Making The Case For Green
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Making The Case For Green

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Paul Marquis, the education coordinator for NEXUS Green Building Resource Center, discusses green-building economics, life-cycle costing and total cost of ownership, and rebate and incentive programs ...

Paul Marquis, the education coordinator for NEXUS Green Building Resource Center, discusses green-building economics, life-cycle costing and total cost of ownership, and rebate and incentive programs available to homeowners.

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    Making The Case For Green Making The Case For Green Presentation Transcript

    • The Green Roundtable and Making the Case for Green- Basic economics The Green Roundtable (copyright © Green Roundtable 2007)
    • Green Roundtable Consulting, education, training and strategic planning to create healthy environments by integrating principles of sustainability into mainstream planning, design and construction. The Green Roundtable (copyright © Green Roundtable 2007)
    • Objectives Answer the following questions: - Why do green? - What are the key value-added propositions in green building? – i.e. selling green - What are the basic economics of green building? - How can we financially justify green? - How can we sweeten the pot for our clients? The Green Roundtable (copyright © Green Roundtable 2007)
    • Why do green…. 4 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sad realities…. Even if you don’t believe that the global warming threat is real, we are facing these certain realities: • Ozone depletion • Air & water pollution • Destruction of worlds forests & green spaces • Species & biodiversity loss • Acid rain • Collapse of world’s fisheries • Fresh water scarcity • Topsoil loss; Soil contamination 5 The Green Roundtable (copyright © Green Roundtable 2007)
    • And if global warming is real… • Crop failure on a massive scale • Increases in drought frequency • Deadly heat waves • Rising sea levels/ coastal flooding • Increased frequency & duration of storm activity • Expansion of desert areas • Increases in disease vectors 6 The Green Roundtable (copyright © Green Roundtable 2007)
    • On a more local or personal level… • Rapidly rising energy costs • Escalating prices on consumer goods • Blackouts/ brownouts • Water shortages • Supply chain interruptions • More frequent economic losses due to increased storm intensity & flooding 7 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… The United States produces 25% of global greenhouse gas emissions. Americans produce twice as much per person than other industrialized nations 8 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… Water tables are now falling in countries that contain over half the world’s people 9 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… There are currently 1,243 EPA Superfund sites on the National Priorities List and 60 more proposed (as of 3/20/07) The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… The incidence of asthma has increased dramatically over the last 25 years in the U.S. and other industrialized nations. 11 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… The EPA estimates that indoor air can be up to five times as contaminated with VOCs as outside air. 12 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… The EPA also reports that the airborne contaminants found in our homes are three times more likely to cause cancer than the pollutants outside The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… Cancer clusters have been identified in some more-affluent communities and have been attributed to chemically-intensive landscape management practices 14 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… A 15-year study in Oregon concluded that women who work in the home have a 54% higher death rate from cancer than women who work outside the home The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… China recently caught up to the United States in terms of overall energy consumption. India isn’t far behind. The U.S. & Canada are still the per capita leaders by far 16 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some sobering facts… The U.S., with 5% of the worlds population, consumes more than a third of it’s resources and over a quarter of its energy resources. 17 The Green Roundtable (copyright © Green Roundtable 2007)
    • Where do buildings fit in… Half of U.S. greenhouse gas emissions come from buildings (construction/ operation) Buildings account for nearly half of the total energy use in the United States Buildings represent the single largest energy consumer in the U.S., followed by the transportation sector 18 The Green Roundtable (copyright © Green Roundtable 2007)
    • 19 The Green Roundtable (copyright © Green Roundtable 2007)
    • Additional housing sector facts… According to HUD, if Americans can reduce home energy use by 10% over the next ten years (a doable number!), it will be the energy equivalent of 40 new power plants (600 Mw) and the greenhouse gas equivalent of 25 million vehicles The Green Roundtable (copyright © Green Roundtable 2007)
    • Additional housing sector facts… There are more than 76 million residential buildings in the USA today Estimates of residential energy consumption as a proportion of the nation’s total energy load range from around 20 – 40% From 2000 to 2005, winter heating costs for natural gas increased by 115%, oil by 135%, and electricity by 18% The Green Roundtable (copyright © Green Roundtable 2007)
    • Food for thought…. 22 The Green Roundtable (copyright © Green Roundtable 2007)
