TABLE OF CONTENTS 1

Affordable Zero Energy 

K–12 Schools:

The Cost Barrier Illusion

Paul Torcellini, National Renewable Energy Laboratory

Sarah Zaleski, U.S. Department of Energy

Maureen McIntyre, McIntyre Communications Inc.
2

Cover photo: Jennings Creek 

Elementary, a zero energy 

school in Bowling Green, 

Kentucky, cost $1.5 million 

less to build than the average 

Kentucky school and saves 

more than $195,000 a year in 

energy costs compared to a 

conventional school.

Photo from Sherman Carter Barnhart 

Architects, Chris Phebus Photography

NOTICE

This manuscript has been authored by employees of the Alliance for Sustainable Energy, LLC 

(“Alliance”) under Contract No. DE-AC36-08GO28308 with the U.S. Department of Energy (“DOE”). 

Funding provided by the U.S. Department of Energy Building Technologies Office.

This report was prepared as an account of work sponsored by an agency of the United States 

government. Neither the United States government nor any agency thereof, nor any of their 

employees, makes any warranty, express or implied, or assumes any legal liability or responsibility 

for the accuracy, completeness, or usefulness of any information, apparatus, product, or process 

disclosed, or represents that its use would not infringe privately owned rights. Reference herein to 

any specific commercial product, process, or service by trade name, trademark, manufacturer, or 

otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring 

by the United States government or any agency thereof. The views and opinions of authors 

expressed herein do not necessarily state or reflect those of the United States government or any 

agency thereof.

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at 

www.nrel.gov/publications.

U.S. Department of Energy (DOE) reports produced after 1991 and a growing number of pre-1991 documents are 

available free via www.OSTI.gov.

NREL prints on paper that contains recycled content.

NREL is a national laboratory of the U.S. Department of Energy 

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

Contract No. DE-AC36-08GO28308

Technical Report

NREL/TP-5500-80766

December 2021

National Renewable Energy Laboratory 

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov
3

The budget for Discovery Elementary School, a zero energy 

school in Arlington, Virginia, was fixed from the outset, and 

the innovative architectural and engineering team completed 

the project—including the solar photovoltaic system—for less 

money than the district had allocated.

Photo from VMDO Architects, Alan Karchmer Photography
4 ACKNOWLEDGMENTS

ACKNOWLEDGMENTS

The authors acknowledge the zero energy building professionals and school district officials who generously shared their 

time and expertise. Their input was invaluable, and, thanks to these building industry and education leaders, zero energy K–12 

schools are becoming better understood, more widely adopted, and more affordable. They included:

Nathaniel Allen, U.S. Department of Energy

John Balfe, Manager, Buildings and Communities Solutions, 

Northeast Energy Efficiency Partnerships

Nancy Bartolo, Facilities Consultant, Hermosa Beach City 

School District

Roderick Bates, KieranTimberlake

Ray Beaufait, PE, CMTA, Inc.

Gary Brock, AIA, Associate, HMFH Architects, Inc.

John C. Chadwick, AIA, Assistant Superintendent, Facilities 

and Operations, Arlington [VA] Public Schools

Christos Chrysiliou, AIA, Director Architectural and 

Engineering Services, Los Angeles Unified School District

Stephanie Carlisle, KieranTimberlake

Gardner Clute, AIA, MOA ARCHITECTURE, formerly with 

Cuningham Group Architecture, Inc.

Danielle M. Davis, MBA, Marketing Manager, 

SfL+a Architects

John Diffenderfer, AIA, President/Principal, 

Aedis Architecture

Suni Dillard, AIA, Associate, HMFH Architects, Inc.

Peter Ewers, Ewers Architecture

Jess Farber, PE, Vice President, CMTA, Inc.

Robbie Ferris, AIA, Manager, Firstfloor Energy Positive; CEO, 

SfL+a Architects

Alexandra Gadawski, Designer, HMFH Architects, Inc.

Tony Hans, PE, National Director of Sustainable Projects, 

CMTA, Inc.

Nathan Herrero, AIA, Principal, SVA Architects

Paul Hutton, FAIA, Principal, Chief Sustainability Officer, 

Cuningham Group Architecture, Inc.

Heather Jauregui, Sustainability Specialist, Perkins Eastman

Nik Kaestner, Director of Sustainability, San Francisco 

Unified School District 

Stephen Kieran, KieranTimberlake

Nate Kinsey, [former] Energy Manager, 

San Francisco Unified School District 

Wyck Knox, AIA, Principal, VMDO Architects

Mark Koll, [former] Coordinator of Design, Engineering, and 

Sustainability, Horry County (SC) Schools

Melissa Kops, AIA, Pirie Associates Architects

William Leddy, FAIA, LEDDY MAYTUM STACY Architects

Cathy Lin, Energy Manager and Stormwater Program 

Administrator, Arlington [VA] Public Schools

Stephanie MacNeil, AIA, Associate, HMFH Architects

Dan Malmgren, Director of Facilities, 

Bishop O’Dowd High School

Jerry Marshall, Energy Manager, Firstfloor Energy Positive

Chris McIntyre, CPA, Chief Financial Officer, 

Warren County [KY] Public Schools

Jeff Medwetz, Architect, Project Manager of Energy Systems, 

Boulder Valley [CO] School District

Sean O’Donnell, AIA, Perkins Eastman

Sean Pringle, PE, Project Engineer, Tighe & Bond

Mary Rankin, AIA, Perkins Eastman

Jonathan Santoso, Mechanical Engineering Intern, 

Integral Group

Scott Shell, Principal, FAIA, EHDD Architecture

Jana Silsby, AIA, Partner at Creative X2 Studio

Kenny Stanfield, AIA, Principal, Sherman Carter 

Barnhart Architects

Jenn Tamburino, CMTA, Inc.

Kim Trenbath, National Renewable Energy Laboratory

Brian Turner, PE, CMTA, Inc.

Mike Wilson, Facilities Director, 

Warren County [KY] Public Schools

The authors would also like to thank Amy Upton at Grimm 

+ Parker Architects, Cathie Welsch and Newbie Walters at 

Sherman Carter Barnhart Architects, Joe Burch at Horry 

County Schools, and Wyck Knox at VMDO Architects, for 

allowing us to use images of their projects. Finally, thank you 

to NREL colleagues Marjorie Schott for her graphic design 

and Michael Deru for his technical review.
TABLE OF CONTENTS 5

TABLE OF CONTENTS

ACKNOWLEDGMENTS. 

INTRODUCTION. 

Background.

Schools Take the Lead.

RESEARCH RESULTS. 

The Research. .

The Results. .

Key Takeaways. .

COST CONTROL. 

Establishing a Budget and Energy Goal. .

Shifting Costs. .

Choosing a Procurement Process. .

Measuring and Verifying Performance. .

BENEFITS AND CHALLENGES. 

Benefits. .

School Districts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Students and Staff. .

Communities. .

Challenges. .

Risk Management. .

School Governance and Funding. . . . . . . . . . . . . . . . . . . . . . . . . 22

CASE STUDIES. 

Small Decisions, Big Benefits: 

Warren County Public Schools. . . . . . . . . . . . . . . . . . . 24

RICHARDSVILLE ELEMENTARY SCHOOL 

PROJECT DETAILS. .

JENNINGS CREEK ELEMENTARY SCHOOL 

PROJECT DETAILS. .

Robust, Affordable K–12 Education: 

Arlington Public Schools. .

DISCOVERY ELEMENTARY SCHOOL PROJECT DETAILS. .

A Path to Energy Positive: Horry County Schools. .

ST. JAMES INTERMEDIATE SCHOOL PROJECT DETAILS. .

CONCLUSIONS . 

ACRONYMS. 

GLOSSARY. 

APPENDIX A: ZERO ENERGY SCHOOLS 

ACCELERATOR. 
6 I

Jennings Creek Elementary School in Bowling Green, 

Kentucky, was designed to operate at an energy use 

intensity of 17.5 kBtu/ft2·yr, but it has exceeded 

expectations and is operating at 15.5 kBtu/ft2·yr.

Photo from Sherman Carter Barnhart Architects, Chris Phebus Photography

INTRODUCTION
Int

Despite the many examples of zero energy (ZE) schools built at costs comparable to or 

less than conventional schools, the perception persists that ZE schools cost more. Evaluating 

this belief is important because the perception of risk alone can drive up costs (see Risk 

Management, page 22). 

1 https://www.documents.dgs.ca.gov/sam/SamPrint/new/sam_master/sam_master_file/chap1800/1815.31.pdf

2 https://www.energy.ca.gov/programs-and-topics/programs/energy-efficiency-existing-buildings

3 https://www.energy.gov/sites/prod/files/2015/09/f26/bto_common_definition_zero_energy_buildings_093015.pdf , https://youtu.be/FysJKq5yCfg

4 https://www.nrel.gov/docs/fy17osti/67233.pdf

5 https://newbuildings.org/resource/2020-getting-to-zero-project-list

6 https://www.ashrae.org/aedg 

7 https://zeroenergy.org/about/

8 https://zeroenergy.org/project-types/schools/zero-energy-schools-accelerator/

The pressures to contain costs in school design and 

construction can be intense, and—because many stakeholders still cite cost as a major barrier to designing and 

building a ZE K–12 school—those pressures can thwart 

efforts to pursue a ZE or zero energy ready (ZER) project. 

