In our GBA guest blog on August 26th , and our Net Zero Energy Vermont blog, we posed a question concerning net zero (NZ) statistics and metrics.

What are the metrics that will move us toward our net zero goal and future?

When we purchase a car we generally know what the fuel mileage is. When we buy, own, renovate or build a new building there isn’t a simple metric to compare buildings. To accomplish this goal the critical questions are:

  • How do we compare different sized buildings?
  • What is a simple and easy standard that is as intuitive as miles per gallon so it is understandable, applicable and useful?
  • What is the typical energy consumption?
  • How do we compare different building occupancies and uses (like office, residential, retail, dining)
  • What is a standard that is appropriate for a net zero building?

To compare different sized buildings we can total annual energy consumption and divide by the size of the building. This metric is called energy use intensity or energy utilization index (EUI).  For a step by step method to accomplish this, you can use this EUI Calculator that we’ve developed.  This resource can also be found through the Maclay Architects Resources page on our website.


We can benchmark typical existing building EUI’s by checking the EPA Commercial Building Energy Consumption Survey (CBECS) data at We can estimate typical new code complaint building EUIs. Also, ten US cities have required that large commercial, institutional, and residential projects disclose their EUIs, so those can be used for comparison.

02.02_EnergyConservationStandards copyFor net zero buildings we can establish recommended EUI metrics. For cold climates, the chart shown here identifies our recommended EUI metrics for net zero ready (NZR) buildings and compares them to existing and code compliant buildings without excessive process loads like kitchens, manufacturing, labs, etc.

This benchmark, metrics, and goal process is not perfect. It does not fully account for density of use, different building occupancies, capacity of people served and other variables. It is a metric that buildings can be designed to and then measured with past occupancy monitoring. Comments on our recent GBA article (Aug. 26) have offered useful considerations. Related to that, in Chapter 2 of The New Net Zero we have also offered additional considerations. However, in summary, we think EUI most effectively serves the need to have a simple, comprehensive, and easy metric that is similar to gas mileage for cars that can be implemented and used today to move toward a net zero world and future.


We are alive at a unique and remarkable time – this moment in history marks one of the most major changes in
human civilization.  Today, fossil fuels no longer make economic sense.  We have reached the tipping point where using renewable energy costs less than using fossil fuel energy.  This cost consideration even excludes the externalities and negative monetary effects of climate change and environmental issues from using fossil fuels.  Yet this is still a secret for most people, and there is an opportunity to make the shift now.

Five reasons why net zero buildings are affordable today:

1)      Renewable Energy Costs:

Renewable energy is less expensive (and less volatile) than fossil fuel energy.  With Power Purchase Agreements (PPAs), we can be using renewable energy with NO capital outlay and with energy prices equal to or less than fossil fuel and nuclear energy.

2)      Energy Conservation Costs:

We can build very high performing buildings that we call net-zero-ready for $5-$10 per square foot additional cost

3)      Advanced Heat Pump Technology:

New air-source heat pump (ASHP) technology provides reduced operating costs compared to fossil fuels, including cheap natural gas.  While capital costs are more for ASHP systems, leasing programs offer options to reduce the initial capital requirements.

4)      Low Interest Rates:

Envelope efficiency, heat pumps, and even renewable energy systems, can offer higher than 10% return on investment, particularly given the current low interest rates and the rising costs of fossil fuel energy.

5)      Lowest Operating Costs:

The bottom line is reduced cash outflow when combining cumulative energy and financing costs of net-zero-ready buildings over code-compliant buildings.   Simply put, it saves you money!!



The International Living Futures Institute, the parent organization for the Living Building Challenge, hosted an “unConference” on May 23rd  Portland, OR.   Among the highlights, Maya Lin, renowned international architect, and Lance Hosey the author of The Shape of Green: Aesthetics, Ecology, and Design both spoke.  I presented as a part of a panel with Mark Biedron, the co-founder of the Willow School and Marcus Sheffer of 7Group.  Our session “Exploring an Integrated Path to Replicable Net Zero Energy Projects” used our recent work as the net zero envelope architect at the Willow School’s new Health, Wellness and Nutrition Center as a case study to highlight the integrated design process and provide recommendations for replication on prospective Living Building and net zero projects.  We highlighted the specific challenges of net zero energy projects in cold climates and potential challenges with red list materials and the creation of beautiful and inspiring buildings. This project is currently under construction and on track to become a Living Building.  As a part of this project we supported a larger team led by Farewell Architects, the Architect of Record.  We served as a consultant for the Willow School directly and are the net zero envelope architect for the project.

More on Living Building Challenge and the unConference

Living Building Challenge was launched in 2006 and registered projects have grown to 201 in twelve countries by the time of the conference.  All of these buildings are required to be net zero energy to meet the LBC.  One of these projects is the Health, Wellness and Nutrition Center at The Willow School in Gladstone, NJ. The conference, or unConference, rather, was a great experience to learn about innovative approaches and projects related to the Living Building Challenge, share our experiences and recommendations for success with Living Building projects as well as a wonderful opportunity to meet other great thinkers and do-ers in the field and across the country. It is an inspiring and energizing event sharing experiences and expertise with some of the most leading edge energy and ecologically focused projects on the planet.