    • 23 The Green Roundtable (copyright © Green Roundtable 2007)
    • Perhaps the most sobering fact of all… It has been estimated that in order for the current population of the Earth to live at the same quality of life as the industrialized nations, it would require the resources of four ‘Earth equivalents’. 24 The Green Roundtable (copyright © Green Roundtable 2007)
    • This we know… We live on a planet of finite natural resources We are currently using those resources at an unsustainable rate As a nation, the United States uses a disproportionate share of the world’s natural resources 25 The Green Roundtable (copyright © Green Roundtable 2007)
    • This we know… Energy prices are likely to trend in only one direction for the foreseeable future! Most other resource prices are likely to follow the same trend These conclusions are rooted in simple physics, chemistry, biology and economics 26 The Green Roundtable (copyright © Green Roundtable 2007)
    • A solution: Green Building 27 The Green Roundtable (copyright © Green Roundtable 2007)
    • Why build green? Building green: • Reduces the ecological footprint of the building • Creates a safer and healthier indoor environment • Saves on utility expenses • May improve property resale value • May increase affordability • Typically results in a more durable, maintenance- free building • Provides security/ passive survivability • Reduces our dependence on foreign oil The Green Roundtable (copyright © Green Roundtable 2007)
    • The three prime movers (in order): • Economics- Reducing energy cost/ protecting the bottom line • Health- Maintaining a safe and healthy environment for one’s family & oneself • Personal impact- Addressing the greater good- minimizing environmental footprint 29 The Green Roundtable (copyright © Green Roundtable 2007)
    • Some other motivators: • The cool factor • The “shiny metal objects” mentality • Peer pressure 30 The Green Roundtable (copyright © Green Roundtable 2007)
    • Defining green building: The effective and responsible integration of the built environment into the natural world to protect natural resources and ensure healthy and comfortable indoor environments 31 The Green Roundtable (copyright © Green Roundtable 2007)
    • What makes it green? • Low embodied energy (entire lifecycle) • Minimizes impact on wildlife habitat, green space, waterways, etc • Minimizes depletion of natural resources • Poses minimal harm to humans during its manufacture, transport, installation, end-use or disposal The Green Roundtable (copyright © Green Roundtable 2007)
    • What is embodied energy? The quantity of energy required to manufacture, and supply to the point of use including: • Extraction • Assembly • Transportation • Installation • Manufacturing • Some definitions also include: Disassembly & Removal The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • The LEED Credit Categories Sustainable Sites Water Efficiency Energy & Atmosphere Materials & Resources Indoor Environmental Quality Innovation & Design Process The Green Roundtable (copyright © Green Roundtable 2007)
    • Cornerstones of green building (structure itself) Site Site Site Site 36 The Green Roundtable (copyright © Green Roundtable 2007)
    • How green is it? • The “no-build” option is always the greenest way • Smaller is greener • More efficient material resources use is better • The more durable (in use) & maintenance free the better The Green Roundtable (copyright © Green Roundtable 2007)
    • Selection criteria: Materials • Efficiently uses energy & resources • Derived from rapidly renewable resources • Contains high recycled material content • Can be reused/ recycled at the end of it’s useful life • Can be down-cycled at the end of it’s useful life • Biodegradable The Green Roundtable (copyright © Green Roundtable 2007)
    • Recycled Content Post-Consumer vs. Pre-Consumer aka Post-Industrial The Green Roundtable (copyright © Green Roundtable 2007)
    • Defining green: Design resources • Building America- http://www.eere.energy.gov/buildings/building_america/ about.html • Environmental Building News/ Greenspec- http://www.buildinggreen.com) •http://www.austinenergy.com/Energy%20Efficiency/Progr ams/Green%20Building/Sourcebook/index.htm The Green Roundtable (copyright © Green Roundtable 2007)
    • Measuring Green:Rating Systems • Energy Star Homes- www.energystar.gov • HERS (http://www.energy.ca.gov/HERS) • International Energy Conservation Code (IEEC)- http://www.iccsafe.org/ • LEED - www.usgbc.org The Green Roundtable (copyright © Green Roundtable 2007)
    • General strategies: • Minimize impact on building sites/ area • Incorporate energy efficient design details • Create a high-performance building envelope • Use energy-efficient lighting, equipment & appliances • Employ water conservation strategies • Employ natural daylighting techniques • Create comfortable & healthy indoor environments 42 The Green Roundtable (copyright © Green Roundtable 2007)
    • Economics of green building The Green Roundtable (copyright © Green Roundtable 2007)
    • Economic realities Up front costs or first-costs of green building are often greater than conventional building That doesn’t need to be the case! The Green Roundtable (copyright © Green Roundtable 2007)
    • Additional construction costs The Green Roundtable (copyright © Green Roundtable 2007)
    • Additional Pitfalls • Uninformed & resistant code and municipal officials • Products that ‘go away’ • Sourcing materials • “Greening” small-scale projects The Green Roundtable (copyright © Green Roundtable 2007)
