Chapter 8: Whole Building to Zero Net Energy

Evolution toward Green Buildings and Communities

• Energy in buildings has traditionally focused on the thermal envelope and HVAC systems.

• Recently, greater attention has been given to electricity due to the growth of appliances and equipment.

• Whole building energy approach considers the comprehensive energy usage in buildings, including electricity, heating, cooling, and appliances.

• Occupant health and environmental impacts are important considerations in design and construction.

• Green Building movement integrates considerations for health, embodied energy, materials, and waste management.

Evolving Considerations in Building Energy

• Building energy considerations have evolved over time.

• In the 1960s and 1970s, insulation levels were the focus.

• In the 1970s, air conditioning and ventilation became important factors.

• More recently, electrical appliances and lighting have been recognized as significant energy users.

• Whole building life-cycle considerations are emerging in some guidelines and rating systems.

• Emerging technologies like demand response wireless controls and rooftop solar PV have introduced smart buildings and zero net energy buildings (ZNEBs).

• The broader role of buildings in community energy, transportation energy, and land use is being considered.

Whole Community Energy

• Whole community energy uses buildings as the centerpiece of sustainable community energy.

• It focuses on building design and operations, materials and embodied energy, on-site and community generation, and efficient land use and transportation.

Driving Forces of the Green Building Movement

• New building technologies and practices have made energy improvements more available and affordable.

• Improved methods for energy, economic, and life-cycle analysis have clarified the value of improved efficiency.

• Government and utility programs have educated builders and consumers and reduced initial energy investment costs.

• Third-party rating and certification programs provide clear guidelines for builders and consumers.

• Innovative architects and builders have improved building design and practice.

• Growing consumer demand for energy-efficient and environmentally-friendly buildings has pushed for more efficient buildings.

• Building energy codes and equipment standards continue to adopt innovations in technology, design, practice, and rating systems.

Evolving Considerations in Building Energy (Table 8.1)

• 1960s-1970s: Emphasis on building envelope and heating operating energy.

• 1980s: Addition of infiltration and HVAC, heating, and air conditioning (AC) operating energy.

• 1990s-2000s: Whole building energy approach, including heating, AC, appliances, and lighting energy.

• 2000s-2010s: Whole building life-cycle (WBLC) considerations, including health, environmental impacts, and embodied energy.

• 2010s+: Smart buildings with demand response capabilities.

• 2010s+: Zero net energy buildings with on-site generation.

• 2010s+: Whole community energy with distributed resources, district energy, site and neighborhood design, and sustainable mobility.

Evolution of Energy-Efficient and Green Buildings

1915

• Building Officials and Code Administrators (BOCA) formed in response to need for fire and electrical safety.

1920s

• First codes introduced for furnaces and ducts.

• First insulation codes for buildings not developed until the 1970s.

1974

• California Energy Resources Conservation Act establishes first appliance energy standards.

1975

• ASHRAE Standard 90-1975; split to 90.1 (commercial) and 90.2 (single-family residential); subsequent versions: 1980, 1989, 1999, 2004, 2007, 2010, 2013, 2016.

• Federal Energy Policy and Conservation Act established State Energy Conservation Program (SECP), providing funding to states for energy offices and plans if states adopted building energy codes based on ASHRAE 90-1975.

1978

• California Title 24 consolidates all building codes in what has become the most comprehensive and stringent energy building code in the country, with major revisions now on a triennial schedule, most recent version 2016, effective January 1, 2017.

1983

• BOCA and Council of American Building Officials (CABO) develop Model Energy Code (MEC-1983); subsequent versions: 1986, 1989, 1992, 1993, 1995.

1985

• Austin’s (Texas) municipal utility Austin Energy establishes ENERGY STAR program to label appliances and buildings meeting minimum efficiency standards; program is renamed Austin Green Building Program in 1991.

1986

• Federal Appliance Energy Conservation Act followed California’s lead in creating national efficiency standards for appliances and equipment; standards are updated on a continuing basis.

1992

• Federal Energy Policy Act required state energy building codes meeting, at a minimum, MEC-1992 and ASHRAE 90.1-1989.

• EPA establishes ENERGY STAR program, a certification and labeling program to promote energy efficiency, first for office equipment, then expanding over the next decade to residential appliances, HVAC, and homes.

• U.S. Green Building Council (USGBC) established by some building organizations and equipment manufacturers “to promote buildings that are environmentally responsible, profitable, and healthy.” USGBC worked initially to develop certification protocol with American Society of Testing and Materials (ASTM) before deciding to develop its own Leadership in Energy and Environmental Design (LEED) protocol in 1998.

1994

• International Code Council (ICC) is formed by BOCA, CABO, and other organizations to better coordinate building code activities.

1995

• ENERGY STAR Homes program is established by EPA for new houses exceeding MEC-1993 by 30%.

