Archive Of The Category ‘zero net carbon‘


Back in the Swing!

girl sitting on swing

Image via Pexels


It’s been a bit more than a year since I posted, and what a year it’s been! Besides all the global madness, I moved last July from Pacifica to Petaluma, California. I love it here and feel a bit like that girl on the swing. Life is good. Notwithstanding — you know. These are exciting times, change is afoot, and I still have faith that I’ll see great things happen in my lifetime.

I have three things to share today:

  1. Team Zero’s annual residential zero energy/zero carbon inventory is ON, for the 5th time! Add new projects or provide updates about projects you’ve inventoried before, HERE. We’re especially excited to learn more about what’s powering North American zero energy homes: what’s the mix of sun, electricity from the grid, and fossil fuels? Help us find out, so we can report on this to you all in the fall!
  2. With my dear friend and co-conspirator, Peter Yost, I’ve started a monthly blog series on Green Building Advisor. (It’s behind a paywall, but there’s a free trial available, and/or you can subscribe monthly — and GBA is a great resource, in case you don’t already know that.) Pete and I call the series “Building Bedrock,” but GBA uses the more sedate title of “Best Practices.” It’s a ton of fun. Each month Pete and I take on a new theme and expound on it from our unique perspectives. You get to see where we converge and diverge. So far, we’ve posted an intro and Part 1 (“Setting Priorities”), with nine more in the works. Beam in on the third Thursday of each month for the next installment.
  3. My esteemed colleagues at Zero Energy Ready Oregon have put out a new online resource, “Cost Effective Steps to Zero.” It’s a nice overview with clear illustrations and simple steps. This is a good introduction to the topic for novice audiences, and includes lots of links to deeper dives (including several of my publications, I’m happy to add).

Happy Solstice Week, my friends!

New ZNE Homes Resource

Congratulations to author Ed Dean and the team at Southern California Edison for their new publication, Zero Net Energy Case Study Homes, Volume 1 — and to all the project teams whose work it describes!

My favorite thing about the book is that, with just five case studies, it demonstrates that ZNE performance is achievable across a wide spectrum of housing types: new single-family homes (the easiest), a single-family renovation, a modestly-sized modular home, single-family production-built homes, and new multifamily housing.

Here’s an excerpt from my foreword:

Members of the ZNE community outside California – in places that have “real” weather – sometimes scoff at the lack of challenge of accomplishing ZNE here. Admittedly, our populous coastal areas benefit from benign climates, but we also have both very cold climates, such as Redding (similar in heating degree days to Chicago), and very hot ones, such as Palm Springs. Other factors also make this a challenging environment for housing innovation, among them high costs, a highly mobile workforce, and a notoriously litigious culture. Thus creating successful, marketable, ZNE projects is a non-trivial feat.

All the projects represented here have met the pinnacle of ZNE achievement: verified site ZNE. That is, not only was each project designed to be capable of achieving ZNE, but utility bills provide objective evidence of occupants’ energy use yielding ZNE in actual operation over the course of a full year. Further, site ZNE (explained in the introduction) is the most difficult definition to meet. These projects therefore demonstrate, importantly, that operational site ZNE (to which source ZNE is equal, for all-electric projects) is an achievable benchmark. These proofs of viability are absolutely critical to supporting the State’s likely push towards residential electrification in years to come. The project developers whose work is showcased here are thus to be both congratulated and thanked for their significant contributions to the future of housing in California, and beyond. Read on, and benefit from their experience.


Electrifying News!

lightning bolt | Dawid Cedler | Flickr

I’ve been talking to a lot of people lately about electrifying — that is, building an all-electric new home or eliminating natural gas and propane appliances in their existing homes. That’s something I plan to do myself any day now!
Meanwhile, for those building new or buying new appliances, I encourage choosing electric options. In case you’re not already of the same mind, here are my reasons:
1. I live in California, where we are rapidly moving towards cleaner and cleaner electricity production. Already 30% of our electricity is “clean,” i.e., produced by renewable energy sources such as wind turbines and photovoltaics, and Governor Brown recently signed legislation committing us to a 100% clean electric grid by 2045. Many other states will inevitably follow suit.
2. The International Panel on Climate Change has told us we have 12 years to throttle back fossil fuel emissions to prevent catastrophic climate change — but have you noticed that each time the IPCC reports, that time window gets smaller? I mean, smaller by more than the time elapsed since their preceding report! That means we probably REALLY have 5-10 years to cut emissions. Drastically.
3. Gas combustion in buildings is a very, very large fraction of our overall societal emissions. This is a part of the equation that as individuals we have the ability to change.
The single biggest objection raised to going all-electric is, “I can’t stand cooking on an electric range.” Here’s the good news: cooking on today’s magnetic induction ranges, although they do plug in, is otherwise a dramatic improvement over not only old-style electric cooking, but also over residential gas stoves. Everyone I know who has switched says they will never go back. I can’t wait to switch for the easier cleanup alone!!
Here are a couple of recent articles about induction cooking for your reading pleasure:

‘Zero Progress’ in California

Luminalt solar installation - Getty Images

Luminalt solar installation on San Francisco home (Getty Images)

Ha! Got you, didn’t I?!