On May 14th Bill and I attended the 24th annual Vermont Businesses for Social Responsibility’s Spring Conference in Burlington, VT.  Bill presented as a member of an afternoon panel session titled “Nature’s Inspiration: Biomimicry and Biophilia as a Powerful Business Tool”.  Other members of the panel included Dr. Stephen Kellert, Sarah-Lee Terrat, and Michael Dupee.  Together the panel painted a picture of the multiple facets of incorporating biophilic design into buildings, workspaces, and products.  The discussion focused on the wisdom and inspiration that we can find in nature to inspire and inform design solutions for today’s evolving workplace; creating spaces that nurture, engage, and enliven humans.

VBSR Panel SessionFour points of view

During the panel session, Steve Kellert, Tweedy Ordway Professor Emeritus of Social Ecology and Senior Research Scholar at the Yale University School of Forestry and Environmental Studies, introduced the essential principles of biophilic design with national examples, including Herman Miller, Genzyme, and Google. As the leader in the field of biophilia, his introduction was reinforced by the other panelists’ work and examples. Bill shared Vermont-based examples of our office which employ biophilic design, including the George D. Aiken Center and Seventh Generation Headquarters both in Burlington, and Renewable NRG Systems’ offices in Hinesburg. Artist Sarah-Lee Terrat  described details of artistic representation of natural themes within buildings. She shared how she finds inspiration in nature and brings that to bear in her work which celebrates these biophilic themes and connections.  Michael Dupee, Vice President of Sustainable Innovation at Green Mountain Coffee Roasters, Inc, provided an introduction to biomimicry practice and related applications for businesses.

More on biophilia

For additional information on the topic please refer to our previous post, Finding Harmony: Biophilic Design & Environmental Design – which defines the term and provides further discussion on the need for biophilic design in our built environments.

Sustainable business enterprise

In addition to the afternoon panel session, our work was highlighted by keynote speaker, Alisa Gravitz, the Green America CEO and President.  Her talk praised local businesses in sustainable enterprise, products, and services.  She specifically cited Maclay Architects as an example and leader in the green building movement.

Maclay Architects also donated table space to the Vermont Energy Education Program (VEEP), who had a bike on hand to demonstrate energy required to power CLF, incandescent, or LED light bulbs.  The attendees were shy to use the bike, but eager to talk about energy efficiency, and we were thrilled to have VEEP as a booth collaborator.  While staffing our booth, I had many great conversations with attendees and talked extensively about office environments and creative options for work spaces showing examples from our work.

booth photo_Chris Prado Photo by Chris Prado, VBSR Intern

Overall, it was a beneficial conference with rich discussion and interesting presentations and interactions throughout the day.  We are proud to be involved with VBSR, who continues to organize and draw energetic, inspirational, and innovative leaders to their annual spring conference.


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New Net Zero: Explaining the hiatus

May 27, 2014

While I’ve been absent from the blog scene lately, I’m excited to be back and re-energize our team’s online writing efforts. During my blog hiatus I’ve been far from relaxed and “on-break” — instead I’ve written a book, The New Net Zero, which will be released this June by Chelsea Green Publishing!  The book effort, […]

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Finding Harmony : Biophilic Design & Environmental Design

October 25, 2011

A recent screening of an in-progress film, The Architecture of Life by Stephen Kellert and Bill Finnegan at the Yestermorrow School in Waitsfield, Vermont, started me thinking about the connection — or more possibly the disconnection — between biophilic design and environmental design. The former focuses its efforts on the user, attempting to provide a […]

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Net-Zero Building Design Comes to Maine

September 13, 2011

On a sunny day in July, I was happy to find myself in Boothbay, Maine for the grand opening of our most recent net-zero project, The Bosarge Family Education Center at the Coastal Maine Botanical Gardens. Heralded by the press as “The Greenest Building in Maine”, this educational center is the first net-zero commercial/institutional project […]

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Net-Zero: Lessons from the Field

July 20, 2011

I recently had the chance to travel to Montreal and present one of our Vermont projects, the net-zero Putney School Field House, at the international ASHRAE conference. This was an exciting chance for us to share with others how it really is possible to achieve net-zero in the cold climate of Vermont. This was also a […]

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Building Energy Statistics – Do they make sense?

November 29, 2010

Image via Wikipedia There are many measures used for building energy efficiency: total kBtu, kBtu/sf/yr, kWh/yr, therms/yr, kWh/sq.m/yr, $/yr or kBtu/person, and more. But determining when to use which metric, and even more importantly, how to make sense of a comparison of the energy efficiency of two different buildings, is no easy task. An Example […]

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Net-Zero Energy Buildings: Semantic Antics

October 26, 2010

Is obfuscation one of your goals? I didn’t think so. It does seem to be a goal in many architectural, energy efficiency and sustainability circles though. The terms zero energy building, net-zero carbon, net-zero energy cost, zero net energy, net-zero energy site, net-zero electricity, near net-zero, and net-zero ready…are all tossed about to describe a […]

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