• The Residential Energy Services Network (RESNET) is founded by the National Association of State Energy Officials and Energy Rated Homes of America to develop a national market for home energy rating systems (HERS) and energy-efficient mortgages. RESNET’s HERS is used for ENERGY STAR homes.

1996

• ISO 14000 standards become effective, establishing certification standards for energy management systems (14001, first version in 1996), environmental auditing (14011, 1996), environmental labels (14021, 1999), and life-cycle assessment (14041, 1998).

• The Passivhaus Institute is founded by Wolfgang Feist in Darmstadt, Germany, to promote super-efficient building design standard adopted widely in Europe.

1998

• ICC develops the International Energy Conservation Code (IECC), a model code that replaces MEC. IECC is incorporated into ICC’s International Residential Code (IRC). Subsequent versions on triennial schedule: 2003, 2006, 2009, 2012, 2015.

• USGBC releases LEED version 1.0 for new construction and pilots the protocol in 1999. LEED-NC 4.0 is released in 2013.

2004

• California Executive Order S-20-04 announces state Green Building Action Plan to promote LEED certification of all state buildings and improve commercial energy use by 20% by 2015.

2005

• USGBC develops new protocols for homes (LEED-H), commercial interiors (LEED-CI), core and shell buildings (LEED-CS), and existing buildings (LEED-EB). LEED-H incorporates many ENERGY STAR criteria.

2006

• Upgrades in state building energy codes, federal SEER-13 standard, and new technologies prompt ENERGY STAR home rating system to adopt whole house operating energy criteria and revised HERS.

2007

• The Passive House Institute US (PHIUS) was established in the U.S. to adapt European Passivhaus principles and standards to U.S. climate zones and energy economics, certify buildings meeting these standards, and train certifiers.

• California Energy Commission (CEC) Integrated Energy Policy Report recommends that Title 24 energy standard updates require zero net energy performance in new residential buildings by 2020 and commercial buildings by 2030.

2008

• The 2010 California Green Building Standards Code CALGreen approved effective January 2011 and incorporated as Part 11 of the California Building Code. CALGreen triennial update, latest update 2016.

• USGBC, the Congress for New Urbanism, and the Natural Resources Defense Council launch LEED Neighborhood Development (LEED-ND).

2010

• European Union enacts Energy Performance of Buildings Directive (EPBD), requiring member states to ensure all new buildings are “nearly zero energy buildings” (NZEB) by the end of 2020 and that all new public buildings are NZEB after 2018. NZEB are high performance, so required energy can be supplied by renewable on-site or district energy system.

2012

• 2012 IECC Residential Energy Code launched, 30% more efficient than 2006 IECC and 15% more efficient than 2009 IECC.

2013

• USGBC approves LEED v4, launched in November 2013, but previous version LEED 2009 can be used until October 2016.

2015

• PHIUS launched PHIUS+2015 Climate-Specific Passive Building Standard for North America.

• CEC enacts 2016 Title 24 building energy efficiency standards with 28% less energy than 2013 standards, which puts the code on track to achieve its goal to require zero net energy for all new residential buildings by 2020.

2016

• ASHRAE approves 90.1 2016 Energy Efficiency Standard for commercial buildings, which saves a national aggregated 34% in energy use and cost compared with its 2004 standard.

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• The interaction between technology, market, and codes has led to improved efficiency in new buildings.

  • New technologies are reflected in ratings and the market, and ultimately in regulatory codes.

• Energy rating systems like ENERGY STAR and LEED are more efficient than the average market and codes.

• Cost-effective technology, design, and practice improve over time, leading to modifications in rating systems and codes.

• Ambitious codes and standards are driving cost-effective technologies and market penetration.

• The chapter discusses the evolution of energy considerations in buildings, moving from a focus on the building envelope to a whole building and whole building life-cycle approach.

• Whole building energy technology improvements for appliances, equipment, and lighting are reviewed.

• The chapter also addresses whole building life-cycle issues of embodied energy and materials.

• Building energy codes and Green Building rating systems represent considerations of energy efficiency and thermal energy efficiency.

• Progress toward zero net energy buildings and whole community energy is presented.

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• Whole building energy looks beyond the building envelope and considers energy needs in building operation.

• Thermal needs for space heating, cooling, and water heating account for a significant portion of energy use in residential and commercial buildings.

• Building envelope improvements can reduce space conditioning needs, but energy is still consumed in HVAC and water heating equipment.

• Lighting, refrigeration and cooking, electronics and computers, and other uses also contribute to energy consumption in buildings.

• Efforts to improve energy efficiency in buildings must address the efficiency of consuming devices.

• New technology, stimulated by government consumer standards and research, has significantly boosted lighting and appliance efficiency.

• Appliance and equipment standards and LED lighting are projected to achieve massive electricity and utility cost savings compared to no standards and LED.

• Appliance and equipment efficiency standards, labeling, and the ENERGY STAR program have driven technology and market penetration.

