Many historic buildings are located in neighborhoods and downtowns that were built before the automobile was invented. Historic buildings make up Main Street, the icon of mixed-use walkability in this country. Kaid Benfield noted recently that “Main Street is a terrific model worth preserving and emulating…It has a human scale, neither skyscrapers nor sprawl, but something in between.”

We most often think of adaptive reuse in terms of restoration of buildings, but the term applies to landscapes and other structures, too. The High Line in Manhattan repurposed an elevated rail track along 10th Avenue to make a park and walking trail through downtown.The project was completed in phases; the first segment opened in 2009, the second in 2011. A third section has been proposed. Before the High Line could be planted, the railroad tracks and support structures had to be renovated, their lead paint removed, and their aging structures properly bolstered.The landscape, designed by James Corner Field Operations and Diller Scofidio + Renfro, echoes the overgrown railroad tracks one can spot throughout the country. Wildflowers and grasses are interspersed between planks and walking paths. Trees provide color and shade, as well as bird habitat, both needed in urban environments.The width of the walking paths varies along the High Line, narrow walking areas opening onto wider gathering and resting spots. In this way, it is much like an urban street that opens onto a plaza, where you might be able to eat at an outdoor café. (Indeed, there are food vendors along the path.)Unlike other parks in New York, High Line does not try to separate visitors from the city, or necessarily provide a respite. It is in the heart of the city (it even runs right through some buildings), and allows access to urban sights and sounds.The High Line presents one answer for what to do with our country’s (and our region’s) aging infrastructure.

Traveling the back roads of northern New England, it’s not uncommon to find long-abandoned carriage roads taken over by the wildflowers and forests. What if we did that intentionally on the unused railroad track the runs so often through the back sides of our towns and villages?

In Brattleboro, we are faced with aging bridges into New Hampshire. Among the many discussions about those bridges and what should happen to them, perhaps we should consider using a High Line approach on the old bridges once they are replaced, allowing better pedestrian access to Mount Wantastiquet and the Connecticut River.

(Photos are from the Friends of the High Line site.)