Highlights from the Zero Net Energy Series

Our four-part series on ZNE strategies, presented with Allen Construction and the Central Coast Green Building Council, opened last month to a sold out crowd.

For those unable to attend, here’s a glimpse at some of the highlights:

ZNE Compliance – Jennifer Rennick:

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A common definition for ZNE is that a building produces as much energy as it consumes.  While that is the case for “operational ZNE”, California’s Title 24 code will require projects to comply via one of two methods.  The performance method will be based on the Energy Design Rating (EDR), while a prescriptive method will use conditioned floor area (CFA) and a Dwelling Adjustment Factor to determine compliance.

What a difference sealing an attic can make – Scott Nyborg:

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Using measured data from a renovation project in Los Angeles, the effects of air sealing and insulation on attic temperature were shown to be dramatic.  While indoor temperature initially fluctuated in sync with outdoor air temperature (OAT), as measures were put in place the variability was reduced from 20 degrees to 5 degrees in a 24-hour period.

For more information, see the Central Coast Green Building Council's website.



Strategies for Collecting and Using Rainwater - Residential Edition

In a winter season that seems set to bring more sunshine than rain, it is easy for rainwater collection to drop to the bottom of anyone’s priority list.  Yet, long periods of warm dry weather punctuated with short intense storms make smart water use - especially if you have irrigation needs - all the more important. 

Depending on how, and how much, irrigation water you use, several capture options can make sense.

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Small (50gal) free standing rainwater tanks: Typically connected via a diverter from a residential downspout, these tanks or “rain barrels” are inexpensive and easy to move from one collection location to another.  They can fill up quickly (roughly 0.1 inches falling on a 1000sf roof) and are handy to use for watering nearby plants, pots, or a tree.

Large (5000gal+) tanks:  More expensive and requiring much more room in a yard (about 8 ½ ft diameter), they also need to be plumbed, filtered and maintained.   That said, they can be connected to each other and to pumps, which for large properties may offer more bang for the buck especially through dry summers.

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Portable water pillows/bladders: A relative newcomer to the market, these flexible flat “balloons” made of material similar to that used in rubber rafts come in a variety of sizes and shapes.  Several manufacturers now make them with price tags that can vary widely. 

The innovation here is that they lie flat, so they are well-suited for crawl spaces or under decks, thereby freeing up yard space.  DIY hookups and pumps make the water available for landscape use.  They can also be drained and rolled up for storage in the dry season.

For winters that bring rain via frequent small storms, the smaller tanks or barrels can work well to water during the gaps and then let them refill with the next rain.  For years like this one (and likely future ones?), with infrequent larger storms, storage systems with large capacities become more important (and useful) to make it through even the “wet” season.  Be sure to check with your local jurisdiction regarding permitting requirements.

As water rates continue to move toward reflecting the real cost of provided water, the benefits (for plants and for your wallet) of capturing rainfall become more evident.  The important thing is to get started!


Onsite Water Reuse Takes a Another Step Forward

Ever wondered what tertiary treatment really means?  Interested in graywater for toilets but don’t know where to start?  Looking for ways to move your project closer to net-zero water (and energy for that matter)?

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The long-awaited “Onsite Non-Potable Water Reuse Practice Guide” was recently released by the William J. Worthen Foundation.  Following years of research on and advocacy for bringing water reuse strategies to the public, the practice guide offers readers specifics on how and why reuse may be right for your next project.

With chapters on “The Right Water for the Right Job” and “Can I Get this Thing Permitted?” as well as detailed information on how to build a system that works for you, the 87-page guide comes complete with references, additional resources and case studies. 

It's a great read for practitioners and the general public alike.  The downloadable .pdf is available on the Foundation’s website.

And Now for Some Good News on GHG Reductions

We often talk about the "energy-water nexus", recognizing that pumping, cleaning and treating water is a significant contributor to energy use. In 2015, water conservation programs in California reduced water use by more than 20%, but the energy savings and subsequent GHG reductions weren't quantified, until now.

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In a new study of the California drought, researchers show that "the decrease in water usage translated into a significant electricity saving of 1,830 gigawatt hours (GWh). Interestingly, those savings were around 11 percent greater than those achieved by investor-owned electricity utilities' efficiency programs over the same period."

The study goes on to note that the water-saving strategies are similar in cost to programs that directly target energy reductions, so we will likely see more integrated energy/water conservation programs in the future. And that's good news!

Modeling Suntubes to Design for Daylight

The benefits of natural light within the built environment have now been researched, written about and accepted as a fundamental design characteristic in successful architecture. Creating a connection to the outdoors provides the stimulation required to regulate our circadian rhythms, which can result in improved comfort and productivity. In addition, increasing natural daylight in our homes and work environments decreases the demand for electric lighting and therefore, electricity consumption.