• California established the first appliance standards, which led to nationwide federal standards.

• Most standards are developed by the U.S. DOE, but some are set by Congress and some states have standards that go beyond federal requirements.

• The process for developing new standards involves product manufacturers and energy efficiency proponents.

Page 7

• Effects of standards on energy use and initial cost of appliances

  • New refrigerators in 2014 use 60% less energy than 1990 models, are 15% bigger, and cost 30% less

  • 2013 model dishwasher uses half the energy of a 1990 model and is 20% cheaper

  • 2015 clothes washer is bigger, costs less than a 1993 model, and uses 80% less energy

• National standards for heat pumps (HPs) and central air conditioners (CACs) were established as part of the National Appliance Energy Conservation Act

• Table 8.2 shows residential and commercial building energy consumption by end use

  • Heating accounts for 44.7% of residential energy consumption and 27.8% of primary energy consumption

  • Cooling and ventilation account for 9.2% of residential energy consumption and 15.1% of primary energy consumption

  • Water heating accounts for 16.4% of residential energy consumption and 12.9% of primary energy consumption

  • Lighting accounts for 5.9% of residential energy consumption and 9.7% of primary energy consumption

  • Refrigeration accounts for 3.9% of residential energy consumption and 6.4% of primary energy consumption

  • Cooking accounts for 3.7% of residential energy consumption and 3.7% of primary energy consumption

  • Electronics and computers account for 6.2% of residential energy consumption and 10.0% of primary energy consumption

  • Other or unspecified accounts for 6.8% of residential energy consumption and 9.4% of primary energy consumption

• Table 8.3 shows estimated U.S. 2030 savings from appliance standards, LED lighting, wind, and solar generation

  • Appliance efficiency standards are projected to save 990 TWh/yr of energy and result in $100 billion in consumer savings annually by 2030

  • Projected LED lighting is expected to save 395 TWh/yr of energy and result in $40 billion in consumer savings by 2030

  • Projected wind power is expected to save 243 TWh/yr of energy

  • Projected solar power is expected to save 36 TWh/yr of energy

• Figure 8.2 shows U.S. 2030 electricity savings and generation from appliance standards, LED lighting, wind, and solar

  • Appliance efficiency and LEDs are shown to have a greater impact on electricity savings and generation compared to wind and solar

Page 8

• Table 8.4 shows appliances, equipment, and lighting with efficiency standards

  • Lists the last standard effective date, update expected effective date, and cumulative consumer savings for each product category in residential, commercial, and industrial sectors

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• Cooling and heating standards for buildings have been updated over the years.

  • In 2001, the cooling standard was updated to SEER 13 and the heating standard to HSPF 7.7.

  • In 2011, revised standards were set for CAC, HP, and gas furnaces.

  • In 2015, the 2011 standards were made effective for HP (SEER 14, HSPF 8.2) and for CAC (SEER 14 in the South and SEER 13 in northern states).

• The market distribution of CAC and HP models has been affected by the efficiency standards.

  • In 2001, the majority of HP models had HSPF less than 7.7.

  • In 2012, the majority of HP models met or exceeded the new 8.2 standard.

  • Similar trends were observed for CAC models.

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• Efficiency standards have driven down energy use while prices have dropped and volume has increased.

• The ENERGY STAR program, started in 1992, promotes the sales of the most efficient appliances and equipment.

• ENERGY STAR products exceed federal standards by 15% or more.

• The program has increased the market for efficient appliances, with 5.2 billion ENERGY STAR products sold.

• The program is integrated with the federal EnergyGuide label, which provides efficiency information for all appliances.

• Market penetration for selected equipment in 2013 was as high as 74% for refrigerators and 84% for televisions.

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• In 2001, the majority of models sold had a SEER less than 13.

• By 2012, the majority of models sold had a SEER greater than 14, with a significant percentage exceeding SEER 15 and SEER 16.

• The first national gas furnace efficiency standards took effect in 1992, requiring a minimum AFUE of 72%.

• In 2007, the standard was updated to 80%.

• An agreement in 2009 included different standard levels in three climate regions.

• In 2012, the implementation of the standards for nonweatherized gas furnaces was halted due to litigation.

• In April 2014, a settlement was approved, rolling back the gas furnace efficiency standards to 80% for nonweatherized gas furnaces.

• In March 2015, a new standard increasing the AFUE for nonweatherized furnaces was proposed.

• As of August 2017, a final rule has not been issued, and it is likely that the proposed rule will be scaled back by the Trump administration.

Page 11: Whole Building to Zero Net Energy

• Lighting consumes about 30% of U.S. residential and commercial building primary energy and 12% of total primary energy.

• LED lighting has the potential to cut general lighting energy use in half by 2030, saving as much as 395 TWh and $40 billion per year in 2030.

• Lighting standards enacted by Congress in 2005 require traditional lighting applications to be 27% more efficient than standard incandescent lamps.