By examining the costs of a subset of existing ZE schools 

and the strategies used to contain those costs, architects, 

engineers, owners, and researchers are challenging the 

notion that cost is a barrier to building ZE schools. 

As one architect who has designed multiple ZE schools 

put it, “The people who say zero energy is unaffordable 

or unfeasible are usually those who have never done it.”

Background

Interest in very low energy buildings is growing across 

the United States. California, for example, has adopted ZE 

targets for 50% of the floor area of existing state-owned 

buildings by 2025 and for all new or renovated state 

buildings beginning design after 2025.1 California has 

also set a target of making all new commercial buildings 

ZE by 2030.2 Several other states are considering similar 

measures and have established task forces to work on 

the issue.

A ZE building produces as much energy—usually with 

solar photovoltaics (PV)—as it consumes on an annual 

basis.3 ZER buildings are designed and built to accept an 

on-site renewable energy system, but the installation is 

postponed for budgetary or other reasons. The number 

of ZE and ZER buildings in the United States is increasing 

as the process of getting to ZE is refined and simplified 

by forward-thinking building owners, communities, and 

design and building professionals. 

Advances in technology and integrated design together 

with sharp reductions in the cost of renewable energy 

make ZE feasible4 and affordable now. These trends are 

corroborated by a dramatic increase in the number of 

documented ZE buildings.5

As one architect who has designed multiple ZE 

schools put it, “The people who say zero energy is 

unaffordable or unfeasible are usually those who 

have never done it.”

Schools Take the Lead

K–12 schools are leading the market shift from buildings 

that consume energy to buildings that produce as much 

renewable energy as they use. School buildings often 

reflect the larger community’s ideals of fiscal responsibility, educational innovation, and environmental stewardship, and successful ZE schools provide a collection of 

compelling case studies with measured energy performance data. 

For example, a team of school design experts and owners supported by energy modeling simulations from the 

National Renewable Energy Laboratory assembled the 

Advanced Energy Design Guide for K–12 School Buildings: 

Achieving Zero Energy (ZE K12 AEDG), which was published in 2018.6

 This free, downloadable guide provides 

a set of energy use intensities (EUIs, a measure of energy 

consumption expressed in thousands of British thermal units per square foot per year [kBtu/ft2

·yr]) for K–12 

buildings, practical guidance for achieving those EUIs, 

and a sample of schools that have achieved the targets. 

Schools that meet these EUI criteria but postpone installing a renewable energy system are considered ZER.7

In addition, as part of the U.S. Department of Energy’s 

Zero Energy Schools Accelerator,8 the National Renewable Energy Laboratory published A Guide to Zero Energy 
8 I

and Zero Energy Ready K–12 Schools9 with editorial 

content support from school districts, nongovernmental 

organizations, and ZE design and construction professionals. The free, downloadable document is organized 

into eight steps:

1. Conducting a building needs assessment

2. Engaging stakeholders

3. Including ZE goals in the procurement 

process

4. Selecting a design and construction team 

committed to ZE goals

5. Integrating ZE goals into design

6. Achieving ZE goals during construction and 

commissioning

7. Evaluating performance and engaging 

occupants

8. Showcasing and replicating a ZE school.

9 https://www.nrel.gov/docs/fy19osti/72847.pdf

Each step contains a short anecdote from a school district offering a quick synopsis of that district’s experience 

with the step as well as a list of relevant resources. More 

technical sources can be found in a reference list at the 

end of the publication.

There are now enough ZE schools operating that there 

is less risk associated with tackling a ZE project. Design 

firms that commit to ZE can, however, expect to invest in 

educating staff and clients, improving modeling capabilities, and identifying and adopting cost control strategies. 

There are now enough ZE schools operating that 

there is less risk associated with tackling a ZE 

project. 

The process is analogous to the switch to computer-aided design (CAD) by architectural and engineering 

firms. As that transition demonstrated, once a methodology or technological advance gains traction in 

the market, transformation can happen quickly. The 

first architectural drawing software for use on personal 

computers was released in 1982. Within 20 years of that 

release, most companies had invested in information 

technology staff and infrastructure to learn about and 

shift to the new technology. Today, there are dozens of 

architectural drawing software options and firms invest 

in the technology and trained staff to remain relevant 

and competitive. 

i

A Guide to Zero Energy 

and Zero Energy Ready 

K–12 Schools

Paul Torcellini and Kim Trenbath, NREL

Nathaniel Allen, U.S. Department of Energy

Maureen McIntyre, McIntyre Communications Inc.
Int

Similarly, ZE is a way of thinking about whole-building energy performance as well as a methodology for 

achieving specific energy targets in buildings. Just as 

design teams had to change workflows to adapt to CAD, 

achieving ZE may require modifying design and delivery 

processes. Making ZE standard practice is a paradigm 

shift for most school districts and building professionals, but owners and project teams can use the lessons 

learned from existing ZE projects as guides to develop 

their own cost-effective ZE schools (see CASE STUDIES, 

page 23). The growing number of ZE schools demonstrates that when owners and project teams adopt ZE 

goals and cost control strategies early in the process, 

costs can be comparable to or even less than conventional schools (see Small Decisions, Big Benefits: Warren 

County Public Schools, page 24, and Robust, Affordable 

K–12 Education: Arlington Public Schools, page 28). 

ZE is a way of thinking about whole-building 

energy performance as well as a methodology for 

achieving specific energy targets in buildings.

Zero energy can enhance students' educational experience. 

In 2017, Mr. Brandt's kindergarten class at Graceland Park/

O'Donnell Heights Elementary/Middle School in the inner 

city of Baltimore built a model of their new zero energy 

school with graham crackers and chocolate bars. The school 

opened in September 2020.

 Photos from Grimm + Parker Architects
10 RESEARCH RESULTS

RESEARCH RESULTS

Jennings Creek Elementary in Bowling 

Green, Kentucky, is the first zero energy 

school funded by a guaranteed energy 

savings contract. The agreement is between 

Warren County Public Schools and CMTA 

Energy Solutions and, over time, will finance, 

replace, and upgrade energy systems 

through project savings district-wide.

Photo from Sherman Carter Barnhart Architects, 

Chris Phebus Photography
RESEARCH RESULTS 11

Evaluating the belief that ZE schools are more expensive than conventional schools is important 

because the perception of risk alone can drive up costs (see Risk Management, page 22). 

Toward that end, researchers collected project cost, energy performance, and other data on 

approximately 150 K–12 schools around the United States. 

1 https://betterbuildingssolutioncenter.energy.gov/accelerators/zero-energy-schools

2 https://www.ashrae.org/technical-resources/aedgs/zero-energy-aedg-free-download

The Research

Most of the information came from presentations; public 

records; design firm websites; and personal communications with architects, engineers, school district personnel, and partners in the U.S. Department of Energy’s Zero 

Energy Schools Accelerator.1 The cost data have limitations in that different schools can have different boundary conditions. For most schools, land acquisition is not 

included in the project costs of the school; however, 

other items such as site infrastructure, school district 

administrative costs, and furniture may or may not be 

included in the reported project costs. 

Although data were collected on school renovations 

that resulted in a substantial reduction in energy use, 

the focus for this analysis was on new construction. The 

many differences between renovations and renovations 

plus additions make comparisons difficult. 

The data were normalized to average 2019 costs (last 

available) and to a fictitious location that represents the 

“average” construction cost location. When they were 

available, cost data were as of the bid date. If the bid 

date was not known, the occupancy date minus 2 years 

was used to establish the cost basis. Note that the year 

cost basis is a yearly value so a school that is occupied 

for August would have a construction time of between 

20 and 32 months. The original group of roughly 150 

U.S. schools was narrowed to 88 schools for which data 

on costs, projected or measured EUI, and location were 

available.

The Results

The school buildings included in Figure 1 are drawn from 

multiple sources, and were selected based on the 

availability of information. In addition, some of the EUIs 

are higher than the target EUI values established for ZER 

schools in the ZE K12 AEDG.2 Figure 1 shows the distribution of schools operating at EUIs of less than 

30 kBtu/ft2 ·yr and, although that is higher than the AEDG 

recommendations, it represents a significant savings 

compared with current energy standards. ZE and ZER 

schools have been built in urban and rural areas as well 

as in a variety of climate zones. 

Figure 1. The geographic distribution of the schools with energy use intensities less than or equal to 30 kBtu/ft2·yr

Number of Schools 

1 12
12 RESEARCH RESULTS

In Figure 2, the bubble sizes represent school size, with 

larger bubbles representing larger schools. The project 

cost data were plotted versus the EUI of the school. The 

orange line is the average cost of schools as reported 

in the State of Our Schools: America’s K-12 Facilities 20163

report. Average costs range from $205 to $495 per ft2 

and there is a set of higher-priced outlier schools with 

EUIs in the 20 to 30 range. Some other outliers are very 

small projects, often one or two classroom buildings on 

a school campus. Figure 2 includes schools in the sample 

set with EUIs of more than 30 kBtu/ft2·yr and demonstrates that school capital costs are independent of 

energy performance.