    • Keys to success • Careful design • Early planning • Using a team approach between owners, design professionals and code officials, and bringing everybody together early in the process The Green Roundtable (copyright © Green Roundtable 2007)
    • Architects Product Federal, Manufacturers Building Local, Owners and State Governments Nonprofit Planners Leaders Engineers Interior Financial Utility Designers Planners Landscape Managers Architects Building Tenants Property Code The Green Roundtable (copyright © Green Roundtable 2007) Managers Officials
    • Managing up-front costs (& expectations!) • Start planning and design as early as possible • Adopt a systems approach during the design phase- understand that virtually all systems/ components affect the others • Design carefully and then finalize your design as early in the process as possible- change orders can be expensive! • Make sure that you understand the properties of the materials and how to use them! Do your homework • Determine ‘lead time’ on products as early as possible- this may allow some flexibility in shipping, will minimize project delays, etc. The Green Roundtable (copyright © Green Roundtable 2007)
    • Managing up-front costs, continued • Right-size systems- Don’t use rule of thumb approaches • Use a trade-off approach- offset increased cost in one product or system through savings in another • Go green by incorporating no-cost design features and elements– The Low-hanging Fruit • Offset increased first cost with rebates & incentives • Match the project scale to the genuine space needs of the client! The Green Roundtable (copyright © Green Roundtable 2007)
    • Underlying all: Scale Scale Scale The Green Roundtable (copyright © Green Roundtable 2007)
    • Consider this: The average size of a U.S. single-family house has increased by 33% since 1975. At the same time average family size has decreased. The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Managing up-front costs, continued • Take advantage of marginal cost of installing higher quality materials- e.g. adding thicker insulation (reduces life-cycle cost, but maybe not up front cost) The Green Roundtable (copyright © Green Roundtable 2007)
    • Justifying increased up-front costs Making the case for reduced Life-Cycle Cost or Total Cost of Ownership (TCO): • Green buildings usually use less energy to operate than their conventional counterparts • Green buildings are typically more durable & maintenance-free due to the application of sound principles of building science • There are typically additional benefits that help to warrant the increased cost The Green Roundtable (copyright © Green Roundtable 2007)
    • The trump card A University of Michigan study demonstrated that greater than 90% of the embodied energy in a home is attributable to operating energy Reduce operating energy and potentially reduce TCO significantly The Green Roundtable (copyright © Green Roundtable 2007)
    • Low-hanging Fruit (A sampling) The Green Roundtable (copyright © Green Roundtable 2007)
    • Using the site • Take advantage of existing vegetation if possible- deciduous trees for shading; coniferous trees as wind breaks • Site structure on south-facing slope for maximum solar gain; take advantage of wind & solar resources • Use natural terrain features to protect structure from cold winter winds • Site structure downwind from lakes, ponds, wetlands for natural cooling • Take advantage of hills that funnel breezes • Use earth-berming if topography permits The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Building orientation/ layout • Orient structure along East-West axis; i.e. long side facing south • Minimize glazing area on north, northeast & west- facing walls • Maximize glazing on south-facing walls to maximize winter solar gains • Incorporate buffer spaces in structure- closets along outside walls, vestibules, enclosed porches, etc. • Minimize surface area-to-volume ratio; avoid complicated designs w/ many intersecting planes The Green Roundtable (copyright © Green Roundtable 2007)
    • Sustainable sites: Low-hanging fruit • Minimize heat urban island effect by using light- colored pavement • Manage stormwater by using pervious paving • Use landscape features that allow stormwater to percolate into soil- e.g. bioswales • Use water conserving landscape maintenance practices– Xeriscaping, native plantings, etc. • In general, minimize site disturbance The Green Roundtable (copyright © Green Roundtable 2007)
    • Low-water trees: Common name Botanical Name Height Amur Maple Acer ginnala 20'-25' Austrian Pine Pinus nigra 50' Japanese Black Pine Pinus thunbergii 6-10' Cornelian Cherry Cornus Mas 20-25' London Plane Platanus x acerifolia 50' White Oak Quercus alba 50' The Green Roundtable (copyright © Green Roundtable 2007)
    • Low-water shrubs: Common name Botanical Name Height Broom Cytisus scoparius 5-6' Flowering Quince Chaenomeles specoisa 6'-10' Junipers Juniperus sp. 2'-9' Cinquefoil Potentilla 3'-4' Butterfly Bush Buddleia davidii 6-10' Rose-of-Sharon Hibiscus syriacus Diana 6-8' Winterberry Ilex verticillata 8-10' Mugo Pine(dwarf) Pinus mugo 3-4' The Green Roundtable (copyright © Green Roundtable 2007)
    • Low-water groundcovers: Common name Botanical Name Height Bearberry Arctostaphylos uva-ursi 6-8" Creeping Lilly-turf Liriope spicata 6-8" Violets Viola sp.. 6-8" Snow-in-Summer Cerastium tomentosum 6-8" The Green Roundtable (copyright © Green Roundtable 2007)
    • Low-water perennials: Common name Botanical Name Height New England Aster Aster Novae-angliae 15-30" CommonBlanketflower Gaillardia aristata 24-36" Moonbeam Coreopsis verticillata 24-36" Purple Coneflower Echinacea purpurea 24-36" The Green Roundtable (copyright © Green Roundtable 2007)
