Agenda - Planning Commission - 01/31/2013 - Special

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owe ors n own Zo n i n ByJeffrey S. Beiswenger, AIcP ulations Over the past several years there has been a paradigm shift in zoning practice with regard to sustainable planning and development. Policy makers, civic leaders, planners, architects, builders, and energy companies have started to recognize the link between energy consumption and development regulations. Many outdated zoning codes, in particular, are rife with provisions that lead to more energy consumption than necessary or prevent energy saving development techniques. Conversely, many newer codes already include provisions that promote energy conservation. This article explores ways in which energy consumption can be reduced directly or indirectly through zoning and other development regulations. The way that buildings are constructed, neighborhoods are laid out, transportation systems are connected, irrigation systems are designed, parking lots are lit, and even how local produce is grown can help reduce the consumption of electricity and other energy sources. While building codes may be the most direct way to address the energy efficiency of the building envelope, zoning regulations play a particularly important role in accomplishing energy efficiency in the space between buildings. In addition to helping conserve energy, zoning regulations can also playa role in promoting the use of alternative energy sources. Through favorable zoning provisions, communities can facilitate the installation of solar panels, wind turbines, and other renewable energy systems. UNDERSTANDING THE HEAT ISLAND EFFECT In order to understand the full impact that zoning regulations can have on energy efficiency it is important to understand the urban heat island effect. Ambient air temperatures in cities are often higher than in surrounding rural areas due to the presence of large expanses of unshaded building and pavement surfaces exposed to direct sunlight. Pavement surfaces exposed to direct sunlight can be 5o to 90 degrees hotter than the air, driving up the ambient air temperature, while shaded or moist surfaces remain close to air temperature. 92°F 9©'F ga°F 86'F Rural Suburban Commercial Do Residential In some hot cities, shading a building can save $5 to $25 per zoom' of roof area annually. If a city were able to eliminate the heat island effect entirely through extensive tree planting, the corresponding air conditioning savings would provide an Build It Smartt Ventura County, CaUfomla mown Urban Park Suburban Residential Residential Rural Farmland ® This graphic charts the differential between average late -afternoon temperatures over a range of lands —from undeveloped land to downtown — and shows how parks and open lands moderate high temperatures. Peak demand for electricity generally occurs on hot summer weekday afternoons, when offices and homes are running cooling systems, lights, and appliances. The urban heat island effect increases both overall electricity demand and peak demand. During extreme heat events the resulting demand for cooling can overload systems and require a utility to institute controlled, rolling brownouts or blackouts to avoid power outages. additional savings of $5 to $io per room' of roof area (Akbari 2005). THE TOP NINE WAYS TO POWER DOWN YOUR ZONING There are numerous zoning provisions that affect energy efficiency. These provisions may lead to direct energy savings by reducing lighting levels and the use of furnaces, air conditioners, hot water heaters, and water pumps. And they may ZONINGPRACTICE 12.12 AMERICAN PLANNING ASSOCIATION (page 2