Solar Ready - Code Compliance and Beyond

Since 2008, California has seen a substantial, steady increase in photovoltaic (PV) array installations. The trend has been spurred and supported by California’s statewide Zero Net Energy goals, including the California Energy Commission (CEC)’s “Solar Ready” requirement, which was added to Title 24 in 2013.

The 2016 code, which took effect in January of this year, had some minor updates, but the overall intent is the same:  design new roofs with conduit pathways and clear, available space for a solar system regardless of whether or not the building owner expects to purchase a system. The requirements apply to both residential and non-residential new construction projects.

The foresight has proven effective, especially as we see the price per installed watt of solar electric generation decrease. The average cost for residential PV in 2010 was $7/watt; five years later in 2015 it had dropped to just under $4/watt. Today you can find companies advertising residential installations for under $3/watt! This means owners of residential and commercial buildings constructed after 2013, who in the recent past might not invest in solar, are now doing so and have roof space available already, thanks to the solar-ready requirement.

Whether your project triggers “Solar Ready” by code or if you are just getting prepared, here’s a summary to give you a head start on what the 2016 Solar Ready requirements look like.

Solar Ready Non-Residential

Applicable to:

·      Hotel/Motel less than 10 stories

·      High-rise multifamily less than 10 stories

·      All other nonresidential buildings three stories or less

The Solar Zone, an unshaded, obstruction-free area can be located on:

·      Roof

·      Overhang

·      Roof of another structure (within 250 feet)

·      Overhang of another structure (within 250 feet)

·      Covered parking installed within the project

·      Trellises, arbors, patio covers, carports, gazebos…

Minimum Solar Zone (SZ) Area

·      No less than 15% of total roof area (subtract skylights)

·      Can be multiple subareas with no dimension less than 5 feet

·      If total area ≤ 10,000 SF each sub-area must be at least 80 SF

·      If total area > 10,000 SF each sub-area must be at least 160 SF

      Note: If the site has significant shading, exceptions are available.


·      If the roof pitch is greater than 2:12, then the roof must be oriented south or west (between 110 and 270 degrees of true north)

·      If the roof pitch is less than 2:12, orientation requirements do not apply


·      Obstructions (vents, chimneys, roof mounted equipment) must have a horizontal distance (D) of at least two times the height difference (H) between the highest point of the obstruction and nearest point of the solar zone, or D ≥ 2H (see diagram below)


·      Obstructions north of the solar zone are not subject to horizontal distance requirements

Interconnection Pathways

Construction Documents must indicate:

·      Location for inverter and metering equipment

·      Pathway for conduit from Solar Zone to the point of interconnection with the electrical service. No installation requirement, just drawings to show conduit location


·      A pathway for routing of plumbing from Solar Zone to Water Heating system, no requirement to installing piping

Fire Code Access Requirements

·      PV arrays shall not have either axis dimension exceed 150 feet

·      PV arrays shall provide a 6’ wide access perimeter around edges of roof

·      Smoke ventilation options must exist between array installations and next to skylights or smoke/heat vents

Solar Ready Residential

Applicable to:

·      Single Family Residences located in subdivisions with ten or more single family homes

The Solar Zone, an unshaded, obstruction-free area can be located on:

·      Roof

·      Overhang

Minimum Solar Zone (SZ) Area

·      The SZ’s total area will be no less than 250 SF

·      Can be multiple subareas with no dimension less than 5 feet

·      If total area ≤ 10,000 SF each sub-area must be at least 80 SF

·      If total area > 10,000 SF each sub-area must be at least 160 SF

Orientation, Shading, Interconnection and Fire Code: Similar to non-residential


The Solar Ready code provides an important baseline for any business or homeowner to install PVs after a project’s completion, an increasingly likely occurrence given the falling prices of solar panels. For those with bigger renewable energy goals, maximizing roof area while understanding the limitations of orientation, shading and fire access will help avoid frustration at installation time.

If you’d like assistance with solar ready compliance or calculations, let us know!


Streamlining LEED v4 Paperwork in California!

It’s been nearly a year since the U.S. Green Building Council (USGBC) announced the closing of registration for LEED v3 projects.  If you (or your team) have hesitated to jump into a new project for fear of the complicated documentation that often comes with new standards, fear no more.  At least if you are in California.

USGBC’s President and CEO Mahesh Ramanujam recently announced a noteworthy change in the certification process here in the Golden State.