    • Materials: Low-hanging fruit • Employ advanced framing techniques • Use structure as finish • Keep it small! • Use salvaged/ surplus materials • Use low-VOC paints, sealants & adhesives The Green Roundtable (copyright © Green Roundtable 2007)
    • Design strategies: Advanced Framing • Improves thermal envelope of building– more places to insulate! • Saves on framing lumber expense • Reduces lumber disposal cost/ impact • Saves on labor cost since fewer “sticks” installed • Savings estimates range to 20% of overall framing expense • Can offset the cost of using FSC-certified lumber The Green Roundtable (copyright © Green Roundtable 2007)
    • Advanced framing & efficiency • Provides more room for insulation! • Reduces bridging heat loss The Green Roundtable (copyright © Green Roundtable 2007)
    • Advanced Framing • Features 2 x 6 studs on 24” centers • Single top plate if trusses/ roof rafters placed directly over wall studs • Jack studs eliminated at window openings • “Right-sized” headers; insulated, engineered headers • No headers in non-load bearing partitions • Open corner framing (2-stud corners) • Ladders at T-intersections The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
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    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Durability: Low-hanging fruit • Minimize roof penetrations • Incorporate overhanging roofs • Maintain proper grading & ground clearances • Keep vegetation away from structure • Use well-designed wall sections The Green Roundtable (copyright © Green Roundtable 2007)
    • Energy: Low-hanging fruit • Right-size systems • Move ductwork into conditioned space • Use zoned heating • Use structured plumbing & PEX piping • Spec Energy Star • Use zone lighting • Use natural daylighting strategies The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Cooling Use ceiling fans w/ cathedral or high ceilings to eliminate temperature stratification (both heating and cooling season) Locate AC/ heat pump condensers on N or NE or NW side out of direct sun! Shade air conditioner and heat pump condensers w/ vegetation or artificial shading (be careful w/ deciduous vegetation) if you have to locate on sunny side The Green Roundtable (copyright © Green Roundtable 2007)
    • Cooling Install awnings, overhangs and other shading structures, such as pergolas Make sure attic space is well vented Use deciduous vegetation on south, SW and west sides of structure for summer shading; use vines on trellises too Use coniferous (evergreen) trees/ shrubs to redirect breezes/ wind The Green Roundtable (copyright © Green Roundtable 2007)
    • Cooling Take advantage of prevailing winds for natural cooling Maximize cross-ventilation Use building elements to funnel winds (e.g. casement windows) Use light-colored shingles or roof membrane on very low pitched or flat roofs The Green Roundtable (copyright © Green Roundtable 2007)
    • A sampling of strategies & approaches for reducing life- cycle cost or TCO 79 The Green Roundtable (copyright © Green Roundtable 2007)
    • Green Practice: Water conservation The Green Roundtable (copyright © Green Roundtable 2007)
    • MWRA A water conservation resource Order a free water saving kit at: www.mwra.com/04water/html/watsense.htm The Green Roundtable (copyright © Green Roundtable 2007)
    • Water conservation • Use low-flow showerheads & faucet aerators • Incorporate graywater systems • Use demand pumps in supply system • Use dual-flush or composting toilets; waterless urinals • Collect rainwater in rain barrels for landscape irrigation The Green Roundtable (copyright © Green Roundtable 2007)
    • 83 The Green Roundtable (copyright © Green Roundtable 2007)
    • Coroma Dual-Flush Toilet Source The Portland Group- Splash Showroom 244 Needham St. Newton, MA 02164 617.332.6662 See: http://www.caromausa.com/products/toilets.htm The Green Roundtable (copyright © Green Roundtable 2007)
    • Green Systems: Gray water The Green Roundtable (copyright © Green Roundtable 2007)
    • Gray water • Collected from drain-waste-vent system other than toilets & kitchen sinks with garbage diposals (“Black water”) • Generally used for flushing toilets, landscape irrigation & other non-potable, utility purposes • May be difficult to get local code approval The Green Roundtable (copyright © Green Roundtable 2007)
    • Gray water: A direct approach http://www.gaiam.com/product/eco-home-outdoor/energy-efficient- climate-control/energy-saving-tools/toilet+lid+sink.do The Green Roundtable (copyright © Green Roundtable 2007)
    • Rainwater collection • For 1000 sq ft roof area, 15 – 25,000 gallons of rainwater can be collected annually in Eastern states • Combined with drip-irrigation systems, collected rainwater can keep landscaping vibrant even during drought conditions • Using rainwater helps to maintain aquifers and public water supplies at adequate levels • Rainwater does not contain chlorine so it is better for plants, garden ponds, etc. • Rainwater does not contain minerals, so it is potentially better for use as laundry/ wash water • Rainwater is free, and inexpensive to collect & store! The Green Roundtable (copyright © Green Roundtable 2007)
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    • http://www.cleanairgardening.com/33galrainbar.html The Green Roundtable (copyright © Green Roundtable 2007)
    • Xeriscaping (low-water-landscaping) • Two major aspects: -Making maximum use of available precipitation -Selecting species with low water requirements • Use mulches • Create water retention landscape features • Use drip irrigation & soaker hoses • Group plants • Use plantings to create windbreaks & shade to protect from drying winds and sun • Use native plantings, they are better suited to natural rainfall patterns The Green Roundtable (copyright © Green Roundtable 2007)
