Agenda - Planning Commission - 06/03/2010

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td0 Fences Allowed e 1 Story 9tiWings Alowed c J\ 2 Story Buil~ngs AflOwed ~(/I CourtesyofD6E/NRELandlhe5uztalnable BUildings lntlvsldes COUndI Above: Buildings, trees, or other obstructions should noT be located so as [o shade the south wall of solar buildings. Below: Trees and other landscaping features may be effectively used to shade east and west windowsfrom summer solar gains. West East allowances, buildings that are oriented perpendiculartothe front lot line on north-south streets can still take advantage of solar access. In mahy cases, there is no reason thatthe main building axis needs to face the street and thatyard requirements cannot be varied to allow for solar access. Obstacles can red uce not only the amount of solar available for winter indoor cli mate control, they can also limit daylighti ng and radiation fatting onactive - solar collectors and photovoltaic surfaces. Forexample,the limbs of a deciduous tree can reduce solar heat gains in passive solarbuild- ings, and-trees on the south side can all but destroy passive solar performance unless they are close to the building, with the lower - limbsremoved sothat winter sun can penetrate under the trees canopies. When used properly, landscaping can provide forshadingand ventilation. The i deal for shadi ng is the use of deciduous trees to shade the east, southeast, southwestand westsides ofthe build- ingand trellises with deciduous vi nes to shade the east windows during the summer months. Evergreens and shrubs can be used to block prevailing, cold wind in the winter and shade heat-absorbing paved areas duringwarm seasons. Also, trees, fences, and shrub- berycan beused to channel summerbreezes into the building. Daylighting design tools such as ENERGY to, available from the Sustainable Buildings Industries Council provide a simplified means for accounting for select obstacles and can be used to assist inset- tingyardand landscaping requirements for planned developments: Mote adequate algorithms fortools such as EnergyPlus are emerg- ing. Planning agencies maywish to draw upon the skills of energy analysts to help them establish yard and landscaping requirements where unique site conditions exist. ~ - Paved surfaces such as driveways, walks, and patios can re- Flectheat and glare into buildings through glazings. Development standards should encourage impervious surfaces to be located and designed to minimize these effects. Because solar building design requires operable windows for ventilation, the location ofoff-street parking is important. Large parking facilitiescan be a detrimentto indoor air quality ifvehide exhaust is allowed to enter the build ing through windows or vehts. Development standards should keep parking areas away from oper- ablewindows and vents and ensure that these areas are located so thatprevailingbreezesdonotcarryexhaustintobuildings. Communities may wish to consider the use or overlay zones or planned unit development restrictions to ensure that solar access is adequate. In some instances, it might be possible toapplythe prin- ciples ofform-based codes, although that option needs careful study to determ ine if it would be feasible. Aesthetics neednot 6e an issue in solar building design. There is sometimes a preconceived beliefthat buildings designed or renovated to use solar are "odd" in appearance. This is a mis- perception. Collectors needed for active solarsystems can be roof- integrated and the photovoltaic systems can function as theskin of the building, as roof shingles or standing seam roofing, as glazing for atria and covered walkways, or be integrated into building over- hangs or awnings. As for passive solar buildings, they can be of any architectural style. There are no special panels or other special details that announce that a building is passive solar. All its compo- nents orelements are designed as an integral whole beginning at thepredesign stage. - the angle of sunlight changes throughout the year. ~! Z~ 80 ~ ZONINGPRACTICE ado AMERICAN PLANNING ASSOCIATION Pe9e 6 Courtesyaf DOE/NRELand the Sustainable BUlldings lnduzNes Council ~~ [aurtesyofDOE/NREh Gedil-Ron ludkaR