What is the HERS rating process?

What is your score goal?

Perhaps your goal is being stipulated by requirements from the building department or neighborhood covenants, or a desire to qualify for Federal tax credits. Maybe the house is participating in an above-code program like ENERGY STAR, LEED for Homes or Passive House. Or maybe you just want the benefits and bragging rights that come with a net-zero energy house? In any case, the stated goal tells us much about how aggressive the energy consumption reduction measures will be.

At what point does the process start?

The sooner, the better. There are many ways to reach your HERS goal, but some are much more expensive than others. Early in a project it is easier for your HERS Rater to help you select the most cost-effective methods to achieve the goal. Questions that often come up at this stage; condition or vent the roof and crawlspaces, how good do the windows need to be, is the house letting too much sun in or not enough, what should the insulation strategy be, radiant verses force-air distribution systems, etc. If the process is started late, and your HERS Rater has little affect on the detailing of the house, and the house falls short of the goal, then there are few options. Sometimes an Owner can pay a fee-in-lieu of meeting the HERS goal. If not, then installing renewable energy, i.e. solar, may be the only viable course of action.

What does the process look like?

In a nutshell it goes like this… We do take-offs from the construction drawings and put them in an energy modeling software. We can start off with some assumptions and defaults, but eventual we have to know everything about the shell and mechanical system. We can work from DWGs (2010). PDFs are helpful too, and SketchUp models are great. Then the computer gives us a score. We can adjust the model at that point to get a better score. This is a valuable time to use the energy model to optimize the performance of the house and value engineer the energy features of house. When it gets to a point that works for everybody, then we print the projected HERS certificate for the permit application. During construction we will need to update the model with any real world changes and inspect the insulation before it is covered. At final, we inspect the mechanical system to insure it matches what we modeled and perform any required tests; typically just a blower door test to determine the air exchange rate. Then we send my file to our Quality Assurance provider, EnergyLogic, they check it out. If Okay-ed, they issue the final HERS certificate and upload the results to the RESNET national database.

Which party is typically responsible for shepherding the HERS Rating?

The HERS Rating process can be initiated by the Owner, Builder or Architect. In the end, it is a collaboration between all parties involved.

How do I find and engage a HERS Rater?

Search no further- Confluence Architecture has HERS Raters on staff. As architects, we understand those houses that are out of the standard mold.  Have a 20,000 square foot house?  Have a complicated remodel?  Have unusual construction assemblies?  We are the HERS raters for you.  HERS ratings fees vary with the size and complexity of home and typically range from $1000-$2000.  Call us for an estimate.