3 https://kapost-files-prod.s3.amazonaws.com/published/56f02c3d626415b792000008/2016-state-of-our-schools-report.pdf?kui=wo7vkgV0wW0LGSjxek0N5A 

Many of the ZE schools are less expensive than an average school and fall within a tight cost range. For most of 

the schools in this analysis, project costs are independent 

of EUI. Most districts are under considerable pressure to 

keep school costs under control and the process is public 

and transparent. School districts respond to public 

pressure and sometimes have state requirements that 

mandate school costs. Like all schools, ZE schools must 

be responsive to these cost pressures. A ZE school can 

help alleviate school districts' economic pressures, as the 

ZE schools built for less than conventional schools 

demonstrate (see CASE STUDIES, page 23).

Figure 2. Graph of project cost and energy use intensity for the 88 K–12 schools studied 

During the past 15 years, design strategies and building 

technologies have been refined to the point that school 

buildings can generate as much energy as they use with 

on-site renewable energy at costs comparable to or less 

than conventional schools. The energy efficiency progression is summarized in Figure 3.

A ZE school can help alleviate school districts' 

economic pressures, as the ZE schools built for less 

than conventional schools demonstrate.

The first Advanced Energy Design Guide (AEDG) for K–12 

schools demonstrated ways to achieve a 30% energy 

savings compared with ASHRAE Standard 90.1-1999. 

When the guide was updated to a 50% energy reduction, 

the basis was ASHRAE 90.1-2004. The ZE K12 AEDG is 

different from the 30% and 50% guides in that it does not 

reference a baseline. Rather, in the ZE K12 AEDG guide, 

ZE is an absolute goal. 

Range of

State Average

Costs

Average U.S.

School Cost

Bubble size is 

relative size 

of school

$0

$200

$400

$600

$800

$1,000

$1,200

0 10 20 30 40 50 60

Energy use intensity (kBtu/ft2·yr)

Project cost ($/ft2)
RESEARCH RESULTS 13

Figure 3. Comparison of U.S. average source energy use intensity data for K–12 schools compared to ASHRAE 

Standards and Advanced Energy Design Guides 

The ZE K12 AEDG guide establishes EUI targets, however, 

and these targets are 42% better than ASHRAE 90.1-

2016, which is a substantial improvement over ASHRAE 

90.1-2010 as the black line in Figure 3 indicates. As codes 

become more stringent, improvements in building 

performance are keeping pace as a result of continued 

innovation and technological advances; state-of-the-artbuildings continue to outperform building standards by 

40%–50%. 

Figure 4 includes the 52 projects (59% of the sample set) 

that have EUIs less than 30 kBtu/ft2·yr. Of these 52 

schools, 71% have EUIs less than 25 kBtu/ft2·yr. 

Figure 4. Site energy use intensities for the subset of K–12 schools in the sample set that have energy use intensities less 

than 30 kBtu/ft2·yr

180

160

140

120

100

80

60

40

20

0

Source Energy Use Intensity (kBtu/ft2•yr)

2012 CBECS

Education

90.1-2007 90.1-2010 90.1-2016 K-12 30%

AEDG

K-12 50%

AEDG

K-12 ZE

AEDG

Range is 

high/low for 

dierent 

climate zones

0

3

6

9

12

15

[5-10] [10-15] [15-20] [20-25] [25-30]

Number of Projects

Energy Use Intensity (kBtu/ft2·yr)
14 RESEARCH RESULTS

4 https://www.nrel.gov/news/program/2021/documenting-a-decade-of-cost-declines-for-pv-systems.html

Figure 5. Cost of photovoltaics for actual projects compared with average photovoltaics costs for U.S. commercial 

buildings (200 kW average size) and the percentage of building budgets required for photovoltaics sufficient to 

achieve zero energy

For a select number of projects (see Figure 5), the incremental cost of PV as a percentage of the project cost was 

available. Before 2011, the incremental cost of providing enough PV to match building energy consumption 

was more than 7% of total project costs. As project EUIs 

dropped—reducing the size of the PV array—the cost of 

PV has also dropped. The result is that the percentage of 

the total building budget required for PV has decreased 

more quickly than the reduction in PV costs. 

The incremental cost of adding PV to go from ZER to ZE 

is less than 3% for this collection of commercial buildings. This reduction in incremental cost can be attributed 

to design teams specifying PV early in the process and 

including infrastructure to easily incorporate the PV. It is 

also a result of dramatic PV cost reductions during the 

last decade.4

Now that the percent PV increases a building’s budget is 

smaller than a typical 5% cost estimating error, PV can be 

routinely included in most building designs as an add-alternate. This allows for inclusion if funds are available 

through the construction bidding process. An add-alternate list includes amenities or features offered to owners 

and the prices of those extras. Owners can then accept 

the features they prefer and can afford. If the bid comes 

in within the total ceiling, PV can easily be incorporated 

into the project.

Key Takeaways

The number of ZE schools designed and built on comparable or smaller budgets than local conventional schools 

is growing nationwide. Lessons learned from successful 

ZE school projects (see CASE STUDIES, page 23, for 

examples) include:

ZE and ZER schools are being built in a variety of U.S. 

climate zones and locations (see Figure 1, page 11). 

They are also being built in urban and rural communities. 

ZE schools need not cost more than conventional 

schools. When they do, it is a result of added amenities rather than energy efficiency or renewable energy 

upgrades.

0%

5%

10%

15%

20%

25%

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020

PV Installed Cost Compared to Project Budget

PV Cost ($/W)

Year

NREL Reported PV Average Cost ($/Watt)

Actual PV Costs

% Building Budget
RESEARCH RESULTS 15

The solar rooftop laboratory at Discovery 

Elementary School In Arlington, Virginia, 

is an example of how a zero energy school 

can enhance student learning.

Photo from VMDO Architects, Lincoln Barbour Photography

ZE schools can cost less than conventional schools. 

Energy efficiency improvements not only reduce ongoing operating costs but unlock synergies that reduce first 

costs (see Shifting Costs, page 18; Small Decisions, Big 

Benefits: Warren County Public Schools, page 24; Robust, 

Affordable K–12 Education: Arlington Public Schools, page 

28). 

The perception that ZE schools are expensive and 

risky alone can drive up costs. Project team members unfamiliar with ZE building or unconvinced of its 

benefits are likely to increase bids to cover unforeseen 

expenses.

The cost of a school does not correlate with energy 

consumption (EUI). This is confirmed by the scatter in 

the cost data (see Figure 2, page 12) and the lack of a 

link between cost and EUI as well as the instances of ZE 

schools that cost less than conventional schools in the 

same district (see Small Decisions, Big Benefits: Warren 

County Public Schools, page 24; Robust, Affordable K–12 

Education: Arlington Public Schools, page 28).

Design teams are becoming increasingly adept at 

designing very energy-efficient buildings. Skilled 

designers; improved energy efficiency technologies; and 

free, easily accessible design guidance5 (see Figure 3, 

page 13) could make ZE schools the rule rather than 

the exception. 

5 https://www.ashrae.org/technical-resources/aedgs/zero-energy-aedg-free-download

A fixed budget and firm EUI established early in the 

process are key. Setting a budget and an absolute EUI 

value—preferably in the low 20s or less—helps shift 

conversations from how much cost ZE will add to how to 

achieve ZE within the existing budget; these strategies 

can reveal energy and dollar savings that would otherwise be missed.

Many schools are currently operating with low EUIs. 

In the sample data set for this report alone, more than 

half the schools have an EUI of less than 25 kBtu/ft2·yr.

PV is so inexpensive that it can routinely be added 

to new schools. The cost of PV has dropped dramatically (see Figure 5, page 14) and the incremental cost 

of adding PV to a commercial building has fallen to less 

than 3% of the project budget in many cases.

ZE schools can relieve economic pressures on school 

districts. Because they have reduced operating costs 

and often even reduced first costs, ZE schools improve 

districts’ economic health.

Experienced ZE designers often prefer a performance-based design-build procurement process. The 

design-build process defines the rules early and determines best value for the owner through a competitive 

process; successful ZE schools are not solely dependent 

on the delivery method, however (see Robust, Affordable 

K–12 Education: Arlington Public Schools, page 28).
16 COST CONTROL

COST CONTROL

The zero energy bid for Discovery Elementary 

School in Arlington, Virginia, was $1 million less 

than the initial budget, making it possible to 

add solar photovoltaics and achieve zero energy 

within the budget. 