The real story is about the progress we’re making toward zero carbon. A couple of recent milestones are adoption by the California Energy Commission (CEC) of the State’s building energy standards, Title 24-2019, effective January 1, 2020, and CA Senate passage of SB 1477 (Stern, Low-Emissions Buildings Market Development); the bill is now making its way through the State Assembly.

Title 24

While much has been published about the landmark solar mandate in Title 24-2019 — the first time a state has required installation of photovoltaics (PVs) on residential projects — mainstream media outlets have largely overlooked the significance of this code update as a step on the journey, set in motion in 2006, towards the State’s “big, bold” zero net energy (ZNE) goals. Requiring PVs doesn’t achieve ZNE, as the arrays are only required to offset ‘typical electric uses’ — i.e., excluding the typical (and not inconsequential) gas loads of space and water heating, cooking, and clothes drying. However, it’s a step in the right direction. Of particular note is that this version of Title 24, like all its predecessors, was required to meet stringent rules ensuring cost-effectiveness — that is, the standards must save consumers more than they cost. While many who work in this field (myself included) believe the cost-effectiveness test needs to be updated to encompass societal costs associated with fossil fuel combustion, the current rules do ensure that the solar mandate will not pose a financial hardship to new home buyers (notwithstanding propaganda to the contrary by nay-sayers).

In today’s San Diego Union-Tribune, CEC’s Commissioner Andrew McAllister provides a good overview of the requirements. “From day one, the savings from lower electricity bills more than offset any additional payment associated with financing through a mortgage. Costs will be even lower by 2020, especially in large developments where solar equipment will be procured and installed in bulk. The standards also allow larger, community-scale solar instead of individual rooftop systems — another potential cost-reducer. And exemptions to the solar requirement apply for shaded sites and infeasible roof configurations, and where local power is uncommonly inexpensive.” McAllister goes on to remark that the new standards also “encourage grid-friendly technologies such as battery storage, thermal storage and demand response to be installed alongside solar. The standards also make it easier to build an all-electric home — a clean, low-carbon trend that is expected to grow.” Furthermore, as an alternative to purchasing PVs outright, home buyers will have the option of leasing a PV system at very low or no up-front cost.

While it’s somewhat doubtful if California will ever truly mandate ZNE on individual residences — for perfectly good reasons, including the emergence of potentially more cost-effective alternatives such as the community solar approach that McAllister cites — the State is forging ahead on the path to zero carbon, which is, after all, the real goal; ZNE was simply conceived as a means to that end.

SB 1477

SB 1477 is described in a support letter submitted to Senator Stern on June 13 as providing, “technology-neutral incentives directly to builders and developers to design and build low-emissions buildings, and [spurring] innovation in the market for space and water heating equipment in California … This bill also targets incentives to Californians who need and deserve the most support. Higher incentives will go to low income housing and buildings in disadvantaged communities. In addition, space and water heating equipment that are most likely to improve the health, safety, and energy affordability of low-income households will be prioritized.”

The letter, signed by Design AVEnues and nearly 40 other organizations, was drafted by Natural Resources Defense Council (NRDC), which has been leading the lobbying efforts on this important climate change bill. NRDC’s Pierre Delforge reports, “Following amendments in the Senate, the bill now proposes that the market development programs be funded from an annual allocation of 5 percent of the cap and trade allowance revenues received by electric and gas utilities. SB 1477’s incentive programs are well aligned with the purpose of the cap and trade allowance revenue to fund GHG reduction programs, and using this funding source would avoid any impact on rates.” The bill will be heard by the Assembly Utilities Committee on June 27, and support letters are due by June 21. The draft bill can be reviewed and comments can be submitted on the State’s website (here).


Is there such a thing as TOO MUCH PV on your roof?

My view: NO.

The State of California, however, has another view, revealed through planned changes to our venerable energy code, Title 24 Part 6.

Around a decade ago the State set “big, bold” goals for all new homes to be ZNE by 2020 (also, for all new commercial buildings to be ZNE by 2030). However, in the intervening years since those goals were established, a few devils have been found amidst the details. One such Aha is that, while conceptually having a home produce enough energy to supply its own needs on an annual basis makes perfect sense, at high rates of adoption this presents some grid-level challenges. Specifically, most of the renewable energy production will come from rooftop photovoltaics on sunny afternoons … hmmm … but that’s not when most of the demand occurs! The demand peak occurs later in the day, when people come home and start to cook, tinker with their thermostats, etc. This imbalance is illustrated in the rapidly-becoming-famous “duck curve” graph.

So now there’s concern about “grid harmonization,” and the State is indicating that future versions of the energy code will limit “excess” PV and/or require that it be countered by onsite energy storage to address this imbalance. Even now, “excess” solar energy production is effectively discouraged by utility rate structures that ensure you will never see good value for PV capacity above and beyond your own annual electricity load — not even when it’s there to compensate for natural gas use, for example.