• LED lighting benefits include high efficiency, long life, declining cost, good light quality, and excellent light utilization and functionality.

• ENERGY STAR appliances market penetration varies, with some equipment having federal efficiency standards and others not.

• Sample Appliance EnergyGuide Label provides information on energy consumption.

Page 12: Energy for Sustainability

• LED life-cycle energy (LCE) in 2015 is less than half that of CFL and 2011 LED, and one-seventh and one-sixth of incandescent and halogen lamps, respectively.

• LED A-19 standard screw-in bulbs became cost competitive with CFLs in 2015.

• Projected lighting primary energy consumption from 2015 to 2035 shows improvement with LED luminaire efficacy.

• Market penetration of LED lighting is still small, indicating potential for future energy and cost savings.

• Organic LED (OLED) technology offers advantages such as low illuminance, thin profile, and unique lighting sources.

• Cost of OLED panels is projected to decrease, and OLED panel efficacy is expected to improve.

Page 13: Whole Building to Zero Net Energy

• Different lighting applications have varying LED market shares, with predictions for increased market share in 2020 and 2030.

• OLED technology offers unique lighting sources but is still cost-prohibitive.

• Smart buildings and smart homes utilize control devices to manage energy use and optimize electricity consumption.

• Wireless technology allows integration of control devices into demand response systems for efficient timing of demand and reduction of peak load periods.

Page 14: LED Lighting Applications and U.S. Market Share

• General service LED lighting market share:

  • 2014: 4%

  • 2020: 55%

  • 2030: >99%

• Types of general service LED lamps:

  • A-type and other general lamps

• Directional LED lighting market share:

  • 2014: 6%

  • 2020: 26%

  • 2030: 74%

• Types of directional LED luminaires:

  • Reflector, recessed, accent, spotlight luminaires

• Decorative LED lighting market share:

  • 2014: 1%

  • 2020: 31%

  • 2030: 94%

• Types of decorative LED lamp shapes:

  • Bullet, candle, flare, globe lamp shapes

• Linear fixture LED lighting market share:

  • 2014: 4%

  • 2020: 44%

  • 2030: 83%

• Types of linear fixture LED luminaires:

  • Troffer, panel, suspended, pendant luminaires

• Low/high bay LED lighting market share:

  • 2014: 3%

  • 2020: 36%

  • 2030: 73%

• Types of low/high bay LED luminaires:

  • Low and high bay luminaires

• Total indoor LED lighting market share:

  • 2014: 3%

  • 2020: 42%

  • 2030: 81%

• Street or roadway LED lighting market share:

  • 2014: 21%

  • 2020: 83%

  • 2030: 99%

• Types of street or roadway LED luminaires:

  • Luminaires used in roadways

• Parking lot LED lighting market share:

  • 2014: 12%

  • 2020: 74%

  • 2030: 99%

• Types of parking lot LED luminaires:

  • Parking lot illumination

• Garage LED lighting market share:

  • 2014: 8%

  • 2020: 67%

  • 2030: >99%

• Types of garage LED luminaires:

  • Attached and standalone parking garage luminaires

• Building exterior LED lighting market share:

  • 2014: 11%

  • 2020: 71%

  • 2030: 99%

• Types of building exterior LED luminaires:

  • Fixtures, façade, spot, flood, walkways

• Total outdoor LED lighting market share:

  • 2014: 14%

  • 2020: 75%

  • 2030: 99%

• Total LED lighting market share:

  • 2014: 6%

  • 2020: 48%

  • 2030: 84%

Page 15: Determining Building Electricity Needs

• Electricity is delivered to the electrical meter on a house through utility distribution lines.

• The electrical meter measures power and time to determine cumulative electrical energy used.

• Utility bills can be used to monitor electricity use, while the electric meter measures energy use and power demand.

• Energy use of load devices (lights, appliances) is calculated by multiplying their power rating by the number of hours they are on.

• Residential electricity bills are based on energy (kWh) used, while large users like commercial buildings are billed on both energy used and peak power demand.

• Energy consumption of appliances controlled by a thermostat can be measured using submetering devices or estimated from EnergyGuide labels.

• Table 8.7 provides a spreadsheet for estimating electrical energy use and cost in a home.

Page 16: Building Energy Codes and Standards

• Building codes set minimum standards for new construction.

• Energy codes for building insulation became widespread in the U.S. in the mid-1970s.

• Federal Energy Conservation Act provided funding for state energy programs if the state adopted an energy building code.

• There is no federal building energy code in the U.S., but many states have developed their own codes.

• This section describes code development and adoption, typical code requirements, and code assessment.

Page 16: Smart Home Devices for Monitoring and Controlling Energy Use

• Smart home devices for monitoring and controlling energy use include:

  • Smart meter

  • Gateway

  • Interactive use portal

  • In-home energy display (IHD)

  • Programmable communicating thermostat (PCT) + HVAC

  • Smart appliances

  • Plug load controllers

  • Solar PV system

  • Electric vehicle charging station

  • Energy storage

• Figure 8.10 shows examples of smart home devices.