Photo from VMDO Architects, Alan Karchmer Photography
COST CONTROL 17

In conversations with architects, engineers, and school district officials working on ZE or ZER 

schools, innovations emerged that help contain up-front costs. The fact that ZE can dramatically 

reduce energy and operating costs over a building’s lifetime is a key benefit, but architects and 

engineers report that most clients are more interested in first costs.1 

1 https://www.nrel.gov/docs/fy19osti/72847.pdf

2 https://www.ashrae.org/aedg

That can make redirecting owners’ attention to life cycle 

or operating costs a hard sell, which puts pressure on 

project teams to reduce first costs as well as energy and 

life cycle costs. Fortunately, dramatic energy efficiency 

improvements such as those in ZE schools not only save 

energy and money but also unlock synergies that can 

reduce first costs (see Shifting Costs, page 18). Changing the conversation from “how much more will ZE cost” 

to “how can we achieve ZE within our budget” can reveal 

opportunities for energy and dollar savings that a more 

conventional approach would miss. 

Project teams have developed and refined the strategies discussed here during the process of designing and 

building existing ZE schools. Adopting these approaches 

can keep costs in line with conventional schools and 

reduce the perception that ZE schools are untested 

and therefore risky to the design team, contractor, and 

school district. The perception of risk alone can drive up 

costs because project team members will often increase 

bids to limit exposure (see Risk Management, page 22). 

Changing the conversation from “how much 

more will ZE cost” to “how can we achieve ZE 

within our budget” can reveal opportunities 

for energy and dollar savings that a more 

conventional approach would miss.

Establishing a Budget and 

Energy Goal

Establishing a fixed budget and setting an absolute 

EUI target at the outset of the project can take some of 

the uncertainty and attendant risk out of a ZE school 

project, especially for districts and project teams new 

to ZE and ZER buildings. Establishing an EUI goal is not 

standard practice for most building projects, even those 

characterized as “green” or “energy-efficient.” Typically, 

an energy use projection is calculated after the design 

is substantially complete, and energy performance is 

determined during the design process. In a ZE school 

project, however, energy performance drives the design 

process.

Establishing a fixed budget and setting an 

absolute EUI target at the outset of the project can 

take some of the uncertainty and risk out of a ZE 

school project.

Energy goals can be established and validated several 

ways. A good place to start is the ZE K12 AEDG.2 In this 

publication, computer models combined with actual 

building case studies were used to create energy goals 

for a ZER school. To establish the target EUI:

• Use the recommended values from Table 3-1, page 34, 

in the ZE K12 AEDG and demonstrate to stakeholders 

that the EUI targets are attainable by providing case 

studies of similar schools that achieved low EUIs (see 

CASE STUDIES, page 23).

• Determine whether the school will have specialty 

functions and add these uses to the energy total; 

examples include swimming pools, ice rinks, television-quality lighting for sports fields, laboratories, 

technical education centers, and spaces with higher 

energy and ventilation requirements.

• Adjust the EUI goal down whenever possible to 

achieve higher efficiencies, which will reduce the size 

and cost of the on-site renewable generation required 

to meet the building’s energy loads.

Any school can be ZE with a big enough PV system. 

Energy efficiency, however, reduces the size and cost 

of the renewable energy system, and provides benefits 

with or without solar, notably reduced operating costs 

(see Benefits, page 21). 
18 COST CONTROL

Shifting Costs

Rather than trying to sell clients on life cycle costs, seasoned ZE project teams break down costs to help owners understand how affordable a carefully designed ZE 

school can be. Here are few examples:

• As Kentucky’s Warren County Public Schools learned, 

geothermal heating and cooling can be more expensive initially, but it is much cheaper and easier to maintain over the long term.

• Improving the building envelope can reduce the size 

and cost of the geothermal or other heating, ventilating, and air-conditioning (HVAC) system; for example, 

an investment of $200,000 in Discovery Elementary 

School’s envelope first costs allowed a savings of about 

$500,000 in HVAC first costs. 

• Rather than spend $119,000 to upgrade all Discovery 

Elementary School’s windows from double to triple 

panes, engineers calculated it would cost just $9,000 

to keep the double-pane windows and increase the 

size of the solar system while maintaining the building’s ZE status.

Choosing a Procurement Process

The procurement process is the method used to purchase the goods and services required to design, construct, and operate a building. Most purchased items—

appliances or tools, for example—are complete, discrete 

units and the design, engineering, and manufacturing 

costs are built into the price. Procuring a building, however, is a highly involved, customized process involving 

many players. 

Procuring a ZE school on a conventional school budget 

requires an integrative design approach.3 This process 

considers each strategy, system, and component from 

the perspective of an overall ZE goal, namely achieving 

an EUI low enough that the building’s energy needs can 

be met with an on-site renewable energy system. 

There is no “perfect” procurement process, but the delivery method for a ZE school can be key to the success of a 

project. Design-bid-build, construction manager at risk, 

and design-build are examples of project delivery methods used to design and build schools.

3 https://www.nrel.gov/docs/fy19osti/72847.pdf

4 https://dbia.org/wp-content/uploads/2018/05/Primers-What-is-Design-Build.pdf; https://itd.idaho.gov/wp-content/uploads/Alternative-Project-Delivery-Workshop-2014-05-14.pdf; https://

www.aceee.org/files/proceedings/2018/#/paper/event-data/p313

Energy-related goals can be inserted into all three but 

incorporating energy goals is easier in some procurement processes than in others. For example, a performance-based design-build procurement process4

 

requires that the project team deliver a building that 

meets the energy and other performance-based goals 

for a firm fixed price. When the ZE goal and a firm budget 

are established early, the emphasis shifts from concerns 

about the cost of getting to ZE to determining how to 

achieve ZE within the budget. The project team is then 

free to explore creative approaches to energy and dollar 

savings that might be missed otherwise. 

Regardless of the procurement process, contracts for 

designers and contractors should clearly describe energy 

and other performance criteria. The request for proposal 

should not prescribe solutions to avoid placing unnecessary constraints on the designers and contractors. 

A better strategy for owners is to let the professionals 

develop innovative solutions within the constraints of 

the budget.

When ZE becomes a school goal, selection of the design 

and construction team should be based on qualifications 

and best value. When the budget is fixed, all the bids will 

be the same and the choice will come down to which 

team delivers the best value within that budget. 

For example, Arlington Public Schools used a designbid-build process for Discovery Elementary School in 

Arlington, Virginia (see Robust, Affordable K–12 Education: Arlington Public Schools, page 28). Thanks to an 

innovative design team, the ZE bids were $1 million less 

than the initial budget, making it possible to include a PV 

system to meet the ZE goal and still deliver the school for 

less than the original budget.

When the budget is not fixed in a design-bid-build 

procurement process, architects and engineers estimate 

construction costs during the design process and the 

building contractor does its own estimate based on 

historical cost data after the design is finalized. If the construction contractor’s estimate is higher than the designers’, the design is modified to meet the budget. 

This can jeopardize the ZE goal, because equipment 

included in the design expressly to meet energy goals 

may have higher up-front costs than less energy-efficient 

choices. Switching the energy-efficient options for less 
COST CONTROL 19

energy-efficient options to meet the budget can ruin a 

building’s chances of meeting its EUI targets, and, in turn, 

achieving ZE. School owners should be aware of these 

trade-offs and take steps to prevent energy efficiency 

compromises. 

Hiring a construction manager committed to controlling 

costs and meeting the ZE goal is one such step. The 

construction manager’s role is pivotal because subcontractors may not be familiar with ZE. Having an on-site 

ZE advocate monitoring progress and firmly rejecting 

changes that undermine the ZE goal can go a long way 

toward ensuring the success of the project.

A good design-build process also limits compromises 

because it defines all the rules in advance and determines the best value for the owner through a competitive process. This process can foster an environment that 

encourages open discussions about how to achieve the 

ZE goal and facilitate the process of identifying the team 

best qualified to successfully complete the project.

School district policies usually define permissible project 

delivery methods. Sometimes project teams can influence the decision, however, and team members committed to ZE goals may have strong opinions about process. 

One engineer put it bluntly, “If I could do every project 

using design-build delivery, I would.” 

Measuring and Verifying 

Performance

To ensure that the projected savings materialize, every 

ZE school should undergo a rigorous measurement and 

verification process.5 Some engineering firms pressure 

test every building. The envelope is critical to the sizing of the HVAC system, and a trend in ZE building cost 

control is to pay for additional envelope pressure testing, 

with the procedure outlined in the specification documents. By assuring envelope performance, the engineering team can downsize the HVAC to reflect the performance of the envelope that will actually be built.

The construction manager’s role is pivotal because 

subcontractors may not be familiar with ZE.

5 https://www.nrel.gov/docs/fy19osti/72847.pdf

6 https://www.dsireusa.org

7 https://www.nrel.gov/news/program/2021/documenting-a-decade-of-cost-declines-for-pv-systems.html

8 https://www.ashrae.org/aedg

As one engineer at a firm that guarantees building 

performance said, “If I know the envelope won’t leak, I’m 

comfortable downsizing the HVAC system.”

Acquiring a Solar System

The cost of PV has decreased dramatically, but some 

ZE schools are opting to enter into a power purchase 

agreement with a solar developer rather than purchasing 

the system outright. This arrangement has the advantage of not requiring additional capital for the PV system, 

and the district buys power from the solar developer 

at a lower price than the local utility rate. An additional 

advantage to the power purchase agreement model is 

that a private company can pass some of the tax benefit 

to the school, although that benefit will be decreasing in 

the coming years. 