Paradoxically, the State has also acknowledged that as it moves to higher levels of clean energy (via increases in the renewable portfolio standard, or RPS), in the next couple of decades most of the new renewable energy supply will come from PVs. A bit of a disconnect?

Notably absent from presentations on State plans to address the “duck curve” are discussions of providing UTILITY-LEVEL energy storage. While eager to point out that PV is more economical at utility scale (true), they don’t seem to be nearly so quick to comment on whether it might be equally more economical to provide energy storage at utility scale (that seems likely to be true, no?!). This seems an obvious omission and should be added to the public discourse, promptly.

Also absent from the blithe comments about how, really, we should be looking to install utility-scale PV rather than putting it on all the little rooftops, is any observation about the massive ecological impacts associated with utility-scale solar developments.

My vision for a clean energy future includes a diversity of solutions, with solar on rooftops both small and large, wherever it is productive. Just as nature is not efficient, but rather smart, simple economics are not the final determinant of what makes sense. What makes sense is to preserve wilderness for all its uniquely important values, and limit the footprint of intrusive human developments such as solar farms to the greatest extent possible.

Reflections here provoked by some of the presentations at this week’s excellent Symposium on Zero Net Energy Buildings and Beyond, presented by the Emerging Technologies Coordinating Council. My thanks to all of the organizers and speakers for your contributions!

Webinar 9/26: To Zero and Beyond – North American Trends in Zero Energy and the Virtuous Cycle

Join me at 1pm PDT on September 26 for this global webinar event during the WGBC’s World Green Building Week, focused on the hottest growing trend in residential building: Zero Energy (ZE).

Register at

Get the latest insights on the exciting growth in ZE residential development in the US and Canada. The Net Zero Energy Coalition will present highlights from its recently published 2016 Residential ZE Report, along with findings on the drivers behind that growth and keys to ZE builders’ successes. We will also hear lessons learned from California’s pioneering efforts in ZE code and policy development, along with other insider perspectives on where zero energy is headed.


Gene Myers is owner and CEO of Thrive Home (formerly New Town Builders), Denver’s leader in building green, energy efficient production homes and recent winner of the U.S. Department of Energy’s Housing Innovation Award. THRIVE is Denver’s largest builder of for-sale affordable housing.

Mindy Craig, Principal and Owner of Blue Point Planning, was the lead author on California’s New Residential Zero Net Energy Action Plan for the CPUC and Existing Buildings Energy Efficiency Action Plan for the CEC. She is currently working on developing the New Commercial Buildings ZNE Action Plan and is leading the implementation of the ZNE Residential Plan.

And yours truly — Ann Edminster, M.Arch., principal of Design Avenues and NZEC Board director. Read more about me at

Register at After registering, you will receive a confirmation email containing information about joining the webinar.

Pruning the Gas Tree – A Great Idea!

A decade ago, zero net energy (ZNE) was barely on the radar of the building industry – even barely on the radar of many in the energy efficiency community. And electrification (read: getting rid of gas) was even less a topic of discussion. That has changed in a VERY big way in the last year or so. Increasingly, the ZNE community is of the mind that natural gas and propane don’t fit into our clean energy future; we have to eliminate their combustion footprint.

If anything, the State of California’s recent giant step backwards re new home energy performance – from ZNE by 2020 to zero net electricity by 2020 – has served to heat up this conversation. I’m not going into all the details of that now, suffice to say that ZNE requires offsetting all household energy – both gas and electricity – and thus sets a considerably higher bar than zero net electricity. Granted, there are legislative obstacles to ZNE by 2020, but nevertheless, this shift has been extremely disappointing to many of us in the ZNE community. Essentially, it sweeps gas under the rug for at least one more code cycle (3 years), along with all of its downsides.

As you’ll see if you follow the “downsides” link, Massachusetts-based Home Energy Efficiency Team ( is all over this, and they’ve come up with a genius idea for a pilot: Pruning the Gas “Tree.” The essence of it is a competition calling for residents on stub streets to agree to invest utility funds that otherwise would be spent on pipe upgrades, to electrify their homes and shut off the gas line to their street. They’ve figured out the costs, and it’s a total win-win. Let’s replicate this in every utility territory in the country!

International Finance Corporation and Architecture 2030 Collaborate on Zero Net Carbon Buildings for the developing world.

A fishing village just a few years ago, Shenzhen is now a megacity. Photo: YoTuT

Architecture 2030 once again demonstrates international leadership with this new partnership.

Architecture 2030 and the International Finance Corporation (IFC), a member of the World Bank Group, have partnered to support the international architecture and building community in designing zero net carbon (ZNC)buildings worldwide.

IFC created the EDGE program, a green building certification system with free online software for emerging markets. As part of the partnership, EDGE software has been enhanced to include carbon reporting, as well as recognition for the procurement of off-site renewable energy and carbon offsets.

Read more here.