• These devices allow users to view and manage their energy consumption in real-time and adjust temperature and appliance operation based on preferences.

Page 17:

Building Energy Code Development and Adoption

• Some states develop their own unique codes, while others adopt model codes developed by organizations like the International Code Council (ICC) and the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE).

• ICC's Model Energy Code (MEC) was developed in 1983 and replaced by the International Energy Conservation Code (IECC) in 1998.

• The IECC is updated every 3 years, with the most recent update in 2015.

• ASHRAE's 90.1 energy code for commercial buildings was first developed in 1975 and is also updated every 3 years, with the most recent update in 2016.

• The adoption of building energy codes for residential buildings varies among states, with some having no state code, some having less efficient codes than IECC 2009, and others having codes equivalent to or more efficient than IECC 2009.

• Similar patterns can be seen in the adoption of ASHRAE 90.1 code by states.

Monthly, Annual Electricity Consumption Calculator

• The table provides information on the electricity consumption and cost for various appliances in two scenarios: a less efficient case and a more efficient case.

• The appliances include a refrigerator, color TV, stereo, computer, lights (indoors and outdoors), washing machine, clothes dryer, room air conditioner, ceiling fan, furnace fan, clocks, nightlights, dishwasher, microwave oven, toaster, and vacuum cleaner.

• The total electricity consumption and cost are calculated for each scenario.

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Typical Building Energy Code Requirements

• The code requirements for energy efficiency become more stringent with each 3-year upgrade.

• A comparison of energy usage between houses built to different code versions shows significant improvements in energy efficiency over time.

• A house built to IECC 2015 code uses about 60% of the energy of a pre-1983 house built to Standard 90-75.

• A commercial building built to ASHRAE 90.1 2013 uses about 53% of a 1975-1988 building.

• The biggest improvements in energy efficiency for IECC came in the 2009 and 2012 versions, and for ASHRAE 90.1 in 2010.

• ACEEE projects further improvements in subsequent model code upgrades to achieve zero net energy (ZNE) buildings by 2030.

Assessing Code Compliance and the Home Energy Rating System (HERS)

• DOE's building energy codes program provides methods to assist users in assessing compliance with the codes.

• REScheck and COMcheck are online and downloadable software methods that evaluate building compliance.

• The Home Energy Rating System (HERS) is used as an alternative performance compliance pathway in the IECC 2015 code, allowing for energy rating index (ERI) calculations.

• EPA's ENERGY STAR Home and DOE's Zero-Energy Ready Home (ZERH) programs go beyond the IECC in specifying ENERGY STAR lighting, HVAC equipment, and appliances.

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• Improving IECC and 90.1 Building Energy Standards over Time and Pathway to ZNE by 2030

• IECC Requirements for Residential Buildings 2006-2015

  • Building Envelope Airtightness (ACH50)

    • None

    • ≤7.0

    • ≤3.0 to ≤5.0

    • ≤3.0 to ≤5.0

    • ≤3.0 to ≤6.0

    • ≤1.5 to ≤3.0

  • Duct leakage (CFM25/100 ft2 conditioned floor area)

    • None

    • Total ≤12 or to leakage to outdoors ≤8

    • Total ≤4; blower door verified

    • Total ≤4; blower door verified

    • Total ≤6 or leakage to outdoors ≤4

    • All ducts within thermal and air barrier boundary

  • Insulation, ceiling

    • R-30 to R-49

    • R-30 to R-49

    • R-30 to R-49

    • R-30 to R-49

  • Insulation, wall

    • R-13 to R-21

    • R-13 to R-21

    • R-13 to R-20+5 or R-13+10

    • R-13 to R-20+5 or R-13+10

  • Windows, U-factor

    • 1.20 to 0.35

    • 1.20 to 0.35

    • None to 0.32

    • NR to 0.32

    • 0.60 to 0.30

    • 0.40 to 0.27

  • Windows, solar heat gain coefficient

    • None to 0.40

    • None to 0.30

    • None to 0.25

    • None to 0.25

    • None to 0.30

    • None to 0.25

  • Lighting, HVAC, Appliances

    • High-efficacy lighting

      • None

      • 50% of fixtures

      • 75% of fixtures

      • 75% of fixtures

      • ENERGY STAR 80%

    • HVAC

      • None

      • Controls

      • Controls

      • Controls

      • ENERGY STAR

    • Appliance efficiency

      • None

      • None

      • None

      • None

      • ENERGY STAR

  • Compliance Pathways, HERS Rating

    • Compliance pathways

      • Prescriptive, U-factor, performance

      • Prescriptive, U-factor, performance

      • Prescriptive, U-factor, performance

      • Prescriptive, U-factor, energy rating index (ERI)

    • HERS rating

      • 100

      • 85

      • 70

      • 55 (ERI)-68

      • 70

      • 55

  • Range of values represents varying requirements for different climate zones.

