The Duel of Sustainability and Preservation
When it comes to sustainability and NIMBY sentiment, the preservationist mindset can brew its own unique vintage of opposition to environmental goals for building stock. The same boilerplate assumptions of solar panels and wind turbines that draw fire from locals can quickly be amplified when the project in question is the alteration of buildings that have been around for over a century. Even within the architectural community the topic of how to treat our historic building fabric is consistently a topic prompting controversy and healthy debate. While there is a great deal of cultural heritage locked into the innards of old buildings, the danger of "freezing" these structures in time is that we also end up maintaining their striking inefficiencies. As an aging country, we need ways to provide an evolutionary track for the older buildings that are often most notorious laggards in efficiency.
Sustainable development guru and fellow blogger, Kaid Benfield, wrote a post over the summer that was pointing at the difficulties of negotiating sustainability with our historic urban fabric. While architecture is a progressive art form that continues to evolve alongside our culture, there is a valuable place for historic structures amidst our built environment. History is a part of who we are and even where we are going. At the same time, older buildings are often the ones that levy the heaviest burden on our grid and, as a result, most in need of increased efficiency. In New York City, over half of the existing buildings were built before 1940 and most of them are projected to be here in 2030. Simply granting a by-your-leave for the sake of historical accuracy locks tens of millions of square feet in the wastefulness of antiquated construction methods.
That being said, the integration of sustainability into structures built without this goal in mind can be tricky. Twenty-first century tech and 18th century bricks and mortar don't always mix. There are some measures that simply don't lend themselves to 100-year old buildings, but that doesn't mean that the options available are few and far between. There are still a number of alternatives that can be instituted in order to maintain the integrity of both the interiors and exteriors of historic buildings.
The Municipal Arts Society, in association with COOKFOX Architects and Terrapin: Bright Green, recently released a free online manual with options for greening rowhouses targeted for preservation. In New York City, these parcels fall under the purview of the Landmarks Preservation Commission (LPC) after being determined to hold valuable historic significance. The publication is titled: "Greening New York City's Historic Buildings: Green Rowhouse Manual."
I had the good fortune of working on such a project during my time at lubrano ciavarra architects where we were tasked with the wholesale renovation of an historic brownstone in Brooklyn Heights. In this case, it wasn't the property, but the entire neighborhood that was Landmarked, making it an unavoidable part of the design process. Though the project was designed before the MAS manual was released, we ended up incorporating a number of the suggested components into the design that is currently under construction.
Saving Lost Energy
In many ways, the project revolved around the building's exterior envelope, which stood as a balance between two initiatives: On one hand the LPC needed to be satisfied with the aesthetic proposal presented to the community. On the other hand, the exterior walls (which were over 100 years old and devoid of insulation) needed to be properly fortified for our climate to help depress energy costs. Both goals needed to be achieved for the project to be successful. Through the lens of sustainability, one of the best ways to conserve energy is to make the most of what has already been used by tightening up the exterior envelope.
The exterior of the building had been severely neglected over time, suffering from a renovation in the 1960's that stripped the Italianate row-house of most of its exterior detail including the cornice, its chimneys and front stoop. The entire brownstone façade was covered with a brick veneer and its front door on the parlor floor was boarded closed and concealed. Quite simply, the building was in rough shape and not the favorite of the block.
The results of the project were for a full exterior restoration including returning the brownstone to its former glory, but this did not preclude us from shoring up the tightness of the skin—quite the opposite. Windows that needed to be replaced for the restoration were done so with high efficiency counterparts—double-glazed with a low-E coating. New windows also brought the opportunity to make sure the seal around the windows and their connection to the walls was up to snuff.
Moving further inward, the inside of the existing brick wall will receive a treatment of closed-cell, spray foam insulation to offer a tight seal and added R-value over the entire building–including the new roof. The building will go from having no insulation to some of the best the industry has to offer. To cap the structure off, the new roof surfaces will utilize a white EPDM membrane in order to deter solar heat gain. Not only does this help lower the home's energy use in the summer, but it helps break down the damaging effect of urban heat islands.
Due to the client being very interested in water efficiency, we worked to incorporate it into their specifications. The home ended up with low-flow toilets and low-flow lavatory faucets. For the family as a whole, these fixtures should help them save thousands of gallons of water a year. This summer has helped to remind Americans how important it is to treasure our water supply and take measures to reduce unnecessary uses. In older urban settings like New York City, the reduction of potable water use is just as important as the decrease in wastewater for combined sewer overflow (CSO) systems that can become easily taxed beyond capacity.
Each material carries its own energy footprint comprised of extraction, fabrication, packaging and transportation. The incorporation of recycled or rapidly renewable materials help lessen not only the harvesting of resources, but the expenditure of resources used on the production of virgin counterparts. The average home is rife with opportunities to utilize these options. In this brownstone, tile choices and terrace pavers incorporated recycled content on the buildings interiors. Outside, the wood components dictated by the historic design will find their new life from FSC certified lumber containing both recycled content (finger-jointed pieces into longer components) and water-based preservation measures. The result is sustainability on two fronts: a greener supply chain than traditional wood that will also last longer in an exterior environment.
Saving Produced Energy
The design team was able to step out ahead in lighting and work highly efficient LED lights into the recessed fixture scope of the project. Located in some of the high traffic areas, these fixtures represent the leading edge that the market has to offer for efficiency in artificial illumination. Coupled with some Energy Star appliances this made for a great start. Lights and appliances jump to mind when faced with the topic of increased efficiency, but energy use in the average American home is unquestionably weighted towards heating and cooling.
The combination of space heating, water heating and air conditioning equates to 72% of energy use in the average home according to the Department of Energy. High efficiency condensing boilers (fueled by natural gas) and ductwork that is insulated and properly sealed addressed helped curb wasted energy . Instead of the large tank we commonly expect for a hot water heater, this home has two tankless models—split between the upper and lower portions of the brownstone to minimize the energy needed to push hot water to the tap.
For the promotion of a healthy indoor environment, No-VOC paint was specified for all of the wall surfaces with low-VOC for all of the ceilings. Additionally, wood finished called for a low-VOC or water-based alternative to standard polyurethane. While these measures do not directly help efficiency, they improve health and the quality of life for the occupants.
One may notice that most of these measures do not contend with the exterior appearance of the building visible from the street, meaning that significant progress can be made on the sustainability front without having to throw down the gauntlet with preservationists. Despite the fact that there are no solar panels (we looked into the possibility), the building is still a head-and-shoulders improvement not only above what was existing, but also beyond what is achieved by many new buildings.