In some places, incentives are available that make 

purchasing PV attractive (see the Database of State 

Incentives for Renewables & Efficiency®6 [DSIRE] for local 

incentives). For example, in Connecticut it makes sense 

to buy the PV system because the state will reimburse a 

significant percentage of the capital costs.

In locations where reimbursement is unavailable, however, private-party financing is an option because the 

financing party often qualifies for federal tax incentives. 

In addition, the incremental cost of adding PV to a commercial building has fallen to less than 3% of the project 

budget in many cases, considerably less than a typical 

5% cost estimating error. This is because the cost of PV 

has plummeted during the last decade7 and more design 

teams are specifying PV and designing infrastructure to 

accommodate the installation. As PV becomes increasingly affordable, owners and construction professionals 

can include PV routinely in all commercial building budgets or—at a minimum—as an add-alternative (for more 

detail, see Figure 5 on page 14 and the accompanying 

discussion).

School districts need to be cautious and educate 

themselves about solar pricing models, because utility 

demand charges or connection fees can impact the cost 

analysis. (DSIRE is an excellent source for local renewables and energy efficiency incentive programs. For more 

information on PV for ZE schools, see also the ZE K12 

AEDG,8 pages 191–201). It is worth noting that energy 

efficiency is always a good investment for school districts.
20 BENEFITS AND CHALLENGES

BENEFITS AND 

CHALLENGES

Jennings Creek Elementary School is part of an 

energy savings contract between Warren County 

Public Schools and CMTA Energy Solutions 

that guarantees the district annual savings of 

$842,753 in utility and operational costs.

Photo from Sherman Carter Barnhart Architects, Chris Phebus 

Photography
BENEFITS AND CHALLENGES 21

Evidence is mounting that the perception that ZE schools cost more is a myth and ZE schools 

can be built on budgets comparable to or even smaller than conventional schools. They also 

use far less energy; the median U.S. K–12 school has an EUI of 48.5 kBtu/ft2·yr1 and the target 

EUI of a new ZE school is usually less than half the national median. ZE schools are built using 

conventional materials, equipment, and tradespeople, and design, construction, and delivery 

processes have been refined to the point that a ZE school’s performance can be guaranteed. 

1 https://portfoliomanager.energystar.gov/pdf/reference/US%20National%20Median%20Table.pdf, page 2

2 https://www.vmdo.com/architecture-blog/bluestone-elementary-receives-livable-buildings-award/

Benefits

The benefits of adopting ZE goals in K–12 schools are 

becoming better understood. Here is a summary of ZE 

school benefits for districts, students and staff, and communities drawn from existing ZE K–12 schools.

School Districts

Energy is often a school’s largest expense after salaries, 

and over time, money saved on energy costs can be 

redirected to other priorities, including educational programs. The savings can be impressive. 

The architect for Jennings Creek Elementary School 

(see Small Decisions, Big Benefits: Warren County Public 

Schools, page 24), for example, estimates that Jennings 

Creek saves nearly $143,000 per year compared to a typical Kentucky elementary school. Including the revenue 

from selling solar-generated electricity back to the utility, 

the cumulative savings during the 20-year bond repayment period is expected to be nearly $3.7 million.

ZE schools have lower operations and maintenance 

costs because wall, window, and roof systems are more 

durable than standard construction. Simpler and more 

accessible HVAC systems also reduce the cost of upkeep.

In addition, very energy-efficient buildings make it easier 

for district officials to accurately predict energy costs. 

Investing in energy efficiency and renewable energy also 

locks in today's energy prices, providing a hedge against 

future utility rate increases. 

Students and Staff

ZE schools offer robust educational environments. 

They are living labs, with the building itself serving as 

a teaching tool. During design and construction, a ZE 

K–12 school focuses the school community (students, 

teachers, staff, and parents) on the process of achieving 

ZE. Once the school opens, sustainability is typically 

built into curricula and many schools have formal energy 

clubs and other mechanisms to engage students and 

staff in operating the building (see A Path to Energy Positive: Horry County Schools, page 30). This exposure to 

science, technology, engineering, art, and math (STEAM) 

subjects can prepare students for future STEAM courses 

or careers. 

ZE school occupants also report that their schools have 

exceptionally comfortable indoor environments. A new 

ZER school, Bluestone Elementary School in Harrisonburg, Virginia, was named the “Most Livable Building” 

in the United States by the University of California 

Berkeley’s Center for the Built Environment. Now in its 

thirteenth year, the Livable Buildings Awards recognize 

projects that demonstrate high occupant satisfaction, 

excellent design, and innovative operation strategies.2

This achievement is particularly notable because, 

although excellent indoor air quality is critical to a “livable” building, it can increase energy use. The Bluestone 

project team achieved its energy goals and created a 

building with exemplary indoor air quality.

Communities

Reduced energy consumption reduces the school district’s—and the community’s—exposure to the risk of 

energy price volatility. Because the cost of designing and 

building a school with a low EUI is comparable to that of 

a conventional school, it can be an indicator that local 

officials are exercising sound fiscal management.

ZE and ZER schools are healthy, well-lit buildings and, 

as a result, they may be used more than conventional 

schools. More occupied hours can result in more energy 

use, and project teams should factor in use patterns as 

they design schools to achieve ZE or ZER status.
22 BENEFITS AND CHALLENGES

ZE schools can also improve local resilience. A K–12 

school is often a community emergency shelter, and, 

because of energy-efficient design and daylighting, 

ZE schools can become safe and comfortable daytime 

refuges during extreme weather events and other grid 

outages. When battery storage is paired with the on-site 

renewables, a school can also maintain critical loads and 

comfort levels after the sun sets. 

Challenges

Although many of the technical barriers related 

to designing and building a ZE school have been 

addressed, these projects still face challenges.

The data collected indicate ZE school costs are 

usually comparable to and can be less than 

conventional schools. Further, when costs are 

higher, it is often a result of aesthetic, comfort, 

or other upgrades rather than the building’s ZE 

status.

Risk Management

During conversations and correspondence with educators and building professionals about ZE schools, the 

most-cited challenge by far was the perception that ZE 

schools are more expensive, and therefore risky, than 

conventional schools. The data collected for this publication indicate ZE school costs are usually comparable to 

and can be less than conventional schools. Further, when 

costs are higher, it is often a result of aesthetic, comfort, 

or other upgrades rather than the building’s ZE status. 

The perception of risk can become self-fulfilling. When 

a project team is unfamiliar with ZE building or unconvinced that such a facility can live up to the promise of 

its purported benefits, they are likely to increase their 

bids to account for unforeseen expenses. 

A related issue is the difficulty of getting to ZE with 

business-as-usual approaches to design and construction. Architects and engineers interested in ZE will have 

to invest in developing the skills necessary to produce 

successful ZE schools.

3 https://www.nrel.gov/docs/fy19osti/72847.pdf

4 https://www.hartfordbusiness.com/article/net-zero-energy-schools-offer-ct-a-glimpse-of-future-green-development

In a perfect world, key stakeholders would be involved in 

the planning process from the beginning, would adopt 

and commit to the ZE goal, and would consider the ZE 

goal in each design and construction decision. The reality is likely to be that the ease with which a ZE school can 

be delivered will be unfamiliar to the project team at first 

and that existing procurement and delivery mechanisms 

may need to be modified to get to ZE. As more school 

districts and design and building professionals become 

enthusiastic about and comfortable with ZE, they will 

have to be patient and persistent as they educate their 

colleagues and communities. 

If the design team is...not contractually obligated 

to meet a measurable, absolute EUI goal on a 

fixed budget, it could respond to cost increases 

and other challenges by arguing that ZE is not 

possible.

If the design team is unfamiliar with ZE and not contractually obligated to meet a measurable, absolute EUI goal 

on a fixed budget (see Establishing a Budget and Energy 

Goal, page 17), it could respond to cost increases and 

other challenges by arguing that ZE is not possible. 

Establishing an EUI goal and budget from the outset and 

choosing a design team with ZE experience or a willingness to learn the process can avoid these conversations.

School Governance and Funding

K–12 school-related decision making is local. Introducing 

a school district to ZE and ZER strategies involves outreach to a range of stakeholders, including school board 

members, administrators, members of the community, 

building professionals, and taxpayers.3 Any or all of these 

constituencies may be unaware or skeptical of the benefits of ZE.

Finding building professionals familiar with or willing 

to learn about ZE schools can also be a struggle, especially when building is booming. There is evidence that 

increased community interest in ZE is pushing design 

teams and construction professionals to take on these 

projects, however. Northeastern Connecticut, for example, now has two new ZE schools, largely as a result of 

public support.4
CASE STUDIES 23

The careful daylighting design at Discovery 

Elementary School in Arlington, Virginia, saves 

money on lighting energy while providing 

bright, inviting interior spaces. 

