July 11, 2018
Out with the New, In with the Old
Over 90% of New York City’s building stock in the year 2050 already exists today.
Buildings in New York City account for almost three-quarters of the city’s current greenhouse gas emissions.
These two simple statements outline the challenge before us: to meet the New York City’s goal of reducing greenhouse gas emissions by 80% by 2050, an aggressive approach to energy reducing retrofits is essential. This challenge is one being faced by cities around the world, from from London to Guangzhou.
Redevelop vs. Retrofit
But if older buildings are such poor performers, why not demolish them and build newer, better performing ones? The choice between redevelopment versus retrofitting is not this simple. There is open debate among environmentalists over when it is appropriate or makes environmental sense to demolish versus retrofit. A report by Terrapin Bright Green concluded that it would be better to tear down and replace a prototypical Manhattan mid-century office building rather than retrofit it in terms of environmental impact. However, this result does not apply to all old buildings and it presents some practical constraints. We cannot feasibly rebuild New York or other major cities in a few decades – nor do we want to. The cultural and historic value of our existing buildings is essential in maintaining connection to our past, in keeping communities intact, and in establishing a sense of place. Can a case be also made for the value of existing building stock from a performance perspective? We think so.
Demolishing and reconstructing buildings has a large greenhouse gas footprint, requiring substantial energy to tear down the old structure and to produce, refine, and transport raw materials and assemble a new building. In many cases, the impacts of this process outweigh the reduced operational energy use of the new building, as BKSK partner Julie Nelson discusses in this post about the retrofits to the UN Headquarters.
This issue is being contemplated across the NYC building community. The NYC Technical Working Group (TWG), a multi-disciplinary collection of experts convened by the City of New York, has recently issued a Report that analyzed the energy use of the city’s existing buildings and identified energy conservation measures that would reduce the building-based emissions by 33%. Some of the measures target low-hanging fruit, such as improving burner controls for boilers, sealing elevator shaft roof vents, and installing de-stratification fans in larger heated industrial spaces. However, the report also makes it clear that to meet the necessary green house gas reduction goals, deeper retrofits of mid and large-sized buildings will be necessary. These findings throw down the gauntlet for building owners and architects: how can we effectively retrofit aging buildings to achieve significant energy savings without breaking the bank?
In New York, there are precedents for cost-effective deep energy retrofits: the Empire State Building underwent retrofits that reduced energy use by over 38% and over $4.4 million per year in savings while retrofits to the U.N. Headquarters building are projected to cut energy use by 50%. Both projects tell us is there is no single approach to effective retro-fitting. The work to achieve real savings requires the same creativity and out-of-the-box thinking that all good design problems present.
“These findings throw down the gauntlet for building owners and architects: how can we effectively retrofit aging buildings to achieve significant energy savings without breaking the bank?”
Renovated = Revitalized
Buildings do not need to be architectural icons or skyscrapers to merit extensive retrofits: every project presents the opportunity to contribute towards 2050 goals. 2 Lafayette Street, an interior office fit-out for The Office of Youth and Community Development (DCDY) and the Department for the Aging (DFTA) by BKSK, involved the renovation of seven floors of the historic Court Square Building, and achieved a LEED Gold certification. The team leveraged the necessary retrofitting and goal of improved energy performance to create a more pleasant working environment. To address the drafty conditions of the existing space, the team researched wall, ventilation, and window options. Contrary to conventional industry thinking, they discovered that keeping the existing windows was the best option in terms of performance, comfort and return on investment. Starting with thermal imaging, the team saw that the primary cause of air leaking and thermal transfer was the poor seal between window and jamb, rather than through the window unit itself. They analyzed performance of the existing double-glazed window against current window units available on the market. The window comparison revealed that there was not significant improvement to be achieved by window replacement. Instead, the team added interior insulation, new seals, and splays around the windows to improve daylight penetration into the space while minimizing air infiltration and improving U value of the whole assembly. This approach, (coupled with a new demand control ventilation system), vastly improved the energy performance and comfort of the offices in a way that was unexpected and experiential.
(explore more adaptive reuse/renovation projects by BKSK here).
“Retrofitting can be an opportunity to not only save on energy and operational costs but create high-quality, desirable spaces.”
Achieving ambitious climate goals like New York City’s 80×50 initiative will require clever retrofit and adaptive reuse solutions – just the sort of creative problem solving that architects are well-suited for. Achieving high energy performance while preserving or enhancing the existing building is no small feat. Energy conservation measures and the quality of spaces need to be balanced against the preservation of existing landmarks and financial costs. But these constraints establish opportunities for design solutions that celebrate the historic character of the city, improve quality of life, and reduce environmental impact. Perhaps future architects will be most celebrated for their abilities to skillfully intervene in existing buildings.
photos by upsplash users: Anthony Delanoix, Tom Barrett, Tua Nguy N Minh, Todd Quackenbush. 2 Lafayette by Raimund Koch and BKSK.