Energy Auditing Explained
About BPI and RESNET

New to Energy Auditing?
Seeking an Industry Certification?
Interested in a BPI Certification?
Want to Become Eligible to Offer Incentives and Rebates?
Already Know What You Want? Register for a BPI Training Course:
- BPI Building Analyst
- BPI Envelope Shell
- BPI Building Analyst/Envelope Shell Combo Course
- BPI Multifamily
- BPI Heating Specialist Analyst
- BPI Air Conditioning / Heat Pump Cooling Specialist
- BPI Weatherization Installer
- NREL BPI Energy Auditor
- NREL BPI Retrofit Installer
- NREL BPI Crew Leader
- NREL BPI Quality Control Inspector
What is Residential Energy Auditing?
A residential energy audit is an inspection and analysis of a home's energy flows for the purpose of improving energy conservation. A certified energy auditor will use diagnostic equipment to evaulate the energy efficiency of a home, and to suggest the most cost-effective ways to improve efficiency and raise the level of comfort for occupants. There are different levels of energy audits, but the most comprehensive and effect ones are performed by Home Performance Contractors, Building Analysts, Energy Inspectors or Home Energy Raters.
In an effort to reduce overall energy consumption, this service is often facilitated by utilities, energy services companies, independent insulation contractors, or the federal, state, or local government.
A comprehensive energy audit generally includes blower-door tests (done both before and after upgrades), combustion appliance inspection and repair, air quality testing including carbon monoxide detection, duct testing and airflow testing.
While an energy auditor may advertise and perform only energy auditor services, most professionals gravitate towards offering contracting or remodeling services as well. Additionally, many contracting businesses will market themselves as Home Performance Contractors rather than Energy Auditors since auditing may be just one of the services they offer, and many Home Performance Contractors prefer to make the improvements suggested by the audit themselves. This requires additional training, as the competencies to perform an audit are not necessarily the same as those required to execute an effective energy efficiency retrofit.
In addition, there are standardized rating systems that provides a score that indicates a relative energy use of the home compared to others of the same size in that region. The most prevalent of these is the HERS (Home Energy Rating System) Index, which puts buildings on a 0-100 scale. Home energy ratings generally apply to new home construction or major remodeling.
DIAGNOSTIC EQUIPMENT

Blower Door - A blower door is a powerful fan that mounts into the frame of an exterior door. The fan pulls air out of the house, lowering the air pressure inside. The higher outside air pressure then flows in through all unsealed cracks and openings. A blower door tests how air-tight a home is. Air leakage reduces comfort by allowing moisture and cold drafts to penetrate your home, and can be responsible for as much as 40% of heating and cooling costs.

Duct Blaster - A duct blaster combines a small fan and a pressure gauge to pressurize a house's duct system and accurately measure air leakage of the ductwork. This test is similar to a pressure test is similar to a pressure test of a plumbing system. Duct leakage can increase heating and cooling costs over 30% and contribute to comfort, health and safety problems.

Infrared Scanning - Infrared thermography is equipment or method, which detects infrared energy emitted from object, converts it to temperature, and displays image of temperature distribution. This identifies invisible trouble spots in a home’s insulation, allowing for targeted repairs with maximum benefit and immediate savings.

Pressure Pan - This tool identifies a home's worst energy leaks be they ducts, outlets, openings, etc in order to allow for prioritization of work.

Combustion Analyzer - This device is used to ensure that mechanical equipment is burning efficiently and that environmental regulations are being met. It also identifies gas leaks in or out of the home.
Those interested in becoming a certified energy auditor should register for CleanEdison's BPI Building Analyst and Envelope Professional Training which covers how to use these various tools and conduct comprehensive energy audits for homeowners.
WHY GET AN ENERGY AUDITING CERTIFICATION?
The energy auditing business can get tricky at times. There are many factors that affect the performance of any given home, including the HVAC, lighting, air infiltration, appliances and even occupant behavior. In order to perform analyses of homes' energy performance, a contractor is expected to have their skills and knowledge verified by an independent third party. In addition, almost every local, state and utility incentive programs require an individual to have a professional certifications to qualify to participate in the program. There are a range of professional certification organizations, but by far the two most prevalent are the RESNET and BPI.
WHAT IS THE DIFFERENCE BETWEEN RESNET AND BPI?
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 approve and qualify third party training organizations to administer their training and examinations.
DIFFERENCES
Procedures - RESNET HERS Ratings include duct testing and energy modeling, while BPI includes combustion safety testing.
Certifications - BPI has multiple levels and specialties of certification, while RESNET only has the HERS rater.