Photo from VMDO Architects, Lincoln Barbour Photography

CASE STUDIES
24 CASE STUDIES

Small Decisions, Big Benefits: 

Warren County Public Schools

Warren County is Kentucky’s fastest-growing county, 

and, in 2003, as part of an effort to serve its growing 

K–12 student population, Warren County Public Schools 

(WCPS) set a goal of saving $3 million in energy costs 

in 8 years. The effort began with simple, no-cost energy 

efficiency strategies like turning lights off in unoccupied 

spaces. As existing schools were renovated and new 

schools were planned and built, the district adopted 

other cost-effective energy efficiency measures and soon 

exceeded its goal, saving more than $4 million in less 

than 6 years.1

As energy efficiency lessons were learned and applied 

to new and renovated schools, the process was steadily 

refined. When Plano Elementary School in Bowling 

Green opened in 2007, it was Kentucky’s most energyefficient school, operating at an EUI of 26.8 kBtu/ft2

·yr. 

For context, at that time new conventional schools in 

Kentucky typically consumed 65 kBtu/ft2·yr.

1 https://www.hpbmagazine.org/content/uploads/2020/04/09F-Plano-Elementary-School-Bowling-Green-KY.pdf

2 https://www.hpbmagazine.org/content/uploads/2020/04/12F-Richardsville-Elementary-School-Richardsville-KY.pdf

3 https://livingbuilding.kendedafund.org/2017/04/11/net-zero-energy-schools-southeast/; total cost of PV system was $2.75 million, about $7.90/watt

Once Plano was operating, Mark Ryles, then facilities 

director for the Kentucky Department of Education, 

posed a question: “How would one design a net zero 

energy school and how much would it cost?”2 That question launched an effort that involved engineers, architects, state regulators, utility companies, school board 

members, school facility managers, and school staff, and 

resulted in the design and construction of Richardsville 

Elementary, the first ZE school in the United States.

Being the first is risky, but the risk was mitigated somewhat by funding from the American Recovery and 

Reinvestment Act of 2009 (ARRA) that allowed Kentucky 

school districts to hire energy managers and included 

a $1.36 million grant to WCPS that paid about half the 

cost of the PV system.3 Still, concerns persisted in some 

quarters.

“When Richardsville was in design, there was chatter 

about how much it was going to cost,” said Kenny Stanfield, the project architect. “Zero energy was all theory at 

the time, so there was lots of pushback.”

Richardsville Elementary, the first zero energy public school 

in the United States, operates at an EUI of 18.2 kBtu/ft2·yr, 

and produces more energy than it uses. Warren County 

Public Schools receives an annual refund from the electric 

utility of more than $30,000 for the excess generation. 

Photo from Sherman Carter Barnhart Architects, Joshua White, photographer
CASE STUDIES 25

In addition, the project team faced a constraint unique to 

Kentucky—the Kentucky Department of Education mandates the maximum cost of every school in the state. (For 

example, in 2021, the maximum cost is $262.70/ft2 for 

elementary schools, $265.78/ft2 for middle schools, and 

$274.69/ft2 for high schools.4) To get to ZE, the school 

budget would have to include the cost of PV. 

Energy modeling showed that a PV system large enough 

to offset the Plano EUI of 26.8 kBtu/ft2·yr would push 

Richardsville’s cost beyond the state-mandated maximum, even with the ARRA monies. Clearly, the project 

team had to revisit the design, reduce the EUI, and cut 

costs.

“We had an advantage in that we’d done all the schools 

for Warren County and we had tracked the lessons 

learned,” explained Stanfield. “On the Plano project—

prompted by our facilities folks and engineers—we went 

with geothermal heating and cooling and improved the 

building envelope to achieve a low EUI.”

Based on that experience, the district again used geothermal heating and cooling for Richardsville but chose 

insulating concrete forms (ICFs) for the exterior walls. ICF 

walls are well-insulated, contain thermal mass, reduce 

construction time, create a very tight building envelope, 

and resist winds of up to 250 mph. (Kentucky schools 

must be able to withstand 225 mph winds.) 

Jennings Creek cost $1.5 million less to build than 

the average Kentucky school and...saves more 

than $195,000 a year in energy costs compared to 

a conventional school.

“Geothermal is more expensive initially, but much 

cheaper over the long term,” said Mike Wilson, WCPS 

Facilities Director. “Districts have to decide between lowest first cost and the best long-term value for students 

and the community—for us, the choice was clear.”

Once Plano was operating, its low energy use caught the 

attention of the utility, the Tennessee Valley Authority, 

which installed meters to monitor energy end uses in the 

building. 

4 https://education.ky.gov/districts/fac/Pages/Property-Insurance.aspx, "Property Insurance Replacement Costs 2021"

5 https://www.hpbmagazine.org/content/uploads/2020/04/12F-Richardsville-Elementary-School-Richardsville-KY.pdf

6 https://www.scbarchitects.com/projects/jennings-creek-elementary/

“We had never measured anything except total building 

consumption, but the utility's meters allowed us to look 

at all the end uses, which was very useful.” said Stanfield. 

The project team used the metered data to guide decision making. The result was that Richardsville Elementary 

School, the first ZE K–12 school in the United States, 

opened in 2010, came in on budget including the PV 

system, and has operated at an EUI of about 18 kBtu/

ft2·yr ever since.5

WCPS’ latest ZE school, Jennings Creek Elementary, 

opened in 2018 and demonstrates what is possible when 

a district commits to ZE. Jennings Creek cost $1.5 million 

less to build than the average Kentucky school and had 

a design EUI of 17.5 kBtu/ft2·yr. The school is exceeding 

expectations—it operates at 15.5 kBtu/ft2·yr, and saves 

more than $195,000 a year in energy costs compared to a 

conventional school.6

According to Stanfield, the bottom line is that “from our 

little corner of the world, cost isn’t a barrier to ZE K–12 

schools.”

“From our little corner of the world, cost isn’t a 

barrier to ZE K–12 schools." 

— Kenny Stanfield, AIA, Sherman Carter Barnhart
26 CASE STUDIES

RICHARDSVILLE ELEMENTARY SCHOOL PROJECT DETAILS

Name Richardsville Elementary School 

Location Richardsville, Kentucky 

(9.3 miles north of Bowling Green, 

Kentucky)

Owner Warren County Public Schools

Building Type Elementary school; 

includes gymnasium and cafeteria

Occupants 460 students and 35 staff

Floor Area 72,285 ft2

Distinctions/Awards

First ZE K–12 school in the United 

States

American School & University, Special 

Citation, 2008 and 2011

Andromeda Award, Alliance to 

Save Energy (Warren County Public 

Schools), 2009

Total Cost $14,927,000 or $206.50/ft2

[2010 dollars]

Photovoltaic System Cost

$2.75 million

Substantial Completion/

Occupancy September 2010

Average Operating Hours per 

Week 45

ENERGY DETAILS

Annual Site Energy Use Intensity 

18.2 kBtu/ft2·yr

Electricity from Grid 18.2 kBtu/ft2·yr

Annual On-Site Renewable Energy 

Exported to Grid (from PV) 

17.8 kBtu/ft2·yr

Annual Net Energy Use Intensity 

0.39 kBtu/ft2·yr

Savings versus Standard 90.1-

2004 Reference Building 52.8%

Photovoltaic system 348 kW

PROJECT TEAM

Building Owner/Representative 

Warren County Public Schools, 

Tim Murley, Superintendent

Architect Kenny Stanfield, AIA 

Sherman Carter Barnhart

General Contractor 

RG Anderson Company, Inc.

Mechanical Engineer 

Mark Seibert, PE, LEED AP, CMTA, Inc.

Electrical Engineer, Lighting 

Design Brian Baumgartle, PE, LC, LEED 

AP, CMTA, Inc.

Energy Modeler Kosuke Kato, PE, 

LEED AP, CMTA, Inc.

Structural and Civil Engineer and 

Landscape Architect 

Sherman Carter Barnhart

KEY ZERO ENERGY 

FEATURES

ICF building envelope 

Solar photovoltaic system 

Geothermal water source heat 

pumps with a dedicated outdoor air 

system 

Daylight harvesting in classrooms, 

corridors, and public spaces

Right-sized HVAC with the savings 

used to enhance energy efficiency

Richardsville Elementary achieved zero energy 

with an extremely energy-efficient design and 

the addition of solar photovoltaics, including 

this rooftop system.

Photo by Rachel Paul Photography, NREL 18603
CASE STUDIES 27

JENNINGS CREEK ELEMENTARY SCHOOL PROJECT DETAILS

Name 

Jennings Creek Elementary School 

Location Bowling Green, Kentucky

Owner Warren County Public Schools

Building Type Elementary school

Occupants 650 students

Floor Area 88,469 ft2

Distinctions/Awards

Total Cost $18,400,000 or $208 ft2

Substantial Completion/Occupancy 

August 2018

ENERGY DETAILS

Annual Site Energy Use Intensity 

Design EUI of 17.5 kBtu/ft2·yr; operating 

at 15.5 kBtu/ft2·yr

PROJECT TEAM

Building Owner/Representative 

Chris McIntyre, Chief Financial Officer, 

Warren County Public Schools

Architect Kenny Stanfield, AIA, 

Sherman Carter Barnhart

General Contractor Alliance

Mechanical Engineer CMTA, Inc.

