Seeking Energy Efficiency? Here’s why ZERH is an acronym you need to know.

9 October 2018

In the market to build or buy a brand new home? If energy efficiency is a goal, consider working with your builder or realtor to choose a Zero Energy Ready Home (ZERH).

The ZERH rating is given only to homes built to perform at the highest levels of energy efficiency. Requirements for ZERH are far more stringent than what’s required for EnergySTAR designation and, as a result, ZERH homes are typically 40 to 50 percent more efficient than a standard new home. [1] It’s estimated that a ZERH home can net a homeowner as much as $100,000 in energy savings over the course of a 30-year mortgage. [2]

What is ZERH?

The ZERH program, overseen by the Department of Energy, outlines a specific set of building guidelines which result in homes that are not only highly energy efficient but also quiet and resistant to leaks, mold, and outdoor air pollution/infiltration. ZERH homes, in short, are built to ensure residents’ long-term health and comfort.

Homes that earn the ZERH distinction – as you might guess from the name – are so energy efficient that their annual energy demand can be met entirely (or almost entirely) by renewable energy sources, such as solar panels on or around the building. Therefore, the home draws zero energy from a traditional energy grid.

Most ZERH homes are built with solar panels already incorporated into their construction. But for homeowners who wish to integrate renewable energy systems later, ZERH homes are built in such a way that the cost of later installation is minimized – hence the ready aspect of the Zero Energy Ready Home moniker. [3]

Currently there are about 2,000 ZERH-certified homes in the U.S., but that number is expected to grow exponentially in the coming years, with roughly 10,000 new and under-construction homes in the pipeline for certification. [2]

Cost Savings with Zero Energy Ready Homes

While it’s true that ZERH homes may be initially more costly to build than a standard home, they end up saving homeowners money in the long run, thanks to lower energy costs and even reduced long-term repair and maintenance costs.

The Zero Energy Project reports that while zero energy homes can cost roughly 5-10 percent more to build, they will ultimately cost less to operate and own in the long term than a standard-construction home. [4]

That’s why it’s important to factor in energy-savings when comparing the list of cost-to-build prices of a ZERH home versus a standard home.

The difference to build a ZERH home versus a standard home can be less than $10/square foot, and yet can reap an energy savings of $125-$200/month or more, according to online building plan provider 24hplans.com. [5]

The DOE estimates that in some cases, the energy savings from a ZERH home is so significant that it’s able to entirely offset the higher price of its monthly mortgage (when compared to a less efficient home). [3]

Further, one DOE study found that, because of its efficiency, the utility savings of the ZERH home was able to not only offset the initial higher cost of installing high-efficiency gas or electric HVAC systems – but in fact actually netted a positive return on those systems each month. (When compared to a home built to baseline 2012 International Energy Conservation Code (IECC) guidelines in Climate Zone 3, the ZERH home saw a net positive cash flow for cost vs. savings of its HVAC systems of $12-$14/month.) [6]

ZERH Requirements

In general, ZERH homes meet or exceed ENERGY STAR certification requirements for envelope sealing, duct sealing, insulation, water efficiency, HVAC quality and installation, and appliance and systems efficiency. The latest, full outline of ZERH home requirements (Rev. 6.0, enacted April 2017) is available here.

In fact, ENERGY STAR guidelines serves as a mandatory first-step baseline for a ZERH home. And then, to qualify for the ZERH certification, a home must also:

-Have high-performance windows that meet ENERGY STAR 5.0 or 6.0 guidelines

-Meet either 2012 or 2015 IECC codes for insulation levels (depending on state)

-Place ductwork only in conditioned spaces

-Include systems to conserve water and heat it efficiently

-Maintain indoor air quality as outlined in the EPA’s Indoor airPlus Program

-Follow the EPA’s PV-Ready checklist to reduce the cost of future solar panel installations

Builders can pursue either a “prescriptive path” or a “performance path” to achieve ZERH certification.

Additional Innovations

Beyond the mandatory guidelines to achieve ZERH certification, DOE encourages ZERH-home builders to go even further in pursuing high performance, including:

-taking additional steps to meet PHIUS+ guidelines and achieve Passive House status;

-reduce water use by participating in EPA WaterSense program;

-build using techniques and materials that increase the home’s ability to withstand disasters. [1]

The Bottom Line

The key takeaway here is simple: a ZERH-certified home represents one of the most high-performance, energy efficient houses available on the market today.

Thanks to their stringent building guidelines – which emphasize sealing the home’s envelope, insulating adequately, and prioritizing energy efficiency in all systems – ZERH homes provide owners a chance to enjoy not only lower utility bills, but also a house that’s built to last and provide years of worry-free comfort.

Find more information about the ZERH program, including ZERH-designated builders in your area here.

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