PLEASE NOTE: This post has been updated as of February 2015. For the most current information, visit the new post - Difference Between BPI and RESNET
Are you interested in becoming an Energy Auditor? Have you looked at the various standards, options and utility programs in your area? The broad swath of incentive programs are a great way to help you start or expand your energy auditing or retrofitting business. Well, if you've looked into any of these programs, you've probably concluded that you need to become a HERS Rater or a BPI Building Analyst. In fact, almost all of city, state and utility incentive programs require an individual to have one of these professional certifications to qualify.
So what is the difference between BPI and RESNET? How do their testing standards differ? If you haven't already seen our What is BPI and What is RESNET explanations, I recommend reading them before continuing. For this post, I will focus specifically on the training differences between their professional credentials:
Similarities: BPI and RESNET both teach the exact same principles of building science, energy loss and heat flow in a home. Both review standard practices for energy auditors and home performance contractors. Both test candidates on the blower door - a pressurization testing tool. And, lastly, both pre-approve and qualify third party training organizations to administer their training and examinations.
Differences: RESNET, however, requires 40 hours of training and includes duct testing and energy modeling, while BPI does not have a length of training requirement and includes combustion safety testing. RESNET does not have Combustion Safety Testing and BPI Building Analyst does not have duct testing. Additionally, BPI has multiple levels and specialties of certification, whereas, RESNET has the HERS rater only.
Written Exam Comparison: BPI's exam is 100 multiple choice questions with 70 percent required to pass, while RESNET's exam is only 50 multiple choice questions with a minimum score of 80 percent required to pass. BPI's written exam is longer but generally considered easier to pass. RESNET's exam is open book and open Internet, while BPI's exam only allows you to have a copy of their standards. You'd think that an open book exam would be easier, but it's not. RESNET's higher passing score requirement and toughly worded questions really make that exam much harder than BPI. With the exception of a handful of curveballs, the BPI exam is a fairly straightforward test. Overall, both exams rigorously test your knowledge of building science and your basic carpenter's math skills (Can you find the area of a wall? How about the volume of a house?).
Field Training Comparison: For the field training, both use the blower door as a primary training tool. BPI focuses on the energy audit process, the blower door and combustion safety testing. RESNET focuses on duct testing using a duct blaster. It makes sense if you know that BPI is based out of New York (a heating climate, more likely to have a combustion appliance) and RESNET is based out of San Diego (more likely to have a forced air duct system for air conditioning). BPI requires you to pass one proctored field audit to complete your training. For BPI, you can actually fail your field exam if you do not follow the testing procedures exactly. RESNET, however, does not have a field exam per se, however, you must complete five proctored audits after passing the written exam to become a fully certified HERS rater.
So which should certification you pursue – RESNET HERS or BPI Building Analyst? Both, if you can afford it, but otherwise, the general rule of thumb is that RESNET focuses on new and newer homes, while BPI focuses on older and existing homes. Right now there is not much in the way of new residential construction, so BPI is the most popular standard and is likely going to be the credential required for contractors to participate the upcoming “Cash for Caulkers” program the federal government will be unveiling soon. Once you’ve chosen a certification make sure you chose a licensed BPI training affiliate or RESNET training provider. That will ensure you have no problems qualifying for the exams and field training.