SSuummmmaarryyWhen focus is placed on the largest energy uses in a particulartype of building, incorporating pertinent enhancements in astandard design can readily improve energy efficiency. ThisDesign Brief summarizes the energy-efficiency design strategiesthat offer the greatest potential benefit in 11 building types.Although some of the measures discussed in this brief are fre-quently employed, others are seldom considered during thedesign process. This quick overview of energy-efficiency strate-gies appropriate to different types of buildings will allow design-ers to place a range of potentially useful options on the tableearly in the decision-making process.Energy intensity is presented as an indicator of the potential forcost-effective, energy-efficient design strategies in a particularbuilding type. design briefenergydesignresourcesoptions and opportunitiescontentsNot all energy-efficiency measuresare appropriate for all building types,but some are especially useful forparticular buildings. This Design Briefreminds designers and builders ofopportunities they should consider ineach of their projects.Introduction 2Energy Cost Intensity and Energy Use Intensity 2Energy-Efficiency Design Strategies for New Construction 4Schools 6Large Offices 8Small Offices 10Single-Story, Tilt-Up Retail Outlets 12Department, Mall, and Free-Standing Retail Stores 14Grocery Stores 16High-Rise Residential Buildings 18Hotels and Motels 20Laboratories 22Hospitals 24Warehouses 26page 2 options and opportunitiesIInnttrroodduuccttiioonnNumerous reports and briefs are aimed at providing the building commu-nity with information to improve the energy efficiency of the buildingswhere we work, shop, live, and learn. Although much practical wisdom iscontained in this vast literature, its very magnitude and breadth make itdifficult for designers to judge which of many options may apply to a spe-cific design job. Opportunities to save energy in buildings are a function of how muchenergy they use in the first place. Consequently, before focusing on spe-cific energy-saving measures, it is useful to understand how much energyvarious types of buildings typically consume.EEnneerrggyy CCoosstt IInntteennssiittyy aanndd EEnneerrggyy UUssee IInntteennssiittyyEnergy cost intensity is the annual cost of energy used per square foot.(Energy cost intensities discussed in this Design Brief are derived fromeQUEST, an Energy Design Resources energy modeling software pro-gram.) In general, as energy cost intensity increases, energy-efficientdesign strategies become more cost-effective. Figure 1 shows the range ofFigure 1: Approximate cost-intensity ranges for different building types in CaliforniaSchoolsLarge officesSmall officesSingle-story, tilt-upretail outletsDepartment, mall, andfree-standing retail storesGrocery storesHigh-rise residentialbuildingsHotels and motelsLaboratoriesHospitalsWarehousesEnergy cost-intensity range ($/square foot/year)Source: Constructive Technologies Group (CTG) Energetics Inc.Energy cost intensities for various building types are derived from eQUEST, an Energy Design Resources energy modeling softwareprogram. Actual cost intensities vary based on occupancy, usage, location, and building.012345678page 3options and opportunitiesenergy cost per square foot in different building types. The figure showsthat, in general, energy-efficient designs are especially cost-effective inlaboratories, hospitals, and grocery stores.Energy use intensity is the amount of energy per square foot a buildinguses annually from all metered sources. Energy use intensity is useful incomparing energy use in buildings of different sizes and occupancies. Thepie charts presented with each building type show energy use intensity.The charts (which are discussed in the introduction to each section) canbe used to compare energy use in different building types.Table 1 summarizes many of the most cost-effective energy design strate-gies according to their energy use intensity. Cells in Table 1 that are com-pletely filled in represent strategies that will target the most energy-inten-sive uses in a given building type. Implementing these strategies has themost potential for minimizing unnecessary energy use in the building type.On the other hand, cells that are completely clear indicate that this strate-gy will probably not significantly affect overall energy use in the finished building.For each building type, energy-efficiency measures are categorized according to their ability to minimize energy use.Table 1: Energy-efficiency measures for specific building typesSource: CTG Energetics Inc.Measures SchoolsLargeofficesSmallofficesSingle-story,tilt-up retailDepartment, mall, andfree-standingretail storesHigh-riseresidentialbuildingsGrocerystoresHotels andmotels LaboratoriesHospitals WarehousesHigh-efficiency lightingOccupancy sensorsEfficient parking lot lightingAutomatic lighting controlsSkylights and photocell controlsExterior shadingCool roofHigh-efficiency HVACDirect digital controlsVariable-speed drivesDemand-controlled ventilationDirect/indirect evaporative coolingWater-heating heat recovery= Highest potential= Some potential= Least potentialpage 4 options and opportunitiesEEnneerrggyy--EEffffiicciieennccyy DDeessiiggnn SSttrraatteeggiieess ffoorr NNeeww CCoonnssttrruuccttiioonnTable 1 lists many of the energy-efficient design strategies that are dis-cussed throughout this Design Brief. The following sections give briefdescriptions of these strategies. Specific applications of these strategies arediscussed under the building types where they are most applicable.Building envelope measures. The skin of a building should provide an appro-priate barrier between interior and exterior environments. Reflective sur-faces, especially on roofs and walls, will minimize the amount of solar heatthat penetrates a building. In particular, Energy Star–compliant “cool roofs”reflect a large portion of the sun’s heat energy back into the atmosphere.Optimized thermal insulation is essential to buffer the interior of the build-ing from the fluctuating temperature outside. In general, Title 24 insulationrequirements provide this optimization.Exterior shading, such as horizontal overhangs and vertical fins, is a goodway to decrease the amount of solar gain into a building and can alsoenhance the exterior design of the structure. In particular, shading fenes-tration from direct solar radiation has great potential
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