    • Drip emitters The Green Roundtable (copyright © Green Roundtable 2007)
    • Soaker Hose The Green Roundtable (copyright © Green Roundtable 2007)
    • Energy Conserving Design Strategies (a sampling) The Green Roundtable (copyright © Green Roundtable 2007)
    • Design Strategies: Thermal mass Thermal mass: • Can be used to store heat in winter • Can help to moderate temperatures year-round • Key element in passive solar design The Green Roundtable (copyright © Green Roundtable 2007)
    • Thermal mass: How to incorporate • Masonry veneers on exterior walls • Masonry finishes on interior walls & floors • Fireplaces, chimneys & interior masonry features • Thickened walls- e.g.double drywall layer • Cob & masonry construction • Green roofs • Water features/ elements The Green Roundtable (copyright © Green Roundtable 2007)
    • Thermal mass: additional benefits • Acoustic comfort • Increased structural integrity in some situations The Green Roundtable (copyright © Green Roundtable 2007)
    • Design Strategies: Green roofs • Properly designed, can pay for themselves in 10 – 15 years via reduced energy cost • Especially effective in reducing cooling costs • By some estimates, can reduce cooling costs by up to 30% in single-story structures The Green Roundtable (copyright © Green Roundtable 2007)
    • Green roofs: additional benefits • Can provide stormwater management • Reduce urban heat islands • Help to minimize global warming • May extend the life of your roof • Provides green space & wildlife habitat • Improves acoustic comfort The Green Roundtable (copyright © Green Roundtable 2007)
    • Design Strategies: Passive solar The Green Roundtable (copyright © Green Roundtable 2007)
    • Passive solar Free heat from the sun; ‘greenhouse effect’ (good kind!); good southern exposure/ solar aperture needed Basic requirements: • Collect it… • Store it… • Retain it… • Distribute it… The Green Roundtable (copyright © Green Roundtable 2007)
    • 5 Major elements of Passive Solar • Aperture/ Collector (glazing) • Absorber • Thermal storage (mass) • Distribution • Control The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Requirements • Glazing area to collect sunlight- 7% rule- So.-facing • Thermal mass- needed to store heat if net window area is more than 7% of total floor area • Window insulating system (and good building envelope insulation) to keep heat in at night • Shading—vegetation (deciduous), or shading structures like awnings, roof overhangs and pergolas, to prevent overheating during warmer mos. The Green Roundtable (copyright © Green Roundtable 2007)
    • Requirements,cont. • Distribution system—to remove excess heat to other parts of house where it may be needed in winter • Ventilation system—to remove excess heat to outside during warm weather The Green Roundtable (copyright © Green Roundtable 2007)
    • Passive Solar Rules-of-Thumb • Orientation of aperture area should be within 30 degrees of true south • Aperture should ideally be shade-free from 9am – 3pm • South-facing glass should be vertical and should have some kind of overhanging to shade from summer sun • Direct gain systems are most common and easiest to integrate into most designs; glazing should not exceed 12% of building floor area • Thermal mass can help to moderate temperature in summer as well as store heat in winter The Green Roundtable (copyright © Green Roundtable 2007)
    • Passive Solar Rules-of-Thumb • In sunspaces, may need powered ventilation to minimize summer overheating • Skylights should be avoided on all but north and northeast-facing roof surfaces, as they can otherwise contribute to overheating in the summer, and won’t provide appreciable gains in the winter due to low angle of sun • Deciduous trees can provide good summer shading, but should not be located too close to house/ sunspace, as trunk/ branches may provide too much shade in winter • Well designed passive solar can provide 5 –25% of space heating needs with no added cost The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Angled glass may not be the best configuration, especially without an overhang! The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Skylights may contribute to summer overheating and winter heat loss. The Green Roundtable (copyright © Green Roundtable 2007)
    • Frost-protected Shallow Foundations • Improves thermal performance • Reduce excavating expense • Reduce material expense • Reduce site impact • Note: Local code officials may be resistant to approving this foundation system The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Design Strategies: Natural daylighting • Can reduce lighting loads and cooling loads • Improves indoor environmental quality • Residential systems typically consist of skylights, clerestory windows or tubular daylighting devices (TDD’s; “sun tubes” or “light tubes”) The Green Roundtable (copyright © Green Roundtable 2007)
    • Design Strategies: Natural daylighting • Skylights in south, southwest and west-facing roofs can contribute to summer overheating • Skylights in more north-facing roof surfaces can contribute more light on cloudy days • TDDs may contribute less to overheating The Green Roundtable (copyright © Green Roundtable 2007)