Specifically, new commercial projects built to California’s robust building codes are pre-approved for significant streamlining of documentation. Qualifying projects will be able use code compliance documentation in order to satisfy all LEED v4 B+C prerequisites and earn 6 points in credits across the various categories.

USGBC hopes to simultaneously reward projects for meeting the stringent California statewide code standards and encourage more projects to pursue LEED certification (presumably, since everyone will already have a head start). A full list of streamlined measures can be found here.

Thinking about LEED for your next project?  Contact us!

Paris or Bust!

With the dramatic shift on climate policy announced recently by the federal government, many are wondering where we stand and where we are headed with greenhouse gas emissions (GHG). There is good news!

As an industry, the U.S. building sector is on track to not only meet, but exceed, the voluntary emissions reductions agreed to under the Paris climate accord.

Specifically, U.S. reductions were targeted at 21-28% below 2005 levels by 2025. According to the U.S. Energy Information Administration (EIA) 2017 projections, we are on track to reduce by 24.5% in that time frame, and 30.4% by 2030.


This is in stark contrast to the EIA projections in 2005 for building energy consumption and GHG emissions that had predicted an increase of 52.4% by 2030. 

Think about that – going from a projected increase of 50% to a decrease of 30%.

And according to the folks at Architecture 2030, who compiled much of the data for this post, consumption levels are dropping even though over 30 billion square feet have been added to our building stock. With an estimated $522 billion saved on energy costs so far, that’s money that can go back into funding green job creation, product development... and your summer vacation.

Keep up the great work everyone!

Induction Cooktops - Worth A Second Look?

Cooking over an open flame.  It’s primal, fast, and has become de rigueur for most new construction. But with growing interest in Zero Net Energy, is it time for gas cooktops to go the way of incandescent bulbs and gas-guzzling SUVs? 

Appreciated for offering quick heating and almost infinite, and instantaneous, temperature control, gas cooking has long been popular in both residential and commercial settings.  But with improved electric cooktops – namely induction models – the gap between electric and gas cooking is closing.

Glass-top electric stoves of the past used radiant heat passed through the glass to heat pots and pans.  This presented some predictable problems:  slow heating, hot cooktop surfaces, and lack of controllability.

The newest generation of electric stovetops, though, uses induction, or electromagnetic fields, to transfer energy.  This results in faster heating, greater control, and greater safety, as once the pot has been removed the energy transfer (aka heating) is interrupted.  Plus they look sleek, clean up easily, and don’t present the same indoor air quality issues that gas raises.  The improvements are sizeable enough that they have caught the attention of restaurateurs and Michelin chefs.

There are downsides, namely: cost – ranging from $1200 up to $5000; not all cookware will work on induction stoves; noticeable internal fan noise is not uncommon; and one still may need to choose between setting the heat at “3” or “4” when “3½” is what you really want. 

These are perhaps balanced out by the larger issue of climate action.  As prices for solar PV drop and California moves toward more production of electricity through renewable sources, all-electric homes become not only part of the solution for reducing carbon emissions, but also a way for developers to save on infrastructure costs by eliminating costly gas lines altogether. Unfortunately, old cooking patterns can be hard to break: we can efficiently design homes with electric space and water heating, but on a large housing project we recently worked on, the developer was reluctant to drop gas altogether due to market demand for a gas cooktop.

People, planet, and profit.  Perhaps induction cooking is worth a second look.

More pros and cons of induction cooking can be found here.


Century Center Towers Achieves LEED Certification

The City of San Jose has a new LEED certified building to celebrate.  The 422,863 SF mixed-use project offers two 12-story residential towers over commercial space, with a podium level pool and gym.

swenson-essex_304xx4026-2684-537-0 copy.jpg

The project benefits from savings on some key components:

Energy: Century Center Towers uses 34% less energy than a similar typical residential tower.  A cool roof and light colored pavers on the podium help reduce Heat Island effect (helpful around that pool!).  Additionally, all systems have been commissioned to ensure that they are working at optimal performance.

Water:  Through the use of water-efficient landscaping and xeriscaping, the project has reduced outdoor water use by a whopping 61%.  Indoor water savings are 22% over baseline.