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• REScheck and HERS rating systems

  • REScheck requires basic information about the home to be constructed

  • HERS has become a standard rating system for residential buildings in the U.S.

  • HERS score spectrum

    • More than 100 for existing homes

    • 100 for 2006 IECC

    • 70 for ENERGY STAR 3.0 homes

    • 55 for 2015 IECC ERI and DOE ZERH

    • 38 for Passive Houses

    • 0 for ZNE homes

  • HERS raters varied widely on the same house and generally overestimated energy consumption

  • California has developed its own HERS program based on its 2008 code, which is more stringent than 2006 IECC

  • CalHERS rating of 100 is equivalent to a RESNET HERS of 80

• Whole Building Life Cycle: Embodied Energy in Buildings

  • Building codes and appliance standards are beginning to address whole building energy considerations

  • Embodied energy and life-cycle environmental impact factors are part of the whole building life-cycle approach to building efficiency

  • Life-cycle analysis considers cradle-to-grave energy, economic, and environmental costs and benefits

  • Green Building rating and certification systems are incorporating these considerations

  • Energy used to operate buildings underestimates the energy cost because it does not include the energy needed to make them

  • Embodied energy is involved in building materials

Page 21:

Whole Building to Zero Net Energy

• Embodied energy in buildings can be as much as 15 times a building's annual operating energy.

• California has the most stringent building energy efficiency code in the nation.

• California's Title 24 standards were initiated in 1978 and have been continually updated.

• The California Long-Term Energy Efficiency Strategic Plan established goals of zero net energy (ZNE) for all new residential units by 2020 and all new commercial buildings by 2030.

• The 2016 Title 24 requirements reduce energy use by another 28% compared to the 2013 code.

• The 2016 changes are estimated to add an initial cost of $2700 but save $7400 in energy costs.

• The 2016 upgrade puts the code on track for ZNE-ready (ZNER) energy use in the 2019 code.

• California also established the Green Building Standards Code (CALGreen) in 2010, which requires new buildings to reduce water use, increase building system efficiencies, divert construction waste from landfills, and install low-pollutant emitting materials.

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Life-Cycle and Embodied Energy in Buildings and Materials

• Analyzing embodied energy of buildings is important for improving life-cycle analysis and considering the energy and environmental effects of materials used.

• Embodied energy is mostly a one-time initial cost, but there are also recurring embodied energy requirements for building maintenance and renovation.

• Cumulative embodied energy increases slightly over a 100-year life cycle due to recurring renovation and maintenance.

• Cumulative operating energy increases dramatically over a 100-year life cycle.

• It takes about 10 years for the cumulative operating energy to reach the embodied energy for high-operating cases and 20 years for low-operating cases.

• Recycled materials and indigenous materials found locally tend to have much less embodied energy than virgin or distant materials.

• Wood has the least embodied energy on a per-mass basis, followed by brick, concrete, plastic, glass, steel, and aluminum.

• Engineered materials have higher embodied energy than lumber but can take advantage of residual material that would otherwise be wasted.

• Plastics and composites generally have higher embodied energy than natural materials.

• The Consortium for Research on Renewable Industrial Materials (CORRIM) investigates the life-cycle energy and environmental costs of various wood products relative to other building materials.

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Wood products in buildings and carbon emissions

• CORRIM assessed carbon emissions and sequestration for wood products

• Wood products can control greenhouse gas carbon emissions in three ways:

  • Capture atmospheric carbon dioxide in growing trees, harvest the trees, and put the wood into buildings

  • Reduce carbon emissions by using wood instead of concrete and steel

  • Reduce carbon emissions by using biofuels instead of fossil fuels in manufacturing wood products

Green roofs and natural building materials

• Growing interest in incorporating natural organic materials into building design

• Benefits of wood materials for saving embodied energy and sequestering carbon

• Thermal mass benefits of rammed earth and adobe structures

• Growing interest in straw bale-walled buildings for thermal insulation and affordability

• Green roofs have a growing market, especially in urban multifamily residential, commercial, and industrial buildings

• Green roofs provide various benefits such as reduced heating and cooling costs, reduced runoff volume, extended roof life, improved building appearance, reduced heat island effect, improved local air quality, and increased recreational benefits

Page 24

Green roof installations

• Green roof installations increased from less than 1 million square feet per year in 2004 to more than 20 million square feet per year in 2012, 2013, and 2014

• Cities like Washington (DC), Chicago, Portland (OR), Philadelphia, Seattle, and others have embraced green roofs because of the community benefits

Tools for embodied energy and life-cycle analysis of buildings

• Analyzing embodied energy and life-cycle energy and environmental costs is improving

• Methods include better models, conceptual approaches, data, and techniques/software for analysis

• Two methods worth mentioning:

