In June 2015, the California Energy Commission (CEC) voted unanimously to approve updated building energy efficiency standards that would cut regulated energy use in new homes by 28% and save consumers $31 a month compared to houses built under the previous energy code. The new standards also were to set the stage for zero-net-energy new homes in the state by 2020.
Known as "Title 24," the standards went into effect on January 1, 2017, and set minimum energy-saving requirements according to the Natural Resource Defense Council (NRDC) for new buildings and renovations to reduce energy used for lighting, heating, cooling, ventilation and water heating.
Once rooftop solar electricity generation is factored in, homes built under the 2019 standards will use about 53% less energy than those under the 2016 standards, the CEC reports. This will reduce greenhouse gas emissions by 700,000 metric tons over three years, equivalent to taking 115,000 fossil fuel cars off the road.
When the full standard goes into effect on January 1, 2020, its first job is to ensure that as little energy and water are needed as possible. Homes built after that date are expected to have very energy-efficient attics and walls, improved windows and doors, and properly installed insulation or other efficiency upgrades that provide equivalent savings.
According to Code Watcher, under this code, new buildings will be efficient enough that their electricity use can be offset by a modest number of solar panels. Consequently, for the first time, building energy standards will take on another role: in 2020, they will require that rooftop solar panels be installed on new single family homes and low-rise multifamily buildings to offset the home’s expected annual electricity use and achieve zero-net-electricity status.
The standards are expected to provide an incentive for solar energy storage systems, with a focus on in-home battery installations but also including thermal storage such as flexible electric water heating and air conditioning, that run when demand is low and when there is abundant solar energy on the grid. It is also expected that these systems will reduce energy use during peak demand and homeowners will receive an expanded credit toward the home energy efficiency score.
These changes promise to reshape the construction industry in significant ways and not just in California. Carl S. Sterner, LEED AP, the director of design and sustainability at Sol Design + Consulting, believes it will drive the adoption of building energy codes by other states, speed the development of building monitoring and management technologies, accelerate on-site energy storage and reduce the cost of high-performance building.
The home building industry doesn’t have to wait 15 months to see how to design and develop using these code changes; the BUILDER KB Home ProjeKt concept home will provide a living demonstration of “Where Tomorrow Lives.”
A high-performance envelope is critical in achieving a net-zero home and it all starts with good design and planning before the foundation is poured or a nail is hammered. KTGY Architecture + Planning and KB Home have partnered on many energy-efficient residential communities over the last decade as well as the first KB ProjeKt concept home for the Greenbuild Expo. Working in partnership and incorporating net-zero elements early in the process will save time and money while maintaining a high level of design.
With the KB Home ProjeKt manufactured by robots in Entekra’s plant, the quality of the wall construction exceeds that of site-built walls. What may be the most visionary element of the envelope is the utilization of Kingspan Kooltherm K12 Framing Board. This premium-performance insulation product has a fiber-free rigid thermoset phenolic-insulation-core faced on both sides with a low-emissivity composite foil facing. It is resistant to the passage of water vapor, unaffected by air infiltration, and can be used between studs or as an insulating sheathing. When you add the R-value of 16 to the rest of the wall assembly, the KB Home ProjeKt walls will have twice the energy efficiency of today’s homes.
All of the Whirlpool appliances in the home are state-of-the-art when it comes to the energy required to operate but it is the Carrier Comfort heating and air conditioner product that probably has the biggest impact on reducing energy demand. The variable refrigerant flow (VRF) system is the industry’s first single-phase VRF outdoor unit with heat recovery. The system provides zoned comfort with the capability to heat and cool up to nine individual zones simultaneously. All of this with a seasonal energy efficiency ratio (SEER) rating of up to 22.7, far exceeding the SEER of 14 required in California’s new code.
Although the products in the KB Home ProjeKt will be “smart,” it’s the Wiser Energy Smart Loadcenter that ties them all together. Its key features include real-time alerts when devices turn on or off and automated fault detection as it monitors critical energy loads, solar panels and battery storage. The Wiser Energy Smart Loadcenter’s integration with Google Home provides homeowners with real-time visibility to electric costs, energy saving recommendations and increase appliance uptime with reduce service costs.
While the California Energy Commission voted unanimously in 2015 to approve updated building energy efficiency standards to cut regulated energy use in new homes and require net-zero-energy home by 2020 in California, the ripple effect certainly will spread across the rest of the country. Perhaps the biggest ripple will be the KB Home ProjeKt providing the home building industry with 2020 vision.
See the home in Vegas in 2019. Register now www.builderonline.com/kbhomeprojekt.
