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Use Energy Modeling and Building Envelope to Build Net Zero Energy Homes

California hosts more than half of all the net-zero buildings in the United States., a survey on Net-Zero Energy Coalition suggests. The survey is the first effort to catalog all of the zero-energy buildings in North America.

California stated last year that it wishes to make a self-sustaining marketplace letting all new homes to be net zero by 2020. The government has been chipping away at market barriers for zero-energy buildings for nearly a decade.

Net zero buildings are the ultimate statement of Green construction. All major players, be it Telsa’s Gigafactory or bride of Gulf in Basra, Iraq all are aiming for Net zero structures. So what is it that Net Zero buildings require? Well it just has to produce the energy as much as it consumes. However easy or no-big deal it looks; it is currently posing a major challenge to construction fraternity. So from where do you begin?

You need to begin with designing smartly

Designers, architects and contractors have to be on same page since the seeds are sown. They should know the measures of a Net-zero energy building and what it takes to build it. The things to be considered first and foremost is an ideal site selection that has an unobstructed sunlight, that which is least affected by external conditions. Once you are done with this, hire a solar contractor who can assess the site according to requirements. You need to clearly state the thermal boundary on design plans.

Use Energy modeling

Energy modeling will spill the beans immediately that which of energy saving features is most cost effective. Energy modeling tools like Equest & Energy plus helps builders find the least expensive measures needed to build a zero energy home. Modeling is expected to be conducted in various repetitions of the design, evaluating the energy influence of diverse design picks, such as a ground source heat pump versus an air source heat pump, or comparing the impact of R-30 wall insulation with that of R-60 wall insulation. Energy modeling enables to deduce the stage at which returns in efficiency are no more cost effective but are a blend of energy saving measures to give utmost savings. However it’s not possible to derive an exact net cost of difference as they vary time and again as per building construction markets. Though energy modeling can only provide estimates, it still is a best guide to refer to for utilizing energy saving measures and achieving cost efficiency.

Pushing building envelope

Air sealing a home is largely reflected as the best cost-effective way to lessen heating and cooling energy usage. It also improves on two important grounds- comfort and indoor air quality. In case you have failed to notice, high-performance houses have an incessant air barrier. The secret to this continuity is to find the large sheets of materials that is already out there and bridge the gap to seal the structural sheathing.

Insulating, along with sealing, all six sides of the net zero building envelope optimization are fundamental steps in the construction of zero energy homes. It is essential to insulate the walls, floors and ceilings with types and thicknesses of insulating materials that fit the specific needs of each surface, and to design wall, floor and ceiling assemblies to accommodate those materials.

After this, builders should think through mechanical, electrical and plumbing (MEP) systems for energy competent customs of heating and cooling the building, including choices like geothermal heat pumps that use comparatively steady temperature subversive, via a piping system, to cool, heat and provide hot water.

So what’s more to come for net-zero?

"It’s an exciting time right now," Smedley, director of sustainability at Skanska USA. said, "because of what I would call a groundswell to actually build these types of projects. Whether it’s on the innovation side or the testing side or actual payback side, (net-zero buildings) are starting to make sense, so I think it’s exciting that we’re finally getting there."

She added, "I think we’re at the tipping point, and it’s going to be exciting to see what the next handful of years brings."

Conclusion: I couldn’t agree less. With 62% of Americans believing in increasing global warming as a threat, it is obvious that energy saving is their priority when it comes to building house or upgrading the building system. And if you are one of those, I am assuming you are up for energy audit and taking a new path to net zero energy home for time ahead with some major remodeling goals this year. Energy modeling and Building envelope are the initial steps towards building Net zero energy home. Needless to say, the most important one that helps in achieving energy efficiency. 

Content Discussion

Meg Matt's picture
Meg Matt

Thank you for your post on ZNE.  While there are issues to work out to make ZNE a mainstream part of the energy efficiency landscape, the key to success will be leadership from architects, builders and contractors working in concert with utilities and regulators. The New Buildings Institute is working to help lay the groundwork, and Opinion Dynamics is involved in researching and evaluating ZNE. 

I look forward to reading additional posts.