  • Athena Sustainable Materials Institute's Impact Estimator for Buildings

  • National Institute for Standards and Technology (NIST) BEES software

Page 25

Green building ratings

• Green buildings aim to maximize environmental and economic benefits, reduce impacts, and improve livability, health, and productivity

• Energy use has the greatest influence on these objectives

• Green building embraces five strategies:

  • The site: Land use, site planning, stormwater management, landscaping, and ecosystem protection

  • Energy use: Greater efficiency and use of renewable energy

  • Water conservation: Efficiency of plumbing fixtures, irrigation, and rainwater collection

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• Green Building movement is largely voluntary and goes beyond minimum standards

  • Provides consumers with confidence about the buildings they occupy and the homes they buy or rent

  • Provides builders and designers accepted criteria and certification to market their buildings and services

• Market for Green Buildings is expanding

  • 40%–48% of new nonresidential construction in the U.S. was green in 2015

  • 53% of firms in the U.S. report that more than 60% of their building work is green

  • Green construction spending is forecast to grow 15% per year to $224 billion from 2015 to 2018

  • LEED, the largest Green Building program, had 52,000 certified projects comprising 5 billion square feet of construction space in all 50 states and 150 countries by 2015

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EPA's ENERGY STAR Homes and DOE's Zero Energy Ready Homes

• ENERGY STAR homes and ZERH focus on home energy performance, building envelope, and appliance efficiency

• Both require verification and field testing by RESNET-certified auditors

• ENERGY STAR homes go beyond IECC code compliance and specify more efficient lighting, appliances, faucets, toilets, and shower heads

• EPA estimates that 1.6 million ENERGY STAR certified homes have been built since 1986, saving 30% compared to typical homes built to code and $4.7 billion in utility bills

• DOE's Builders Challenge program started in 2008 and was renamed Zero Energy Ready Home

• ZERH has requirements similar to ENERGY STAR and has both prescriptive and performance compliance pathways

USGBC's LEED Certification Program

• LEED is the largest Green Building certification program

• Different flavors of LEED for various types of buildings and spaces

  • LEED for Building Design + Construction (BD+C)

  • LEED for Building Operations + Maintenance (BO+M)

  • LEED for Interior Design + Construction (ID+C)

  • LEED for Homes (H)

  • LEED for Neighborhood Development (ND)

• LEED process requires registration, evaluation against checklists, and accumulation of points for certification levels (certified, silver, gold, platinum)

• Major categories on the project checklist for LEED for BD+C include Energy and Atmosphere, Indoor Environmental Quality, Location and Transportation, Materials and Resources, Water Efficiency, and Sustainable Sites

• LEED for BD+C Homes has a slightly different weighting of categories compared to basic BD+C

• Several measures are prerequisites with no points, such as meeting ENERGY STAR for Homes certification criteria

• Examples of LEED BD+C platinum-certified buildings are provided in Sidebar 8.5

Page 28: Passive House, PHIUS+, and DOE ZERH Standards

• "Passive House" originated in the U.S. in the 1970s and 1980s as a movement to apply superinsulation and passive solar heating to new housing.

• The concept of superinsulation was researched in Europe in the late 1980s and early 1990s.

• In 1996, Wolfgang Heist founded the Passive House Institute (PHI) in Darmstadt, Germany.

• The PHI developed voluntary performance standards for PassivHaus certification.

  • Annual heating and cooling energy demand should not exceed 15 kWh/m2 per year or a peak heat load of 10 W/m2.

  • Total primary source energy for heating, hot water, and electricity should not exceed 120 kWh/m2 per year.

  • Infiltration air leakage should not exceed 0.6 ACH50 as tested by blower door.

• By 2010, over 25,000 PassivHaus buildings were built in Europe, mostly in Germany, Austria, and Sweden.

• The Passive House Institute US (PHIUS) was established in the U.S. in 2007 to promote PH research, training, certification, and outreach.

• PHIUS has trained over 1800 professional certifiers.

• The number of PHIUS-certified buildings has been growing quickly, from 15 in 2010 to 225 in 2015.

• There were some problems with the adoption of PH standards in the U.S. due to differences in climate and energy prices.

• In 2012, the U.S. DOE joined forces with PHIUS to promote the DOE's Challenge Home program, now the ZERH program, along with PHIUS+ certification.

• A 2015 study validated U.S. climate-specific passive standards that retain ambitious energy reduction targets that are economically feasible.

• The study used NREL's Building Energy Optimization software (BEopt) to cost-optimize energy-saving upgrade packages for 110 climate locations in North America.

Page 29: Whole Building to Zero Net Energy

• The study resulted in the PHIUS+ 2015 standard.

• The annual heating and cooling energy demand was changed to climate- and location-specific mandatory thresholds aimed at a near-optimal "sweet spot."

• Point 1 reference building has no added efficiency upgrades beyond code, higher utility bills, but no added finance cost for upgrades.

