Demolition of the Century Building in St. Louis. Credit: Alan Brunettin. Source: New York Times
According to a new report, the demolition of aging skyscrapers and the construction of more efficient, modern replacements could be the best means of shoring up the sustainability and environmental friendliness of urban areas.
The study, conducted by consulting firm Terrapin Bright Green at the behest of the New York State Energy Research and Development Authority and other groups, concluded that the demolition of skyscrapers built in New York during the mid-20th century and the construction of larger replacements is a better option than retrofitting the existing structures.
According to the study, the construction of new buildings which are 44 per cent larger in scale would lead to five per cent less energy consumption, and the carbon cost of the construction of the new buildings with be offset within 15 to 28 years of their completion.
The study runs contrary to the assertions of urban conservation groups who, in addition to arguing that mid-20th century skyscrapers should be preserved as cultural heritage buildings, also claim that retrofitting and renovation are preferable to demolition and replacement on environmental grounds.
The Preservation Green Lab of the National Building Trust for Historic Preservation published a report last year that concluded that retrofitting and renovating old buildings was the best means of achieving energy efficiency in almost all circumstances.
The study analysed the 75-year life cycle of six different types of buildings in four American cities and pointed to energy savings of between four and 46 per cent achieved immediately, as opposed to years in the future.
Terrapin Bright Green’s Bill Browning points out, however, that the National Building Trust study understates the complexity of the retrofitting process and adds that certain old skyscrapers simply cannot be updated to meet modern benchmarks of efficiency.
“The tragedy of these buildings is that they can’t be adapted,” he said.
According to Browning, the very structure of many older buildings is insufficient to support the retrofitting of even simple measures, such as double or tripled glazed facades for insulation purposes.