A Manufactured Home that could be “Net Zero” Energy Use within one year of operation

LEED is short for Leadership in Energy and Environmental Design.
Photo credit Modular Lifestyles.

The challenge to build proven “Net Zero” homes for the growing demand of home buyer prospects is ever growing for the home builders. The introduction of LEED, BuildItGreen and HERS raters creates the template but the actual guarantee sits with the contractor or factory home builder, not the architect.

In jurisdictions such as California, the Site Built and Factory Built new home industries will be mandated soon to comply with net zero standards. Many home builders have not built “Net Zero.” So their subcontractors are not use to having to be committed to build super energy efficiency, tight building envelopes or having their work reviewed by an independent HERS rater during their building task process.

The energy efficiency reports created by the energy efficiency experts lay the groundwork for the home to be built and copied. However, the tests offered for validation of performance are performed after the home is built. So the contractors task to prove the home after it has been built is difficult.

Home Energy Rating System (HERS).
It’s like golf — the lower the score, the better.
Credit: Green Building Advisor.

As this HERS thermometer shows the goal to (0) for a contractor to prove the reports and the final build to be tested at (0) is a challenge and be guaranteed.

Modular Lifestyles, Inc. has attempted (home photo shown above) is our customer’s choice of a 1352 sq ft manufactured home in Ojai, CA. We believe it to be practically “Net Zero.” The climate is rated a 9 out of 16 from the California Energy Commission climate zone report. The homeowner works for the local utility company and expressed her desire to be (0).

The home has 3.0 kWH solar pv system along with Energy Star rated appliances, “Energy Star” Tier I certified, and has all electric appliances except for the tankless water heater. We have not (yet) figured out how to eliminate water usage to “Net Zero.”

This home was chosen by the Ojai Valley Green Coalition to be a participant in October 2014 for their fundraising green home tour.

The homeowners first electric bill (June-July 2014) was $-45.00 on a “NEM Contract” with the utility company. The NEM billing cycle is annual accumulation using the monthly credits or debits, totaling them at the end of the year then the homeowner may have a balance due or credit on the final 12 month contract.

We believe this home will have enough electrical credits from one utility to pay the gas bill of the other utility to cover the expense of the operation of the natural gas Tankless Water Heater.

This EPA graph earlier above depicts the usage a home builder must review before building a “Net Zero” home. Many consequences of the homeowner usage patterns may greatly affect the final outcome of the home even though the builder took all aspects of living in his newly built home. Imagine the efforts he must take to guarantee “ZERO” usage and the electrical generation needed to offset the ‘Zero” usage. A builder must consider many scenarios when the sales contract is signed and his guarantee is now in force.

Time will tell our story in 2015 with the homeowners utility bills results to be shared. ##

By Steve Lefler, Modular Lifestyles, Inc.