    • Sky tube (TDD) The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Natural daylighting • Light-colored walls reflect light deeper into structure • Light shelves can serve the same purpose, and accomplish this w/o excessive glare; they provide shading as well • Wide windowsills/ shelves can reflect light as well, but may contribute to glare • Combine daylighting strategies with photo-resistor controlled lights to avoid excessive lighting during daytime • Landscape features can be utilized for reflecting light into interior as well (paved surfaces, water features, etc) The Green Roundtable (copyright © Green Roundtable 2007)
    • Light shelves shade window while providing natural daylight via light reflected from top surface Can help light to penetrate deeper into structure The Green Roundtable (copyright © Green Roundtable 2007)
    • The Green Roundtable (copyright © Green Roundtable 2007)
    • Suggested Room Surface Reflectances: Ceilings: > 80% Walls: 50%-70% Floors: 20%-40% Furnishings: 25%-45% The Green Roundtable (copyright © Green Roundtable 2007)
    • Lighting & Daylighting Analysis RADIANCE is a lighting and daylighting visualization tool developed by LBNL and is available over the web: http://radsite.lbl.gov/radiance/ The Green Roundtable (copyright © Green Roundtable 2007)
    • Green Practice: Improving the Building Envelope The Green Roundtable (copyright © Green Roundtable 2007)
    • Building envelope, definition All of the elements of a building that separate and isolate the outdoor environment from the indoor environment. This may include walls and wall finishes, roofs and roof finishes, doors, windows, skylights and basement floors and walls. The Green Roundtable (copyright © Green Roundtable 2007)
    • Key Principle- Saving home energy As a general rule, for the average home/ homeowner, the greatest energy savings will be achieved through managing the demand side of the equation, rather than the supply side. In other words, you’ll get better bang for your buck through energy conservation measures, like insulating & minimizing air infiltration, than incorporating expensive renewable energy systems such as wind and solar. The Green Roundtable (copyright © Green Roundtable 2007)
    • An exception: Exceptions to this may include passive solar, and situations where you qualify for a substantial rebate and/or credit for other renewable energy systems (keep in mind the embodied energy of systems though!) There are other compelling reasons to perform upgrades like this, such as reduced reliance on foreign energy resources, promotion of renewable energy & local industry, passive survivability, etc. The Green Roundtable (copyright © Green Roundtable 2007)
    • Preventing heat loss • Insulate • Air seal (prevent infiltration) • Use landscape features- vegetative shields, etc. • Address lifestyle issues • Best bang for buck through air sealing! Begin here! The Green Roundtable (copyright © Green Roundtable 2007)
    • Building envelope, functions • Protect structural elements and interior of structure from weather, esp. moisture • Help to maintain proper thermal regime within structure • Help to maintain proper humidity regime within structure • Prevent infiltration of outside air and contaminants • Acoustically isolate interior of structure from outside noise • In essence, act as ‘membrane’ for the structure The Green Roundtable (copyright © Green Roundtable 2007)
    • Building envelope failure • Air leaks leading to: -Infiltration of unconditioned air/ Drafts -Direct escape of conditioned air to outside -Infiltration of outdoor contaminants • Excessive accumulation of interior moisture in wall cavities causing structural/ insulation failure & mold • Excessive heat transfer from inside to outside • External water leaks leading to: -Damaged structural elements -Damaged interior finishes -Insulation failure -Damaged interior furnishings and appliances -Mold problems The Green Roundtable (copyright © Green Roundtable 2007)
    • Building envelope components • Exterior finish- wood siding, vinyl siding, brick, etc. • Weather membrane/ air barrier/ drainage plane- building paper, Tyvek, Typar, etc. • Exterior sheathing- usually plywood or OSB • Wall/ ceiling cavities (inc. structural members & insulation) • Vapor retarders/ barriers • Doors & windows • Interior wall finish The Green Roundtable (copyright © Green Roundtable 2007)
    • Codes and standards • Sixth edition of MA building code was officially superseded by 7th edition as of January 1st, 2008 • New MA energy code based on 2006 International Energy Conservation Code; more stringent • Better to follow Energy Star Homes or HERS guidelines for maximum energy efficiency and code compliance (see resources slide) The Green Roundtable (copyright © Green Roundtable 2007)
    • Minimizing air infiltration (sealing building envelope) • Min .35 Air changes per hour (ACH) for good ventilation; max .50 for energy efficiency (Energy Star) • Seal obvious openings- pipe penetrations, attic scuttles, electrical receptacles, recessed lights, etc. • Openings to attic spaces are some of worst offenders • Any place where two building planes meet is good candidate for air sealing • For additions/ new construction, use exterior air barrier to minimize infiltration The Green Roundtable (copyright © Green Roundtable 2007)
    • Housewrap to minimize air infiltration & protect from moisture The Green Roundtable (copyright © Green Roundtable 2007)
    • Blower door test to measure air leakage The Green Roundtable (copyright © Green Roundtable 2007)
    • Air leakage pathways The Green Roundtable (copyright © Green Roundtable 2007)
    • Air leakage proportion through various pathways The Green Roundtable (copyright © Green Roundtable 2007)
    • Attic hatches/ scuttles are a major leakage pathway The Green Roundtable (copyright © Green Roundtable 2007)
    • A commercial solution for attic openings See also www.efi.org The Green Roundtable (copyright © Green Roundtable 2007)