While traditional skylights can provide a good visual connection to the outdoors, suntubes are better insulated, are more efficient at distributing daylight without glare, and don’t have the ‘thermal liability’ of a skylight. Suntubes, Solatubes, SunTunnels, Solar Tubes - whatever brand or label you choose - all are products we often recommend in our projects that have proven to be a real asset to daylighting design. Although they are often located in a project using ballpark guidelines, computer daylight modeling provides more opportunity for strategic placement.  Below are two of our recent projects with examples of how the products were used, lessons learned, and best practices.


Lompoc Transit Center

The Transit Center was built with four large commercial bays that included fleet maintenance spaces, a bus wash station, office space, support and storage space. The client’s experience at other facilities was that the bay doors were being left open to bring daylight into the spaces which caused issues with wind, dust and glare. Rather than closing the doors and installing high bay electric lighting, we were brought onto the team to investigate suntubes as an alternative solution. We ran daylight simulations comparing light levels for different times of the year, with the bay doors open and closed, with different quantities of tubes, and an option of Kalwall systems in certain buildings.

A sample comparison below shows daylight levels on a summer day with eight tubes (left) versus sixteen tubes (right):

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The suntubes were very effective in bringing highbay light into a space without using any electricity.

One complication for this project was when we began designing the roof top solar arrays. CalFire requires a 4-foot clearance around all openings, including suntubes, and at the eaves. In our effort to properly daylight the spaces that could not be effectively reached using side lighting, we were also carving out roof top area that would be unavailable for solar modules.

A solution that emerged was moving some of the planned solar PV panels to the canopy over an adjacent work area.  This allowed some of the electricity generation to be assumed by a concentrated installation, while freeing up space on the main building for daylighting mixed with a smaller PV footprint.


Financial Building

This project comprised a three-story multi-use building with significant glazing on all orientations, using a spandrel glazing system. We assisted the design team in improving the building’s daylight by making suggestions such as glazing performance specifications, altering the footprint shape and rearranging interior spaces to increase the depth of daylighting.

Through modeling, we demonstrated that a thinner footprint provided greater opportunity for daylight and had improved energy performance. The architects - Arris Studio Architects - were then able to create a building with great perimeter daylighting. We then focused on improving interior spaces such as common work areas of the third floor. We recommended a “shared light” strategy where suntubes were placed throughout the corridor, and the interior office doors were changed from solid to glazed, creating more consistent light levels on the top floor from the perimeter to the core.

Initially the owner group also wanted a large skylight in the lobby area but after modeling different scenarios, we suggested multiple suntubes that would still provide ample daylight but reduce glare, prevent UV-light from fading the furniture, and reduce heat gain that would have occurred with a single large skylight. You can see in the image below that four suntubes were located in the interior rectangular space directly in front of double doors to bring in light for occupants deep in the space, while single suntubes provide daylight to both the corridor and the adjacent interior spaces (through glazed doors).


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Suntubes, interior glazing, a thinner footprint, and coordination with roof-mounted solar panels are all strategies to achieve a high performance building that is a great place to work. To achieve all that, daylight modeling is a great tool for effective design decisions.

Zero Net Energy Series Kicks Off in 2018

Considering a Zero Net Energy (ZNE) project?  Wondering how to get started?  Looking for specific technologies to address your design challenges?

Beginning in January 2018, Zero Net Energy will be the focus of a series of four educational presentations offered the second Tuesday of the month (January through April).  Tackling topics ranging from the newest technologies to tried-and-true practical approaches, the series aims to help designers, contractors and owners understand the foundations of what makes a ZNE building work.

The series is open to the public, registration required.  Cost: $15/$40/$60 (students/members/non-members) for entire series.  To sign up or get more information, see the CCGBC's event website.


Congratulations to CCGBC 2017 Green Award Winners!

The Central Coast Green Building Council's biannual Green Awards were held recently at The Sandbox co-working space in Santa Barbara, CA. 

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This year's awards were organized in six categories: New Construction, Landscaping, Innovation, Operations, Renovation and Homes. 

In Balance Green Consulting had the pleasure to work on several projects that received recognition.  The 860 on the Wye multi-family veteran's housing project and INhouse: Solar Cal Poly were both honored as Green Homes; the new Caltrans offices in San Luis Obispo were recognized as a  Green Renovation; and MindBody's new corporate headquarters received the top award in New Construction.

Congratulations to all the winners and their project teams!


What's New in 2018: Commercial Clean Energy on the Central Coast

The Central Coast Green Building Council will be hosting an interactive workshop Thursday, November 30, 1-2pm, on upcoming financial incentives for commercial projects considering solar installations.

Attendees will learn about financial products available to commercial property owners as well as hear an update on Community Choice Energy and the Santa Barbara County Commercial PACE (property assessed clean energy) program.

Registration is required.  To learn more, see CCGBC's website for the event.