Energy Savings Performance 

Contractor CMTA Energy Solutions

KEY ZERO ENERGY 

FEATURES

ICF building envelope 

Superinsulated R-32 roof

350 kW solar photovoltaic system 

Geothermal water source heat pumps 

with a dedicated outdoor air system 

Right-sized HVAC equipment and 

use the savings to enhance energy 

efficiency

LED lighting

Passive daylighting controls and 

strategies

Geothermal HVAC

Efficient kitchen strategies—

eliminated type 1 hood

Occupancy, motion, and CO2

monitoring

Jennings Creek Elementary School earned the 

distinction of being Kentucky's most energy-efficient 

school through, among other things, an insulated 

concrete form building envelope; geothermal heating, 

ventilating, and air conditioning; and LED lighting. 

Photo from Sherman Carter Barnhart Architects, Chris Phebus Photography
28 CASE STUDIES

Robust, Affordable K–12 Education: Arlington Public Schools

7 https://www.nrel.gov/docs/fy17osti/68774.pdf

8 https://www.nrel.gov/docs/fy17osti/68774.pdf

Like Warren County Public Schools in Kentucky, the 

Arlington [Virginia] Public Schools (APS) ZE journey was 

the result of many people making decisions that built 

on the work of others. APS wanted to create the best 

possible learning environments for students. Toward that 

end, the district looked into integrating environmental 

stewardship during the planning process for Discovery 

Elementary School and explored other school projects 

that could serve as models.

One they looked at was Manassas Park Elementary, an 

energy-efficient school in nearby Manassas, Virginia. 

Wyck Knox, principal at VMDO architects, had been the 

project architect and manager on that project. Impressed 

by its success, APS officials asked Knox to “give us one of 

those but make it better.” 7

Knox hadn’t designed a ZE school, but he knew it was 

possible because it had been done at Richardsville Elementary in Bowling Green, Kentucky. 

“Richardsville didn’t have a lavish budget, but it did have 

an innovative engineering team,” Knox said. 

He realized the project would take his firm out of its 

comfort zone, energy performance would have to be 

a central focus, and it would be important to measure 

building energy use regardless of where the data landed. 

Discovery’s budget was fixed and had been established 

to achieve LEED Silver®, but the project team examined 

the original budget and proposed a ZE school as a competitive advantage to win the job. Although they had not 

done a ZE design, by examining the practices of others 

and maintaining their determination to change how 

schools are designed, the team developed the successful 

ZE design. 

School board members were intrigued but assumed the 

PV system required to get to ZE would break the budget. 

Still, they approved the project as a ZER building and 

decided to bid the solar system as an add-on.

When the ZE bids came back at $1 million less than the 

initial budget, John Chadwick, APS Assistant Superintendent of Facilities and Operation, explained to district 

officials that even without the solar system, Discovery 

would be “the most energy-efficient building in the system.” Because the school was under budget even when 

the PV system was included, however, the board decided 

to make Discovery a ZE school.8

Completed in 2015, the bids for Discovery Elementary 

School in Arlington, Virginia, came in at $1 million less then 

the original budget, making it possible to add solar 

photovoltaics and achieve zero energy within the budget.

Photo from VMDO Architects, Digital Design & Imaging Service Inc.
CASE STUDIES 29

DISCOVERY ELEMENTARY SCHOOL PROJECT DETAILS9

9 https://www.nrel.gov/docs/fy17osti/68774.pdf, https://www.youtube.com/watch?v=2kTS4UODWwc, https://www.aia.org/showcases/71481-discovery-elementary-school-Name

Name Discovery Elementary School 

Location Arlington, Virginia

Owner Arlington Public Schools

Building Type Elementary school

Occupants 630 students, 715 total

Floor Area 97,588 ft2 

Distinctions/Awards

2017 AIA Committee on the 

Environment (COTE) “Top Ten” 

recipient, zero energy certification 

from the International Living Future 

Institute 

Verified ZE building certified by the 

collaborative partnership of the 

International Living Future Institute 

and New Buildings Institute

Total Cost $33,391,000 or 342.16/ft2

Project Budget $36,000,000

Substantial Completion/

Occupancy September 2015

Delivery/Procurement Method 

Design-bid-build

ENERGY DETAILS

Annual Site Energy Use Intensity 

14.7 kBtu/ft2·yr

PROJECT TEAM

Building Owner/Representative 

John Chadwick, Assistant 

Superintendent, Facilities and 

Operations, Arlington Public Schools

Architect Bob Moje, Principal-inCharge; Wyck Knox, Project Architect

General Contractor 

SIGAL Construction

Mechanical, Lighting, Zero Energy 

Design Engineer CMTA, Inc.

Power, Plumbing, Fire Protection 

Engineer 2rw Consultants

Structural Engineer Fox + Associates

Civil Engineer Bowman Consulting 

Group, Ltd

Landscape Architect Oculus

Traffic Toole Design Group

Construction Manager Heery 

International

KEY ZERO ENERGY 

FEATURES

Ground source heat pumps, 

dedicated outdoor air delivery, CO2

sampling for controlling ventilation 

air, and energy recovery 

ICF walls, high efficiency glazing, and 

exterior window shades 

Energy-efficient laptops 

Daylight switching zones with 

dimmable LED lighting 

Dimming controls in classrooms and 

offices 

Thermostats per heat pump zone 

Roof-mounted photovoltaics 

Type 2 cooking hoods and watersource refrigerators 

Custom energy dashboard and 

educational solar lab 

Discovery Elementary, a zero energy 

school in Arlington, Virginia, came in 

under budget even when the PV system 

was included, and provides a robust 

learning environment for students. 

Photo from VMDO Architects, Lincoln Barbour Photography
30 CASE STUDIES

A Path to Energy Positive: Horry 

County Schools

Horry County Schools in South Carolina opened three 

new ZE schools in 2017 and two in 2018. The five 

schools, Ten Oaks Middle School, St. James Intermediate School, Socastee Elementary School, Myrtle Beach 

Middle School, and Socastee Middle School, are similar 

designs—two stories with an atrium, a hybrid geothermal system, daylighting, LED lights with control systems, 

a PV system on the roof, and a goal of producing 10% 

more energy than they use. 

The district goal was an energy-efficient, high-performance school that generated more energy than it used 

and provided a collaborative learning environment. 

Achieving energy positive status involved reducing the 

energy demands of the building and installing PV to 

generate electricity that is used in the building as well 

as sold to the local utility. The school board used the 

same design-build team for all five projects to ensure 

consistency and replicability while maintaining the focus 

on achieving ZE. Horry County Schools learned valuable 

lessons during the design, construction, and operation of 

these schools.

Allow enough time to evaluate building performance. Horry County used a design-build procurement 

process that included a 3-year performance contract. The 

contract requires that the design-build team optimize 

the building’s operation and demonstrate that the ZE 

goal has been achieved. 

Contract directly with an independent commissioning agent and an independent firm that provides 

test and balance services early in the design process. When these professionals are at the table from 

the beginning of the project, there are opportunities to 

review systems and identify small problems before they 

become big problems that can be time-consuming and 

expensive to correct.

Research local utility rate structures and buy/sell 

arrangements for distributed PV early in the design process. Once the building is using the least possible energy 

to operate—the new Horry County schools have design 

EUIs of 22 to 23 kBtu/ft2·yr—that energy must come from 

the on-site PV system to achieve ZE. In Horry County, 

however, the district buys electricity for $0.17 to $0.18/ 

kWh and sells the PV output for $0.03 to $0.04/kWh. In 

addition, the utility only allows the schools to use 25% of 

the electricity the PV systems produce in the buildings 

and utility demand charges further erode energy savings. 

Use submetering and other strategies to monitor 

how and when energy is used. Until energy storage 

is affordable and commonplace enough that it can be 

used to reduce demand charges, it is critical that building owners and operators know specifically how much 

energy the building is using and when that use occurs. 

This information can help operators reduce or avoid 

demand charges by shedding loads and shifting flexible 

and controllable loads to minimize their utility bills and 

optimize the solar resource when it is available. Most 

ZE buildings today do not have energy storage, which 

means a building would be more likely to achieve ZE or 

energy positive status in a regulatory environment in 

which the utility bought the output of the renewable 

energy system at or near retail rates and building operators could control demand charges with load shifting. 

If utility billing rate and usage issues are not understood 

and evaluated early in the design process, the building 

could meet or even exceed its energy goal but still not 

achieve its anticipated energy cost savings.

A lesson learned from St. James Intermediate School and 

the other Horry County energy positive schools built from 

2017–2018 is to research local utility rate structures and 

energy purchase and sales practices early in the process.