Connectivity:  Century Center Tower’s location cuts down on carbon emissions from transportation.  Situated near bus lines, light rail, and the airport, it also provides ample bike storage for residents and visitors.  Eight EV-charging stations have been installed in the parking structure for those zero emissions-friendly commuters.

Materials: Over 30% of the materials used in the project are local/regional (produced within 500 miles).  Additionally, over 90% of construction waste was diverted from landfills.

Daylighting:  Just about every square foot of the spaces (91%) enjoys natural daylighting, providing a great environment for productivity and healthy living.

We’d like to congratulate all the members of the team on this well-deserved recognition:

Builder: Swenson

Architect: Swenson

Mechanical/Electrical/Plumbing: Emerald City Engineers

LEED Consultant: In Balance Green Consulting

Landscape: The Guzzardo Partnership

Civil: Kier & Wright

Hot Tips for Hospitality

As one of the greatest water-users, hospitality projects provide one of the greatest opportunities for water conservation. While an office building’s indoor water use is pretty small, once you fold showers and laundry into the water-use equation for a hotel, many possibilities open up. Here we focus on laundry solutions that can provide big operational savings and can make the difference in getting project approval in drought-conscious California.

How much water

Rule of thumb for laundry is 12 lbs of laundry per room per day, and 3 gallons of water per lb per load using conventional washing equipment. So, for a 100 room hotel, we’re talking 3,600 gallons per day, or 1.3 million gallons of water per year! Here are some great options that can be used individually or in combination.

Hilton Homewood Suites in Palo Alto appreciated the water savings from this ozone system, with the added bonus of longer linen life!


Laundry Options

·      Ozone – Injecting ozone gas into the wash water serves as a very effective cleaning agent with very little detergent needed and no bleach. Everything but restaurant linens can be washed in cold water, and without the chemicals, the rinse cycles are reduced, saving 30% on water overall. Check out WaterEnergy for more details.

·      High-efficiency washers – all kinds of equipment are designed to use less water. An intriguing one is the use of polymer beads such as Xeros. Small beads do the agitation work, reducing the water volume to about .6 gallons per load!

·      Laundry-to-landscape (L2L) – Depending on how much landscaping is in the project, laundry waste water can be used for irrigation. ReWater has a clever, low-cost system, and there are other products that have more sophisticated treatment and storage. We prefer ozone systems when using laundry-to-landscape to reduce chemical contamination.

·      Recycled Laundry Water – Recycling laundry water for re-use as laundry water has the best water savings. It does require some storage capacity and the current up-front costs warrant at least a 100-room hotel. Voltea and AquaCell have systems specific to commercial laundry.


Here is the comparison we developed for a 100-room hotel, assuming 80% occupancy and 12 lbs laundry per occupied room per day.

Next Steps

When comparing systems, several factors will weigh in – cost of water, cost of sewer, area of landscaping, space constraints for equipment, and, of course, up-front cost. Still, it’s likely at least one of these options will be a good match for your hotel, or even multi-family housing project.

And if you’re really looking to the future, check out this 1-minute video of a dryer that uses vibrations instead of heat to dry – all electric ZNE, here we come!


860 On the Wye Goes ZNE!

A new all-electric affordable housing project for veterans is set to open in San Luis Obispo next month.  The innovative Housing Authority of San Luis Obispo project will host residents in a 21-unit, two-story multi-family building with a common space, recreational facilities, a community garden, and onsite resident services from the U.S. Veterans’ Administration.

Early in the process, In Balance was contacted to consult on energy efficiency, inclusion of photo-voltaic panels (PV) in the design, and the possibility of making it a zero-net energy (ZNE) project.  There was no existing gas line to the property, an opportunity the owner seized upon to use savings from not extending services toward funding an all-electric development.

Jennifer Rennick, lead energy consultant on the project recalls, “A major challenge with all-electric multi-family housing is choosing a hot water system.  For 860 on the Wye, the team was able to identify a high-efficiency tank-style air source heat pump heater that could provide the volume needed without excessive energy loads.”  Additional efficiencies were gained through improved envelope construction, blown-in insulation, and integrating air-source heat pumps into the design to provide heating for the building. All available roof area now houses PV panels to achieve the ZNE goal.

In Balance also helped facilitate applications for incentives through the Multi-Family Solar Housing (MASH) and California Tax Credit Allocation Committee (CTCAC) programs, which helped the project meet basic cost requirements.

Congratulations to the whole team who made 860 On The Wye a success!