This, the second article in our series on green (sustainable) buildings examines the aesthetics and ambiance of green buildings, using green roofs to illustrate how additional synergistic benefits can be achieved without compromising the primary green design goals.
In case you missed the first article in our series it can be found at: The Green (or Sustainable) Building: Part I – What Is the Green Building DNA?.
Green Building Aesthetics
Many green buildings also seek to promote a green aesthetic and ambiance in their design and in how they are sited within the urban fabric they will exist within. Often these other additional design considerations flow from and are achieved in a synergistic manner by the structure’s other central design goals of reducing energy impact, water impact and providing a healthy inner space for its occupants. Sustainable buildings often promote a more livable environment and ambiance within and around them; enriching both the inner and the outer spaces.
Some green buildings, in fact can become remarkable iconic structures that enrich and become internationally recognized symbols of their cities. While this is certainly not necessary in order for a building to achieve it primary goals and it is certainly the case that many green buildings seem perfectly and even boringly ordinary on the outside and on the inside; on occasion a green building can aspire to and rise to a higher architectural realm and make a profound social/cultural comment, often achieving a remarkable level of beauty in the process.
Going for the greenest building possible, one that maximizes synergies to produce additional benefits and makes greatest use of the available on site resources can also impact the bottom line. We examine this phenomena in more detail in our post: Study Proves Viability of Ultra Green Buildings That Eliminate Energy and Water Bills Forever
Green roofs an Illustration of How Green Buildings can Produce other Valuable but Less Quantifiable Synergistic Benefits
For example, a green roof likely has the primary goals of reducing a buildings energy usage; the filtration of rain through the green roof’s living skin; storm-water retention as well as the promotion of material efficiency by virtue of its long durability when compared with conventional roofing surfaces. That same roof however may also provide many additional benefits to the building, to the surrounding urban landscape and to the larger environment.
For example a green roof will work to counteract and mitigate the heat island effect that degrades urban environments in the summer often making them unbearably hot. In fact a green roof will be very much cooler in a hot summer’s day than the ubiquitous black tar roof so common in cities all around the world. This not only has the benefit of helping to keep the building itself cool, but also acts to lower the outside ambient air temperatures over the roof surface area and in this manner acts to mitigate the urban heat island effect.
Many green roofs beautify the city landscape bringing much needed green into the urban desert of concrete and glass; some green roofs are works of true beauty and bring with them a grace and promotion of livability to their surrounding areas. In addition a green roof may also provide sanctuary and habitat to endangered species — right in the very middle of urban settings.
It is increasingly being recognized that green roofs can play an important role in the conservation of biodiversity in towns and cities, places where natural habitats are few and far between. Recent studies in Germany and Switzerland amongst other places, where green roofs have a longer history of adoption, have produced a small but growing body of evidence suggesting that green roofs can indeed provide living space for plants and animals, at least mobile species such as invertebrates and birds.
Green Roofs and Biodiversity
In fact some ecologists have begun looking for alternatives to the widely used sedum mats and utilitarian structures that characterize most green roofs. Some green roof architects and designers are beginning to consciously incorporate carefully thought out micro habitats into their green roofs that are customized to closely mimic the natural habitats of particular species. These green roof alchemists are beginning to add varied micro-topography to their designs, including tiny hollows and little micro cliffs, scattered rocks, dead wood and other naturally occurring rubble, as well as a more diverse vegetation drawn from a repertoire of native species important for the species habitat being designed.
Jeremy Lundholm, one of the authors of Green Roofs as Urban Ecosystems: Ecological Structures, Functions, and Services suggests that green roof designers should look to natural analogs of these man made environments, when designing green roofs. He suggests that green roofs are especially suited to mimic rock outcrop habitats such as cliffs, scree slopes, and limestone pavements. These naturally occurring types of habitats may be rare in nature, but they occur across all climatic zones and so can be used as a design template for green roof designers everywhere. They are especially indicated for green roofs precisely because they include suites of species adapted to shallow substrates and extreme temperature and moisture conditions; these are the very same conditions that prevail on green roofs. The natural rock barren ecosystems also typically include varied micro topography, increasing the diversity of the vegetation and providing a greater range of habitats for invertebrates.
Green Building Philosophy
All of these other green qualities are synergistic benefits that can be achieved in addition to and without compromising the green roofs principle design goals of providing a green skin that can absorb passing storm’s surges of rain, reducing storm runoff and water pollution; to filter rain water so that the water that does drain from the roof is clean and can be used for landscaping etc.; to provide an insulation skin that reduces summer heat gain and winter heat loss through the roof and in this manner reduces the structures energy requirements; and finally to promote the goal of material efficiency by being a very long lasting roofing material that will outlast by many times more commonly used roofing materials such as tar roofs.
But as we have shown green roofs can also be so much more than that. Achieving this kind of virtuous synergy is an important aspect of sustainable building design that, in my opinion is a core part of the green building philosophy.
Preview of Part III, the Next Article in the Green (Sustainable) Building Series
Part III in this series on green buildings, which will be published tomorrow, examines the importance of choosing a location for the building site as well as how the building is oriented within the site to make best use of available green assets such as sunshine and to fit into the urban fabric. It goes on to discuss the importance of multi-function landscaping for achieving energy and water efficiency goals and for reducing the buildings environmental impact.