Photo from Horry County Schools
CASE STUDIES 31

ST. JAMES INTERMEDIATE SCHOOL PROJECT DETAILS

12 https://www.horrycountyschools.net/domain/3010

13 https://www.sfla.biz/two-horry-county-schools-honored-with-architectural-and-interior-design-awards/

Name St. James Intermediate 

School

Location Myrtle Beach, South 

Carolina

Owner Horry County Schools

Building Type Intermediate school 

(grades 5–6)12

Occupants 870

Floor Area 170,918 ft2

DISTINCTIONS/AWARDS

American School & University, 

Educational Interiors August 2018 

Issue, Outstanding Design, St. James 

Intermediate School

2018 ENR Southeast Best Project in 

the K–12 Education Category, Horry 

County Schools

South Carolina A4LE Excellence in 

School Building and Design Honor 

Award

Learning By Design, Grand Prize and 

Outstanding Project awards13

Total Cost $47,700,000 or 279/ft2

Substantial Completion/

Occupancy August 1, 2017

Delivery/Procurement Method 

Design-build

ENERGY DETAILS

Annual Site Energy Use Intensity 

14.3 kBtu/ft2·yr

PROJECT TEAM

Building Owner/Representative

Rick Maxey, Ph.D. Superintendent, 

Horry County Schools

Architect of Record

SfL+a Architects

Designer-Builder SfL+a Architects

Interiors Architect Stantec

Exterior Architect 

Mozingo+Wallace Architects

KEY ZERO ENERGY 

FEATURES

Concrete stores latent heating or 

cooling energy

Centralized HVAC

Solar PV

LED lighting

Enhanced building automation

World class indoor air quality

Superior building envelope

Monitoring-based commissioning

Advanced building analytics post 

construction

Engage students, teachers, and facilities staff in the 

operation of the building. Horry County is using staff 

support and on-site mentoring to form and maintain 

an EnergyWise (Wisdom Is Saving Energy and the Environment) club at each school. EnergyWise is a program 

developed by EDUCON Educational Consulting, Inc.10 

The district is also using information and resources from 

the National Energy Education Development (NEED) Project,11 including NEED energy science kits and the opportunity to participate in the Youth Achievement Awards 

10 https://educonenergy.com/about/

11 https://www.need.org

competition, to develop teacher curricula and support 

student energy clubs and other energy activities.

The new Horry County Schools came in at a 10% to 15% 

cost premium. According to Robbie Ferris, Firstfloor and 

SfL+A Architects CEO, however, the buildings were more 

expensive because “they include aesthetic upgrades, not 

because it costs more to get to ZE.”

St. James Intermediate School in 

Myrtle Beach, South Carolina, is one 

of five energy positive schools built in 

the district from 2017–2018. 

Photo from Horry County Schools
32 CONCLUSIONS 

St. James Intermediate School in Myrtle Beach, 

South Carolina, which opened in August 2017, 

serves fifth and sixth graders and has a goal of 

producing 10% more energy than it uses. 

Photo from Horry County Schools

CONCLUSIONS 
CONCLUSIONS 33

The findings of this research indicate that pursuing ZE in K–12 schools does not have to increase 

design and construction costs and some ZE schools cost less than conventional schools. 

1 https://www.ashrae.org/aedg

Design teams that have achieved ZE have identified 

approaches that help avoid the challenges and optimize 

the benefits, notably: 

• Establishing a budget and energy goal early in 

the process and considering the budget and ZE goal, 

expressed as an EUI, in every design decision, contract, 

and construction document; in short, make energy 

performance a major driver of the design and construction process

• Shifting costs by using integrative design to offset 

increased costs in one area (the building envelope, for 

example) with cost savings in others (the HVAC system, for example); the result can be reductions in both 

life cycle costs and first costs, a major focus for most 

school districts

• Choosing procurement and construction management processes that can get the project to ZE; 

although there are no perfect processes, a well-executed performance-based design-build strategy and a 

committed ZE construction manager can lock in a ZE 

goal and a fixed budget early in project development 

and provide cost control

• Measuring and verifying performance to ensure that 

the building operates at ZE during its lifetime; include 

input from measurement and verification professionals early in the project and design in approaches to 

educate students, replacement staff, and new teachers 

about how the building operates and how everyone 

can be involved in maintaining its ZE status

• Acquiring a PV system to get to ZE can be complicated by utility demand charges, connection fees, and 

pricing for electricity fed back to the grid; districts can 

choose among a number of acquisition options, from 

power purchase agreements to owning the system 

outright.

Creating strategies for implementation is important to 

the success of ZE school projects. A checklist for success 

could create a preliminary framework for the routine 

design and delivery of ZE schools. Items on that list 

might include:

• Adding language to building procurement documents 

requiring a ZE goal; further, requiring that building 

energy use not exceed the recommendations in the ZE 

K12 AEDG1

• Questioning potential project design teams about 

their track records creating buildings that achieved 

energy goals, especially a ZE goal

• Requiring that—at a minimum—a PV system be 

included as an add-alternate in any bid package.

St. James Intermediate School is one of five 

energy positive schools built from 2017–2018 

in Horry County, South Carolina, that used a 

design-build procurement process.

Photo from Horry County Schools
ACRONYMS

1 https://basc.pnnl.gov/resource-guides/insulated-concrete-forms-icfs

2 https://www.nrel.gov/docs/fy19osti/72847.pdf

3 https://www.energystar.gov/buildings/benchmark/understand_metrics/source_site_difference

4 https://www.energystar.gov/buildings/benchmark/understand_metrics/source_site_difference

EUI energy use intensity

HVAC heating, ventilating, and air conditioning

PV solar photovoltaics

ZE zero energy

ZE K12 AEDG Advanced Energy Design Guide for K–12 Buildings: 

Achieving Zero Energy

ZER zero energy ready

GLOSSARY

energy use intensity. The energy consumption of a building, expressed 

in thousands of British thermal units per square foot per year (kBtu/ft2·yr).

insulating concrete forms.1 A building system, abbreviated as ICFs, that 

uses rigid foam insulation, steel reinforcement, and poured concrete to 

construct sturdy, continuously insulated walls.

integrated design.2 A design strategy that considers each strategy, system, and component from the perspective of an overall energy consumption (EUI) goal low enough that the building’s energy needs can be met 

with an on-site renewable energy system.

site energy use intensity. A building’s energy consumption at the site.3

source energy use intensity. The total amount of raw fuel required to 

operate a building, including all transmission, delivery, and production 

losses.4

zero energy. A building with an energy use intensity (EUI) low enough 

that its energy needs can be met with an on-site renewable energy system, usually solar photovoltaics.

zero energy ready. A building with an energy use intensity (EUI) low 

enough that its energy needs could be met with an on-site renewable 

energy system and that has the infrastructure in place to support the 

renewable energy system, but whose owner has opted to delay the installation for budget or other reasons.
APPENDIX A: ZERO ENERGY 

SCHOOLS ACCELERATOR

The Zero Energy Schools Accelerator,1 launched by the U.S. Department of Energy in the fall of 2016, was a 3-year 

effort to identify, develop, and share strategies for achieving ZE in K–12 schools. Participants included 10 partner 

school districts, 3 states, and 11 nongovernmental organizations (see Zero Energy Schools Accelerator Participants for details). The National Renewable Energy Laboratory provided technical support.

ZERO ENERGY SCHOOLS ACCELERATOR PARTICIPANTS

1 https://betterbuildingssolutioncenter.energy.gov/accelerators/zero-energy-schools

Implementing Partners 

Adams 12 Five Star Schools (CO), Shannon Oliver 

Alexandria City Public Schools (VA), 

Azjargal Bartlett 

Arlington Public Schools (VA), John Chadwick & 

Cathy Lin 

Baltimore City Public Schools (MD), 

Joanna Pi-Sunyer

Boulder Valley School District (CO), Jeff Medwetz 

[State of] California, Department of General Services, 

Division of the State Architect, 

Chester Widom, Ida A. Clair 

Douglas County School District (CO), Wayne Blazek 

Hermosa Beach City School District (CA), 

Nancy Bartolo 

Horry County Schools (SC), Mark Koll

Los Angeles Unified School District (CA), 

Christos Chrysiliou & team 

[State of] Maryland, Maryland Energy 

Administration, Rory Spangler

[State of] Minnesota, Department of Commerce, 

Division of Energy Resources, Lindsay Anderson

San Francisco Unified School District (CA), 

Nikolai Kaestner 

National Partners 

Association for Learning Environments (A4LE), 

Donna Robinson 

Collaborative for High Performance Schools (CHPS), 

Elizabeth Krautscheid 

Geothermal Heat Pump National and International 

Initiative (Geo-NII), Jack DiEnna 

National Association of State Energy Officials (NASEO), 

Ed Carley 

National Energy Education Development Project (The 

NEED Project), Karen Reagor 

New Buildings Institute (NBI), 

Amy Cortese & Reilly Loveland 

North East Energy Efficiency Partnerships (NEEP), 

John Balfe & Carolyn Sarno 

Rocky Mountain Institute (RMI), 

Jacob Corvidae & Matthew Jungclaus 

Southern California Edison (SCE), 

Jerine Ahmed 

The Energy Coalition (TEC), Marc Costa

U.S. Department of Education, Andrea Falken 
Socastee Elementary School in Myrtle Beach, South 

Carolina, produces more energy than it consumes thanks 

to comprehensive energy efficiency measures and solar 

photovoltaics. 

Photo from Horry County Schools

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GOLDEN, CO 80401

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Operated by the Alliance for Sustainable Energy, LLC

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