Customizing HEED for a Small Utility District

Murray M and Pablo LaRoche

ban Design

.edu

ilne, Carlos Gomez, UCLA Department of Architecture and Ur

A 90095 Los Angeles, Cemail: milne@ucla

Jim Barnett, Principal Architect of New Construction Services

Sacramento Municipal Utility District 6301 S Street

emMS A203, Sacramento CA 95817 ail: jbarnet@smud.org

ABSTRACT: In California, the four largest utilities serof the State’s residential customers, whilesmall utility districts serve the rest of the pThese smaller utilities individually do not have

ve 80 pe over 40opulat

theconomic leverage to provide their customers wit

ed by the same

-effective eneodeling ns when

e Sacram spend almost

billion dollars per year on new homes and on hese

nefits os to make

l imould be

is how to reach this particular group of ratepayers, and how to answer questions that apply to their specific homes. HEED (Home Energy Efficient Design) is a free homeowner- friendly design tool that shows the energy implications of new construction and remodeling decisions. A custom version of HEED was developed at UCLA to address SMUD’s rate structures, climate data, and home construction practices. It will be made available on SMUD’s web site.

ayers Improve Efficiency

arket in Sacramento odeling and additions ues over $128 million tial Alterations and 1). At least three

times this amount of work is done by do-it-yourselfers hout permits, bringing

on dollars annually.1 onstruction accounts for

is money comes 6 residential ratepayers tility District (SMUD).

easy way to visualize the

ng some of their funds in nc their own homes ve a n SMUD’s ptio problem is how to

cular group of SMUD ratepayers who ak nd how to answer

particular homes. Table 1: Residential Building Permits Issued in Sacramento County

rcent

ion. e h the the

1. Helping SMUD RatepTheir Home’s Energy There is a large custom home mand endless activity in the remsector. Sacramento County issin Building Permits for ResidenAdditions every year (see Table large array of ratepayer support tools offer

big four. But their customers struggle withproblems, such as how to make costefficient decisions when repairing or remhomes, or how to evaluate different optiocomparing potential new home purchases. The 472,666 residential ratepayers in thMunicipal Utility District (SMUD)

rgy their

ento o

and informal subcontractors witthe total to roughly half a billiNew Single Family Home Canother $1.4 billion annually. All thout of the pocket of the 472,66in the Sacramento Municipal U

tw

residential remodeling and repairs. If thomeowners can be shown the economic beinvesting even a tiny fraction of these fundtheir homes more energy efficient, the potentiaon SMUD’s energy consumption patterns wsignificant. The problem

f economic benefits of investi

pact

energy consum

Giving these homeowners an

energy efficie y improvements towill in turn ha significant impact o

n patterns. The reach the partiare about to m e these decisions, aquestions that apply to their own

New Single Family $ 1,399,728,000 New Multi-Family $ 133,506,000

Alterations and Additions $ 128,889,000 Total Residential Building Permits $ 1,662,124,000

(Construction Industry Research Board, May 2002).

SMUD currently offers incentives to new hbuilders to construct SMUD Advantagexceed California’s Title 24 energy standaThe incentives go to the builders in the formHookup Fee discounts when they make aapplication for electric service. The SMUD

ome e Homes th

rds by of

subdivi Adva

Home Program has been available to builders sinomes exi

gy Coivision

tants pely softll builly accurate

to help them quantify the energy impact of all their design and construction decisions. SMUD wanted to give these people a free “what if” tool that can quickly calculate the energy savings of alternative strategies in their new home construction and remodeling projects.

ratepayers get their nd seek answers to

nergy savings in their ften contact SMUD staff SMUD Energy and ffers some classes on cate customers about

ruction. However ttendees always require their particular project.

ergy specialists in hey are generally

MUD Advantage homes also on staff who is

about residential design and offers his experience as time permits, however his main expertise and effort is assigned to commercial daylighting simulations. HEED is thought to be the needed extra resource to augment SMUD staff.

at 35%.

sion ntage

ce st in

de s, rform ware ders

An increasing number of SMUDhands dirty on “home makeovers,” atheir questions relating to econstruction projects. They oand seek the resources of the Technology Center. SMUD oweekends and evenings to eduefficient home design and consthelpful the classes may be, amore specific assistance withSMUD employs three residential enthe new construction group, but tinundated with the 6,000 Sbuilt per year. One architect isknowledgeable

1992, and now over 40,000 Advantage hSacramento County. To predict energy savings for Title 24 Enercompliance on these production home subdmechanical contractors and energy consulenergy simulations using complex and costprograms. Individual homeowners and smaneed a simple, easy-to-use tool that is equal

Fig. 1 Floor Planner: HEED allows users to draw in their floor plan by selecting the “building” icon, then click and drag to fill in squares on a four-foot module. This example shows the lower floor of a three story home with a

driveway and garage on the north.

