Title
2026 MAC ASHI Spring Technical Seminar

Summary
- Inspecting 10-amp Circuits and Conductor Requirement Upgrades by Mike Twitty
- Inspecting EV Charging Systems by Mike Twitty
- Understanding the House-as-a-System and Avoiding Unitended Consequences by Tessa Murry

Description

Date And Time
05/02/2026

Venue Name
Carnation Room

Venue Physical Address
1150 Carnation Drive Rockville Maryland Map

Details

Building Science for Home Inspectors: Understanding the House-as-a-System and Avoiding Unintended Consequences

This four-hour course explains the fundamentals of building science as they apply directly to residential home inspections. Participants will learn how heat, air, and moisture move through homes, how modern construction practices and energy-efficiency upgrades have changed building behavior, and why isolated improvements can create unintended consequences when systems interactions are overlooked. Emphasis is placed on recognizing patterns of risk related to health, safety, comfort, durability, and indoor air quality.

Through real-world inspection case studies, inspectors will learn how to identify system failures, assess risk thresholds, and communicate findings more effectively to clients. This course is designed for inspectors who want to elevate their inspections beyond checklists, strengthen client education, and protect themselves from future liability.

Upon completion of this course, students will be able to apply core building science principles to residential inspections in a practical, systematic way—allowing them to recognize risks earlier, anticipate unintended consequences, and provide clearer, more defensible recommendations to clients.

Inspecting 10-amp branch circuits and conductor requirement updates

The development of LED lighting in recent years has greatly reduced lighting loads in homes and business settings. The National Electric Code has responded to the lower power demands by making changes to minimum ampacities and conductor sizes for branch circuits that supply lighting.

Copper-clad aluminum (CCA) wiring is gaining popularity for branch circuit supplies in new construction. The NEC has made changes to address these installations as well. Photo examples of CCA NM cable and MC cable will be included.

In this course, we will cover all newer requirements and revisions associated with these products and circuits. Home inspectors must be trained to properly inspect and identify these installations. Manufacturers of conductors and overcurrent protection devices are currently in the early stages of production to comply with these changes.

We will also discuss the possible concerns and issues that may arise from improper installations of these lower ampacity circuits.

• Course introduction and scope
• Comparision of lighting loads with LED luminaires and incandescent and fluorescent fixtures
• History of NEC changes to accommodate 10-amps circuits and smaller conductor sizes
• Permissible loads on 10-amps circuits
• Copper-clad aluminum conductors; Cable types, Manufacturers, Ampacity ratings, permitted usage, and identification techniques
• Product development delays: AFCI protection
• Potential issues: Improper load connections, exceeding box fill, compatible terminal ratings

Inspecting EV charging systems

Advancement in technology always presents new challenges to home inspectors. Electric vehicles are becoming increasingly common. Understanding the power systems for EV charging in both commercial
and residential settings requires some additional training for electricians and home inspectors.

In this course, we will cover the different types of charging systems, along with branch circuit requirements. Over-current protection, GFCI requirements, maximum loads, and receptacle ratings will be explained.
The inspector’s responsibilities and limitations will also be discussed. This training is necessary to educate home inspectors about the load demands these systems require. EV charging circuits will often become
the largest source of power consumption in a home.

• Level 1, 2, and 3 charging supplies: Explain the different voltages, amperages, and options 
• Common terms and definitions
• In-depth look at level 2 charging systems: Receptacle types and ratings
• Adapters and different manufacturer's configurations
• GFCI requirements
• Continuous loads
• Inspector's responsibilities and limitations

Mike Twitty is retired from a 17-year home inspection and compliance inspection career. He is a licensed electrician, and is certified by the ICC and IAEI as a residential building inspector and residential electrical inspector. Prior to becoming a home inspector, he retired from a 30-year career with Ford Motor Company where he worked as an industrial electrician. Mike currently provides continuing education training for home inspectors across the country on electrical subjects and has authored many technical articles for national publications.

Tessa Murry is the founder of Your House Coach and an experienced building scientist, home consultant, and educator specializing in home performance. Tessa holds a Bachelor's degree in Residential Building Science and Technology from the University of Minnesota and has over 18 years of industry experience, including leadership roles in construction, energy auditing, home performance diagnostics, and home inspection. She spent seven years conducting over 2,500 residential inspections with Structure Tech Home Inspections, one of the nation's leading inspection companies. Today, Tessa consults with homeowners, contractors, and building professionals, helping them navigate repairs, upgrades, and home performance challenges with a holistic systems-based approach. She is passionate about teaching the principles of building science in a way that is clear, practical, and directly applicable to fieldwork. Tessa has taught at industry conferences and continues to develop continuing education courses focused on empowering industry professionals to better serve and protect their clients.

Sponsors

Brianne Smith of InspectorPro Insurance

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Dee Goldstein of Gem Marketing