    • Insulate header/ rim joists w/ rigid foam & expanding foam The Green Roundtable (copyright © Green Roundtable 2007)
    • Seal joints between intersecting planes w/ expanding foam The Green Roundtable (copyright © Green Roundtable 2007)
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    • Fireplaces are usually NOT an effective heating appliance! They lead to excessive heat loss via drafts up chimney. The Green Roundtable (copyright © Green Roundtable 2007)
    • Air sealing, online product sources • efi.org • conservationtechnology.com The Green Roundtable (copyright © Green Roundtable 2007)
    • Insulating • Resistance to heat flow (insulating ability) measured in R-value; not important to know how this is derived; mainly need to know that it’s a relative scale of effectiveness, and the higher the R value, the better the insulating value • Code represents absolute minimum; newer code has more stringent requirements; tied to window area; R-49 ceiling, R-21 walls, R-30 floors, R-13 basement typical The Green Roundtable (copyright © Green Roundtable 2007)
    • Insulating guidelines • Go for low-hanging fruit- e.g. add more attic insulation first if it is accessible and is not well insulated; Don’t forget the basement! • Remember that if you use A/C you are minimizing cooling expense by buttoning up your house as well as heating expense • Try to eliminate bridging (perimeter) heat loss through structural elements, as it greatly reduces overall insulation effectiveness • Look for additional opportunities to insulate (other than typical wall/ ceiling cavity insulation) The Green Roundtable (copyright © Green Roundtable 2007)
    • Basement/ foundation insulation often overlooked The Green Roundtable (copyright © Green Roundtable 2007)
    • Bridging heat loss • Conductive heat loss through structural members • Eliminate with: -Double wall construction (very expensive!) -Foam skin -Cross-banding attic batt insulation The Green Roundtable (copyright © Green Roundtable 2007)
    • Bridging heat loss- snow melts over roof rafters The Green Roundtable (copyright © Green Roundtable 2007)
    • Bridging heat loss caused wall-staining over structural members The Green Roundtable (copyright © Green Roundtable 2007)
    • Bridging heat loss through sill plates The Green Roundtable (copyright © Green Roundtable 2007)
    • Layer of foam minimizes bridging loss through sill; top of concrete foundation wall will also receive layer of foam The Green Roundtable (copyright © Green Roundtable 2007)
    • Thermograph to check heat loss through walls (insulation effectiveness) The Green Roundtable (copyright © Green Roundtable 2007)
    • Windows • Typical heat loss through windows about 20% • Performance measured in “U-value”; inverse of R- value; measure of material’s ability to conduct heat; the lower the U-value, the better • Look for U-value of .35 or less • Double-glazed, argon filled preferred; Diminishing returns with triple glazing • ‘Low-e’ coating reflects heat back into structure • Always look for Energy Star & NFRC labels (energystar.gov; nfrc.org) The Green Roundtable (copyright © Green Roundtable 2007)
    • NFRC Label The Green Roundtable (copyright © Green Roundtable 2007)
    • Windows • Used ‘tuned” glazing strategies • E.g., Use windows w/ low SHGC on west-facing windows; high SHGC on south-facing • Incorporate/ install overhangs & other shading devices where appropriate • Provide nighttime insulation The Green Roundtable (copyright © Green Roundtable 2007)
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    • Cellular insulating window shades can provide nighttime insulation The Green Roundtable (copyright © Green Roundtable 2007)
    • Side tracks make them easier to operate and reduce air leakage around edges The Green Roundtable (copyright © Green Roundtable 2007)
    • Green Practice: HVAC/ Plumbing The Green Roundtable (copyright © Green Roundtable 2007)
    • HVAC & Plumbing Systems • “Right-size” systems using analysis tools (Manual J) rather than rule-of-thumb methods; a right-sized system can be up to 40% smaller than a conventionally-sized system • Use demand pumps in DHW supply system (gothotwater.com) • Use heat recovery devices on DWV pipes (gfxtechnology.com) • Use instantaneous hot water heaters (tankless) The Green Roundtable (copyright © Green Roundtable 2007)
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    • Tankless water heaters • Examples of brands: Rinnai, Noritz, Takagi • Gas-fired typically more responsive and can provide needed capacity more effectively • Cost more than standard water heaters but last longer • More choices as to location/ placement • Direct-venting; e.g. can exhaust through wall • Look for min. flow rates of 0.3 – 0.5 gal./min. • Save energy by eliminating standing heat loss (vs. conventional tank-style water heater); estimated savings 24 – 34% The Green Roundtable (copyright © Green Roundtable 2007)
    • High-efficiency heating • Make sure heating systems have Annual Fuel Utilization Efficiency (AFUE) of at least 83% for oil- fired and 90% for gas-fired, and Seasonal Energy Efficiency Rating (SEER) of at least 13 for cooling systems • Boilers tend to have higher AFUE than furnaces • Closed-cycle, condensing-type boilers and furnaces are more efficient; they extract additional heat from warm flue gases • These systems often don’t need conventional flue pipe, they can side vent, but they require a dedicated combustion air source (coaxial flue pipe) The Green Roundtable (copyright © Green Roundtable 2007)