• Point 4 building is zero energy and has no utility bill but higher mortgage finance for upgrades.

• Point 2 building has a cost-optimal set of upgrades.

• At point 3, PV generation becomes more cost-effective than efficiency.

• LEED v4 for BD+C: New Construction and Major Renovation Project Checklist includes various categories such as Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Material and Resources, Indoor Environmental Quality, Innovation, and Regional Priority.

• LEED v4 for Building Design and Construction: Homes and Multifamily Lowrise Project Checklist includes categories such as Integrative Process, Location and Transportation, Sustainable Sites, Water Efficiency, Energy and Atmosphere, Material and Resources, Indoor Environmental Quality, Innovation, and Regional Priority.

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• LEED BD+C Platinum Projects:

  • Stony Brook Millstone Watershed Associates, Hopewell, NJ:

    • Environmental center on 84-acre preserve

    • Close to zero net energy with solar PV and ground-source heat pump

  • Hillman Hall, Brown School, Washington University, St. Louis, MO:

    • Infill development integrating two existing buildings

    • Achieved 42% energy savings with energy efficiency and solar PV

  • P-060 Wounded Warrior Hope & Care Center, Camp Pendleton, CA:

    • State-of-the-art rehabilitation center for injured service members

  • Blacksburg Motor Company, Blacksburg, VA:

    • Renovation project by the Town of Blacksburg

    • Converted a brownfield site to a functional town office building

    • Energy savings from a ground-source heat pump and efficient design

• LEED Scorecards for Project Examples:

  • Categories: Sustainable sites, Water efficiency, Energy and atmosphere, Materials and resources, Indoor air quality, Innovation, Regional priority

  • Ratings and certifications for each project

Page 31:

• Whole Building to Zero Net Energy:

  • Transition to zero net energy (ZNE)

  • Goals and changes in energy consumption and efficiency standards

  • Three steps to achieve zero energy

• EarthCraft Certification Program:

  • Similar to LEED, developed in Atlanta in 1999

  • Used in six southeastern states

  • Criteria include energy and water efficiency, stormwater management, sustainable materials, etc.

  • Different programs for various applications

• EarthCraft net zero homes in Virginia:

  • Eight-unit affordable senior housing development in Blacksburg

  • All-electric duplexes with high energy efficiency standards

  • High-efficiency mini-split heat pumps and 30 kW of solar PV

  • Certified zero net energy

Page 32:

• Zero Net Energy Buildings (ZNEBs):

  • Rapid development of ZNEBs

  • ZNE concept and definitions

  • Steps to achieve ZNEBs: reduce energy loads, use high-efficiency systems, smart energy management, energy recovery systems

• EarthCraft-House Criteria and Scoring:

  • Major categories and selected criteria for EarthCraft-House certification

  • Scoring system for certification levels (Certified, Gold, Platinum)

Page 33:

• Whole Building to Zero Net Energy

• Use distributed energy resources to meet and balance remaining building energy loads

  • Rooftop solar PV

  • Solar water heaters

  • Energy storage

  • Microturbines

• Monitor and manage building loads postoccupancy

  • Monitoring systems

  • Occupant engagement

• ZNEBs expected to grow rapidly after 2020

• California's Title 24 code mandates all new residential buildings be ZNE

• ZNE homes in California expected to grow from 140 in 2015 to 150,000 in 2020

• California's ZNE Action Plan has a voluntary action component to initiate ZNE units up to 31,000 per year by 2019

• Experience gained in California combined with more stringent IECC and ASHRAE standards and improved solar PV and storage technologies

Page 34:

• Greater energy efficiency in buildings undergoing progress due to new technologies, designs, and building practices

• Improved cost-effectiveness

• More stringent building and equipment standards reflecting new cost-effective technology

• Green Building rating systems increase information for consumers and builders

• Appliance and equipment efficiency spurred by federal efficiency standards

• HVAC equipment, refrigerators, washing machines, dishwashers, water heaters, motors, and pumps have efficiency standards

• Refrigerators sold today use one-third the energy compared to those sold in the late 1980s

• LED lighting systems experiencing a revolution and estimated to save consumers $40 billion per year in utility bills by 2030

• New building energy efficiency codes continue to improve

• Residential homes built to the IECC 2015 consume 60% less energy compared to buildings built to code in the mid-1980s

• Commercial buildings built to 2013 ASHRAE 90.1 use 53% less energy

• California has the most stringent building energy efficiency code, aiming for ZNE for all new residential housing by 2020 and all new commercial buildings by 2030

• Green Buildings address human health and environmental impact, including water, waste, site impacts, and indoor air quality

• 40%-48% of new nonresidential building construction in 2015 was green

• Green Building rating systems popular among consumers and builders

• Whole building energy efficiency is an integral component of the movement toward whole community energy efficiency

Page 35:

• Properly sited, thermally and electrically efficient buildings with on-sit