Exam - 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 the 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.
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. 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 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.
WHICH IS EACH CERTIFICATION MOST APPLICABLE TOWARDS?
The general rule of thumb is that RESNET focuses on new and newer homes, while BPI focuses on older and existing homes.
WHERE CAN I START?
CleanEdison is a registered BPI Training Affiliate and RESNET Training Provider. Our courses are designed to both teach you the skills necessary to perform quality energy audits and the knowledge and tools needed to pass whichever certification you choose (some people have both). A great place to start is either a BPI Building Analyst Certification or a RESNET HERS Rater.
WHAT IS A BPI CERTIFICATION?
BPI Certifications are administered by the Building Performance Institute, Inc. (BPI). BPI is a recognized leader in standards development as well as a credentialing organization for residential energy efficiency. BPI works with building performance industry stakeholders to ensure that the professional bar for excellence in building performance contracting is established and maintained by creating and regularly updating technical requirements through an open, transparent, consensus-based development process. A contractor can earn their BPI Certification through a rigorous written and field examination process administered to individuals by BPI or its training affiliates.
WHAT IS INVOLVED IN THE BPI CERTIFICATION EXAMS?
The two-hour, 100-question, written exam requires a passing score of at least 70% while the two-hour field exam requires demonstrated competency with the energy audit process and equipment. BPI does not mandate formal training prior to the exams, but a classroom or online course is highly recommended. CleanEdison's BPI training courses involve 3-5 days of full-time training, which helps participants understand the relationship between all the systems in the house and its effect on occupant health, safety and comfort, and energy efficiency and durability.
WHY GET A BPI CERTIFICATION?
A BPI Certification indicates a high level of knowledge, skills and professional competency in the building performance industry. BPI measures the knowledge, skills and competency of individuals, and evaluates the organizations impacting building performance. BPI also offers added support services that promote and stimulate infrastructural development, emphasizing education and outreach.
Perhaps most importantly, a BPI Certification improves your business' competitive positioning and profitability. As a BPI Certified Professional, you will be able to provide customers with an economic forecast of return on investment through energy savings and ensure that the interaction of specific building systems does not create any harmful conditions. As energy costs continue to rise, this certification can bring you new business for years to come. By using building science technology to help customers solve heating, cooling and air leakage problems, you’ll also provide them with a more comfortable, safe and durable home.
ARE THERE ANY PREREQUISITES
Anyone can become BPI Certified. While no formal experience is necessary to participate in most examinations, we strongly recommend you enroll in BPI training course to gain some experience in the building energy performance industry.
WHERE DO I START?
There are a variety of BPI Certifications, but the first step is to earn your BPI Building Analyst and Envelope Professional Certifications. CleanEdison's instructors have over 20 years of experience in the industry and have trained thousands of individuals to pass the certification exams.
WHAT IS BPI ACCREDITATION?
Accreditation is a credentialing process for businesses, administered by BPI, that evaluates certain business practices, technical operations and quality management systems necessary to ensure the delivery of building performance services in conformance to BPI Standards. In addition, all BPI Accredited companies participate in BPI’s Quality Assurance Program and receive feedback on their home performance work.
WHAT ARE THE BENEFITS OF BPI ACCREDITATION?
More and more federal, state and local energy efficiency and weatherization programs require work to be completed by contractors from BPI Accredited businesses. Moreover, BPI Accredited companies enjoy a competitive advantage because they can prove their services and systems have been evaluated by an independent third party. The test-in/test-out protocols ensure installed improvements attain the desired goals, and that means fewer call-backs and happier, more satisfied customers. By increasing the scope of work, accredited contracting companies see an improved bottom line and earn a reputation for quality work.
Companies meeting and maintaining conformance with the requirements of these policies and procedures and the BPI Accreditation Agreement shall be designated as a BPI Accredited Home Performance Contractor. Contractors new to BPI Accreditation are afforded a 24 month period of skills development in their accreditation to meet all accreditation requirements.
HOW DOES A BUSINESS BECOME BPI ACCREDITED?
BPI requires BPI Accredited companies to employ a minimum of one full-time Building Analyst and one full-time specialty designation, such as Envelope Professional. These designations can be held by the same individual or by different employees.
Here is a list of the BPI Specialty Certifications that are eligible for Accreditation Application
- BPI Envelope Shell
- BPI Heating Specialist
- BPI Air Conditioning / Heat Pump Cooling Specialist
- BPI Whole House Air Sealing and Weatherization Installer
- NREL BPI Energy Auditor
- NREL BPI Retrofit Installer
- NREL BPI Crew Leader
- NREL BPI Quality Control Inspector
Here is the full BPI Policies and Procedures Manual
WHAT IS RESNET?
The Residential Energy Services Network (RESNET): RESNET is a national organization that regulates energy efficiency in buildings.
WHAT IS THE HERS INDEX?
A RESNET rating provides a relative energy use index called the HERS Index. HERS stands for Home Energy Rating System. A rating of 100 on the HERS Index represents the energy use of a standard building, while a rating of 0 indicates a new building that uses no net purchased energy.
WHAT IS A HERS RATER?
A certified RESNET energy auditor is called a HERS Rater. To become a HERS Rater, one must take a two-hour, 50-question written exam and pass with a score of 80% or better. One must also complete five provisional ratings within one year of passing the exam. Two of the ratings must be supervised by a RESNET training provider. The last three ratings are “probationary.” All ratings performed by a HERS Rater are submitted to a RESNET affiliate for quality control and approval.
HOW DO I BECOME A HERS RATER?
The RESNET Certification exam is a very difficult exam that even experienced energy auditors have trouble with. It is highly recommended that you prepare with a RESNET HERS Rater training course. CleanEdison's HERS Rater Training is four, 8-hour days with an instructor who has completed hundreds of ratings.
HOW DO I MAINTAIN MY HERS RATER CREDENTIAL?
To maintain the certification, one must take 12 hours of approved continuing education courses throughout the year.
WHAT KIND OF WORK IS AVAILABLE FOR HERS RATERS?
A HERS Rater is trained to do both home energy ratings and home energy audits. Home energy ratings generally apply to new home construction or major remodeling. This rating is necessary to qualify a home for the Energy Star Homes Designation. Home energy audits involve a prioritized list of improvements and a projected cost/benefit for each of the improvements. A HERS Rater directs customers to a qualified contractor to implement the improvements suggested in the audit.