On a daily basis, the typical questions that relate to things like the benefits and paybacparticular efficiency strategy. These includand their placement, glass tints and coatinroof insulation values, radiant barrier beneconditioner efficiencies and system opstaff will offer information about all of thbut does not have the resources to run enesimulations to give each customer individetailed payback information. The fistrategy greatly affects the decision to impleefficiency measure. It is important to quanlong-term financial benefits for a strateimplemented. It is also equally important toindoor environmental comfort. SMUD neetool that could be used by anyone, that cthe energy questions quickly. S

are askk for ae wind

gs, wallfits, an

tions. SMUese featrgy

dualized rst cost of an

menttify th

gy to be simu

ded anould answ

MUD found that HEED not only answered energy savings questioalso calculated indoor air temperatures. HEED se ved

be very beneficial for the architectural design community

ion of HEE

, architcustom

features s.

free user ated initially to

ntial ratepayers in the Southern California ergy efficient

remodeling home. In

, HEED makes it

bilities including other

ED lets ratepayers quickly draw in their own home’s floorplan (by filling squares in a checkerboard), then define their windows and drag them to the correct location on each elevation.2 3 A 3-D image of their home can be clicked and rotated to its exact compass heading. Ratepayers can easily describe their home’s construction by choosing from lists of building components like floors, roof, insulation, etc. Then they can very quickly run through half a dozen “what if” possibilities in a few minutes, and at each step see bar charts showing differences in their annual energy bills compared to a

ocal utility’s actual rate EED is designed to be

to understand and tually driven by a very

e algorithm. HEED AE’s Bestest

rocedure against the results of programs like DOE-2 and Blast.4 Recently HEED’s ability to predict indoor

ated using a set of full

four facts about their age, number of stories, and

matically designs a ergy Code (Title 24)

esigns Scheme 2 that is r these two act as

help users evaluate their own designs and revisions. Note that individual components, like

t meet Title 24 prescriptive ew home’s overall energy

ption is less than the performance of Scheme sion.

to HEED for

Climate Data

ed ows and d air D

ures

Edison (SCE) service territory make endesign decisions when choosing repair and options, or when buying or designing a newanticipation of serving other constituencieswas programmed in a modular fashion that relatively efficient to add in new capadifferent rate structures and climate data forutility districts. Previous ASES papers illustrated how HE

Title 24 home, using their lstructures (Fig.7 and 8). Hextremely easy for ratepayerssimple to use, but it is acsophisticated hourly heat balanchas been validated using ASHRp

y an e

late easy er

ns but

air temperatures has been validheight test cells.5 HEED starts by asking the user home (zipcode, square footbuilding type), and then it autohome that meets the California Enfor their climate zone. It next dmore energy efficient. Togethebenchmarks to

rthe need of the basic user but would also

doing sophisticated passive solar design. 2. Creating the SMUD vers D

ects

1, the Code Compliant ver 3. New Features AddedSMUD Ratepayers:

walls or windows need nostandards, as long as the nconsum

SMUD asked UCLA to build a version of HEED specifically for small builders, contractorsand their more knowledgeable residential They asked for a number of additional new addressing their district’s particular need HEED (Home Energy Efficient Design) is a friendly energy design tool that was crehelp reside

ers. : All of SMUD’s zipcodes and the weather data for Sacramento’s Climate Zone 12 were added to HEED’s database. Incidentally, an additional feature was added that allows climate data for over 500 stations around the world to be loaded directly from the EnergyPlus web site, via the hotlink in the HEED web page6.

Fig. 2: SMUD’s Electric Rates Screen

Electric Rates: New Electrical Rates screenadded to display SMUD’s Residential RatThis means that once

s werees (Fig.

SMUD ratepayers have typtheir zipcode, all their utility rates and climate da

2). ed in ta is

Level of Insulation: Because thhelp homeowners who are mrepair decisions for existing homthat lets them choose differentdepending on the year when t5). Other options allow for o

loaded automatically. Fuel Rates: In Sacramento, natural gas is pmost of SMUD’s customers by Pacific GaElectric. Therefore a new PG&E gas raalso created. Also the options of propane oil were added, which are

rovide to s and

tes screenand heat

common alternatives inmore rural sections of the SMUD service territory(Fig.3). All these electrical rates and gas rates canchanged by the user on the screen.

d

was ing the be

insulation, which are two commproject. Radiant Barriers in Roofs: ReflBarriers are required in Sacramento’s climthe Prescriptive approach is compliance. However, the larghomes use the Performance appTitle 24 and many do not incoA n

is tool is intended to aking remodeling and

es, there is a screen levels of insulation

heir home was built (Fig. lder uninsulated homes

that were partially updated by adding attic or floor on do-it-yourself

Oil

given the option here to incluThe user must then use other exceed the performance of the Ticompliant building. Wall Construction Options: Mahave been added to the basic Waconstruction practices common in SMUD’s czone (Fig.6). If the user selectnot accommodate the level of iselected, then the expert systemit to the next better assembly.selected the insulation level to mcode in Sacra

ective Foil Radiant ate zone if

used for energy e majority of new roach to comply with

rporate radiant barriers. ew set of options for roof construction now

automatically includes radiant barriers, but the user is de or omit them (Fig.5). strategies to meet or

tle 24 Code

Fig: 3: Fuel Rates for Gas, Propane, an

Complex

d Heating

Floor Plans: HEED has been modified tnt sers cse by

r Down b

bors an attached r

w Glazing and Frame Options:

o

an

utton d

to 2x4s with exterior polystyrbecause a 4-inch deep stud spacR13 insulation, but the prescriptivin Sacramento’s Climate Zone 12. happens if the user had clicked concrete block wall, which wwith

accommodate floor plans that have a differefootprint on each floor level (Fig.1). Now ueasily create the floorplan of their own housimply clicking on squares and filling in acheckerboard, then clicking on the Up oto fill in the other floors. As before, neighgarages can be added at any floor, eitherfree standing. Windo

o

Additional of glass and the options for either aluminum framnon-metallic frames (wood or vinyl) have been adper ASHRAE7 options (Fig.4). These are basic radio-button lists that allow users to simply click on any window assembly they wish. However, if they have the actual NFRC (National Fenestration Rating Council) sticker data from a manufactured window they are considering using, it can be added on the Advanced Window screen for up to 25 different windows.

types es or ded

Context Based Help: If uanything on any screen, they onl“Help” icon. This context-specibeen expanded to explain al

ny new wall details ll screen based on

limate ed a wall system that will nsulation initially automatically changes

For example, if the user eet the current energy

mento’s climate zone, and then selected 2x4 stud construction, the expert system will change it

ene insulation. This is e will only hold up to

e code requires R19 The same thing

on a filled-core ould be changed to block

exterior polystyrene foam.

sers have questions about y need to click on the

fic information has l these new features added

for SMUD ratepayers. In addition, the “Advice” icon in HEED has been expanded by adding the web sites, rebate programs, and other background information supplied by SMUD. Spanish Language Version: HEED is one of the few Energy Efficiency software programs that are available in either English or Spanish. Therefore all this new material has been translated into Spanish and added to the final full function Spanish version of HEED.

FI

Fig.4: Glazing

ig.5: nsulation

Fig.6: alls W

of payer

ACKNOWLEDGEMENTS: These new additions to HEED weEnergy Design Tools Group under Sacramento Municipal Utility District

Fig. 7: Energy Costs Bar Chart shows the cost

Electricity (blue) and Gas (red) for a SMUD rate

s of of

Housing”, with Carlos Gomez,Kobayashi, Tim Kohut, and Paki MASES 2002, American Solar E 3 “Heeding the Needs of

Fig. 8: Summary Table shows the Eneach of the above schemes and the

savings compared to Scheme 1

ergy Cost percentage

Meets Energy C

Summary Table:

, ode.

user

Makers,” Murray Milne, Carlos GPablo LaRoche, Proceedings of ASES 2003Energy Soc The Summary Table shows the

ch money each of their different designs will save compared to Scheme 1, the Titl

helpfudvantage

ve the e Title 24.

4. Deployment: User Support

exactly how mue 24 l for

4 HEED produces valid heating different test buildings using ASHof Test for the Evaluation of BuildinComputer Prog

Basecase Home (Fig.8). This is especiallythose builders interested in the SMUD AHomes Incentives, because it shows which combinations of design features can achiedesired 35% improvement abov

Web Site Delivery: This newHEED will be hosted on UCTools web site (both English anwhere it can

SMUD version of LA’s Energy-Design-

d Spanish versions) be downloaded at no cost by SMUD

ratepayers, and to which it can be transparently linked from SMUD’s own web sites.

Workshops and Media: In addiworkshops are a

tion, a series of lso planned in SMUD’s Energy &

Technology Center who serve various SMUD user cies. Bill stuffers and stories in local media

can help jumpstart user acceptance. constituen

re developed by the UCLA contract to the

, and are now available to all users. The original version of HEED was supported by

er a contract ia Edison, Gregg Ander

TG Energetics, Malcolm e wish to thank all our many beta-testers

ments and suggestions.

the California Public Utilities Commission, undadministered by Southern CalifornManager, in association with CLewis President. Waround the country for their com 1 The growth in the Home Improfueled by the Baby Bo

vement Industry has been

omers, who have been a major factor ts: Home Improvement

i.orgin the rise of home center outleResearch Institute (HIRI), www.hir

2 “Using HEED to Design Energy Efficient Affordable Yoshi

uthig, Proceedings of nergy Society

Home Improvement Decision- omez, and

, American Solar iety

and cooling results for 28 RAE’s “Standard Method

g Energy Analysis rams”, ANSI/ASHRAE Standard 140-2001,

(see “BestTest Validation” on HEED web site) 5 “Automatic Sun Shades, An Experimental Study”, Pablo LaRoche and Murray Milne, Proceedings of ASES 2004, American Solar Energy Society 6 A file in the download folder called READ-USA.TXT explains how to use weather data directly from the EnergyPlus web site for over 500 locations throughout the world. HEED, Home Energy Efficient Design, is available at no cost on www.aud.ucla.edu/heed 7 ASHRAE Handbook of Fundamentals, Tables 4 and 13, Chapter 30, 2001

: Simply providing a new tool does not guarantee that it will have a significant impact. Users have all kinds of questions; some extremely simple and others complex enough to require a revision in the program. That is why UCLA will staff an email User Support Hot-Line for SMUD ratepayers.