Making The Case For Green

The Green Roundtable
and

Making the Case for Green-
Basic economics

(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.


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?


Why do green….

4

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

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

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

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


Water tables are now falling in countries that
contain over half the world’s people

9


There are currently 1,243 EPA Superfund
sites on the National Priorities List and 60
more proposed (as of 3/20/07)



The incidence of asthma has increased
dramatically over the last 25 years in the U.S.
and other industrialized nations.

11


The EPA estimates that indoor air can be up
to five times as contaminated with VOCs as
outside air.

12


The EPA also reports that the airborne
contaminants found in our homes are three
times more likely to cause cancer than the
pollutants outside



Cancer clusters have been identified in
some more-affluent communities and have
been attributed to chemically-intensive
landscape management practices

14


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



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 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

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

19

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


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%


Food for thought….

22

23

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

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

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

A solution:
Green Building

27

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 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

Some other motivators:

• The cool factor

• The “shiny metal objects” mentality

• Peer pressure

30

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

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


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 LEED Credit Categories

Sustainable Sites

Water Efficiency

Energy & Atmosphere

Materials & Resources

Indoor Environmental Quality

Innovation & Design Process


Cornerstones of green building (structure itself)

Site Site

Site Site

36

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


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


Recycled Content

Post-Consumer vs. Pre-Consumer
aka Post-Industrial


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


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


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

Economics of green building


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!


Additional construction costs


Additional Pitfalls

• Uninformed & resistant code and municipal officials

• Products that ‘go away’

• Sourcing materials

• “Greening” small-scale projects


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


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
(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.

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!


Underlying all:

Scale
Scale
Scale


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.


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)


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 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


Low-hanging Fruit
(A sampling)


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


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

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


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'


Low-water shrubs:

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'


Low-water groundcovers:

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"


Low-water perennials:

New England Aster Aster Novae-angliae 15-30"
CommonBlanketflower Gaillardia aristata 24-36"
Moonbeam Coreopsis verticillata 24-36"
Purple Coneflower Echinacea purpurea 24-36"


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


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


Advanced framing & efficiency

• Provides more room for insulation!

• Reduces bridging heat loss


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


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


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


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


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


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


A sampling of strategies &
approaches for reducing life-
cycle cost or TCO

79

Green Practice:
Water conservation


MWRA
A water conservation resource

Order a free water saving kit at:
www.mwra.com/04water/html/watsense.htm


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


83

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


Green Systems:
Gray water


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


Gray water: A direct approach

http://www.gaiam.com/product/eco-home-outdoor/energy-efficient-
climate-control/energy-saving-tools/toilet+lid+sink.do

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!


http://www.cleanairgardening.com/33galrainbar.html


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


Drip emitters


Soaker Hose


Energy Conserving
Design Strategies (a sampling)


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


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


Thermal mass: additional benefits
• Acoustic comfort

• Increased structural integrity in some situations


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


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


Design Strategies: Passive solar


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…


5 Major elements of
Passive Solar
• Aperture/ Collector (glazing)

• Absorber

• Thermal storage (mass)

• Distribution

• Control


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.


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


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

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

Angled glass may not be the best configuration,
especially without an overhang!

Skylights may contribute to summer overheating
and winter heat loss.

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


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”)


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


Sky tube (TDD)


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)

Light shelves shade window
while providing natural daylight
via light reflected from top
surface

Can help light to penetrate
deeper into structure


Suggested Room Surface
Reflectances:
Ceilings: > 80%
Walls: 50%-70%
Floors: 20%-40%
Furnishings: 25%-45%


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/


Green Practice:
Improving the Building Envelope


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.


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.


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.


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!


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


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

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


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)


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


Housewrap to
minimize air
infiltration &
protect from
moisture


Blower door
test to
measure air
leakage


Air leakage pathways

Air leakage proportion through various pathways


Attic hatches/ scuttles are a major leakage pathway


A commercial solution for attic openings

See also www.efi.org


Insulate header/ rim joists w/ rigid foam & expanding foam


Seal joints between intersecting planes w/ expanding foam


Fireplaces are usually NOT an effective heating appliance!
They lead to excessive heat loss via drafts up chimney.


Air sealing, online product
sources

• efi.org

• conservationtechnology.com


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


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)

Basement/ foundation insulation often overlooked

Bridging heat loss

• Conductive heat loss through structural members

• Eliminate with:
-Double wall construction (very expensive!)
-Foam skin
-Cross-banding attic batt insulation


Bridging heat loss- snow melts over roof rafters

Bridging heat loss caused wall-staining over structural members


Bridging
heat
loss through
sill plates


Layer of foam
minimizes bridging
loss through sill;
top of concrete
foundation wall
will also receive
layer of foam


Thermograph to check heat loss through walls (insulation effectiveness)


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)

NFRC Label


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


Cellular insulating window shades can provide nighttime insulation


Side tracks make them easier to operate
and reduce air leakage around edges


Green Practice:
HVAC/ Plumbing


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)


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%

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)


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


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


Appliances
• Buy Energy Star!

• Specify horizontal axis washing machines

• Specify dishwashers w/ booster heater

• Don’t specify oversized AC equipment!


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


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


Sweetening the pot


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/


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


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

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


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


MTC Small Renewables Initiative

• PV, wind, microhydro

• Rebates up to $50,000

• See http://www.masstech.org


MTC Commonwealth Solar

• $68 M Funding

•http://www.masstech.org/renewableenergy/commonw
ealth_solar/index.html


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


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


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


Local Resources


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.

Making The Case For Green

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