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    • Ductwork • Seal ducts; use duct mastic for this if possible, otherwise make sure duct tape is UL listed • Insulate ducts in unconditioned spaces; for cooling (A/C) ductwork, make sure insulation has external vapor barrier to minimize condensation • When insulating ducts in unconditioned basement, you may make basement too cold; insulate basement walls instead The Green Roundtable (copyright © Green Roundtable 2007)
    • Lighting • Use dimmer switches & occupancy sensors • Use solar landscape lights • Use motion sensor outdoor lights • Put timer switches on bathroom fans • Spec CFL’s & fluorescents The Green Roundtable (copyright © Green Roundtable 2007)
    • Appliances • Buy Energy Star! • Specify horizontal axis washing machines • Specify dishwashers w/ booster heater • Don’t specify oversized AC equipment! The Green Roundtable (copyright © Green Roundtable 2007)
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    • Energy Star savings calculators http://www.energystar.gov/index.cfm?c=dishwash.pr_dishwashers http://www.energystar.gov/index.cfm?c=clotheswash.pr_clothes_ washers http://www.energystar.gov/index.cfm?c=boilers.pr_boilers The Green Roundtable (copyright © Green Roundtable 2007)
    • General analysis tools A general list of tools offered by the U.S. Department of Energy are available over the web at: http://www.eere.energy.gov/buildings/tools_directory/su bjects.cfm/pagename=subjects/pagename_menu=whole_ building_analysis/pagename_submenu=load_calculation The Green Roundtable (copyright © Green Roundtable 2007)
    • Sweetening the pot The Green Roundtable (copyright © Green Roundtable 2007)
    • Rebates and incentives • Federal Energy Policy Act of 2005 • Energy efficient mortgages • MA state sales tax exemption • MA state renewable energy tax credit • Mass Technology Collaborative’s Commonwealth Solar Initiative • Utility incentives • See DSIRE database (Database of State Incentives for Renewables & Efficiency): http://www.dsireusa.org/ The Green Roundtable (copyright © Green Roundtable 2007)
    • Federal Energy Policy Act of 2005 Examples: • Energy Star windows/ skylights: 10% of cost up to $200 for all windows • Exterior/ Storm doors: 10% of cost up to $500 • Insulation: 10% up to $500 • Geothermal heat pump: $300 • http://www.energy.gov/taxbreaks.htm The Green Roundtable (copyright © Green Roundtable 2007)
    • Energy Efficient Mortgages • Allows you to increase your debt-to-income ratio • Remodelers/ Refinancers: -Owner gets all the EEM benefits without moving. -Make improvements which will actually save money. -Increase the potential resale value . • Home Energy Rating System (HERS) report must indicate that home will save money as a result of the improvements- http://www.energy.ca.gov/HERS/; http://www.energyratings.org/ • For more info: http://www.pueblo.gsa.gov/cic_text/housing/energy_mort /energy-mortgage.htm The Green Roundtable (copyright © Green Roundtable 2007)
    • MA Renewables Tax Credit • Personal tax credit • Solar Water Heat, Solar Space Heat, Photovoltaics, Wind • 15% of cost up to $1000 • Excess credit may be carried forward three years • http://www.state.ma.us/ doer/programs/renew/renew.htm#taxcred The Green Roundtable (copyright © Green Roundtable 2007)
    • MA State Sales Tax Exemption • Solar Water Heat, Solar Space Heat, Photovoltaics, Wind, Geothermal Heat Pumps • 100% of sales tax exempt; no maximum • http://www.state.ma.us/ doer/programs/renew/renew.htm#taxcred The Green Roundtable (copyright © Green Roundtable 2007)
    • MTC Small Renewables Initiative • PV, wind, microhydro • Rebates up to $50,000 • See http://www.masstech.org The Green Roundtable (copyright © Green Roundtable 2007)
    • MTC Commonwealth Solar • $68 M Funding •http://www.masstech.org/renewableenergy/commonw ealth_solar/index.html The Green Roundtable (copyright © Green Roundtable 2007)
    • Typical utility rebates •High-efficiency space heating equipment •High-efficiency indirect water heating equipment •ENERGY STAR® qualified windows •ENERGY STAR® qualified thermostats •ENERGY STAR® qualified central air conditioning •ENERGY STAR® air source heat pump systems The Green Roundtable (copyright © Green Roundtable 2007)
    • Resources GRT: www.greenroundtable.org Building Green: www.buildinggreen.com Energy Star: www.energystar.gov Charles River Watershed: www.crwa.org US Green Building Council: www.usgbc.org Renewable Energy: www.nrel.gov US DOE: www.eere.energy.gov/buildings/ EPA: www.epa.gov/ne/greenbuildings Residential Green Building Guide: A Web Source Book for New England www.epa.gov/ne/greenbuildings NAHB: Model Green Home Building Guidelines: www.nahb.org The Green Roundtable (copyright © Green Roundtable 2007)
    • And don’t forget about NEXUS! • Upcoming workshops • Reference library • Samples library • Cyber Lounge • Online resources at nexusboston.com (in the pipeline) • Local green building community The Green Roundtable (copyright © Green Roundtable 2007)
    • Local Resources The Green Roundtable (copyright © Green Roundtable 2007)
    • THANK YOU www.greenroundtable.org info@greenroundtable.org 617-374-3740 The Green Roundtable, Inc. (GRT) is an independent non-profit organization whose mission is to mainstream green building and sustainable design and become obsolete. We work toward this goal by promoting and supporting healthy and environmentally integrated building projects through strategic outreach, education, policy advocacy and technical assistance. Located in downtown Boston, NEXUS welcomes all to come ask questions, research topics, and attend tours and www.nexusboston.com events on green building and sustainable 38 Chauncy Street, Boston design innovation. The Green Roundtable (copyright © Green Roundtable 2007)