There are many components to every project; first is the parcel of land it occupies, ‘The Site’. As simple as the site might appear, it has unseen complexities that have long been overlooked. Land, in its natural state, is interconnected with the climate, plants, water, air, animals, insects,..its biodiversity supports a larger network that, left unaltered, exist in harmonious relationship. Since the industrial age, development has transformed the environment to provide convenience for humans at the expense of nature; denuding the land, reversing the natural stasis and replacing it with concrete, asphalt and water intensive lawns. Sustainable design aims to recreate a natural balance at every turn and in as many ways possible.
SELECTING A SITE
When selecting the site for a sustainable project one primary consideration is protecting greenfields, existing habitat & open space. Choosing an urban site has many advantages, as it reduces suburban sprawl which preserves rural areas, parks & farmlands, consentrating development in more densely populated communities with services (mass transit, schools, recreation, retail, commercial & industrial businesses, religious & cultural venues) and basic infrastructure (roads, water, power, waste collection and treatment). Living and working in more densely populated areas, if well designed, promotes more walking & biking and less vehicle use, thus reducing pollution. However, if selecting an urban site is not an option or preferred, attention can be made to developing the site with as little disruption as possible to the surrounding environment (watch for the future post: “Building in a Greenfield”).
DEVELOPING A SITE SUSTAINABLY
Once the site has been chosen, sustainable design of the project building(s), hardscapes and landscapes further reduce the negative impacts of development on the site by:
- reducing the footprint of the builing to maximize open space
- limiting the area of the site used for construction
- managing storm water runoff
- designing exterior lighting to reduce nighttime light pollution to support noctural animals and human enjoyment of the night sky
- using native plants in the landscape to reduce/eliminate irrigation and create habitat for insects & wildlife
- choosing exterior colors and materials that promote beneficial microclimate conditions
HEAT ISLAND EFFECT
This is a modern condition caused by the absorption of heat in urban areas by the materials used in the buildings and infrastructure; streets, parking lots, sidewalks,…. Certain materials absorb and hold heat while others reflect heat. The color of the material can also effect its ability to retain or shed heat. Each climate has different heating and cooling challenges, but in general and for large cities specifically, cooling tends to be a greater challenge. Everything, both natural and man-made, has an ability to retain or reflect heat, so care is taken when selecting colors and materials to reduce the heat island effect.
Ways to reduce Heat Island Effect are;
- reduce the amount of absorptive materials, such as pavement and building surface, exposed to the sun.
- choose reflective colors and materials
- provide shade for pavement and building surface
- maximize open space
One of the challenges for urban areas is the management of stormwater runoff. In the Pacific Northwest, there are additional concerns due to the the proximity of our urban development and roadways to the the Puget Sound and the tributaries feeding into it. Keeping these concerns in mind when designing site features can reduce or eliminate runoff and it’s negative impacts, as well as, provide alternate water supply for uses in the building and landscape.
Ways to sustainably managae stormwater runoff:
- minimize hardscaped areas-sidewalks, parking areas, patio/plaza
- use pervious pavement such as eco-pavers, grid paving.
- intersrupt pavement with vegetation to slow runoff and allow water to filter back into the surrounding soils.
- design a vegetated roof for the building
- funnel storm water into vegetated swales, bioswales, rainwater gardens, retention ponds, or catchment systems
There are real strides being made in the realm of LOW IMPACT DEVELOPMENT. Any project, large or small, can contribute greatly when designed with sustainability in mind. See what Washington is doing to promotea cleaner Columbia River, a cleaner Puget Sound a cleaner Pacific Ocean.