Where the most energy is used in your home and how to save
Learn where the most energy is used in your home and discover the biggest opportunities to save, plus tips on efficiency upgrades, insulation, air sealing, and rebates.
November 06, 2026
If you're considering a Mass Save® Home Energy Assessment or weatherization upgrades, it's helpful to understand the different program partners involved and the role each one plays.
Understanding the roles of Lead Vendors, Home Performance Contractors, and Independent Installation Contractors, can help you navigate the process with confidence and determine which option is the best fit for you and your goals.
In this guide, we'll break down what each partner does, what to expect throughout the assessment and installation process, and how recommended weatherization upgrades move from evaluation to completion.
If you qualify for the Mass Save Income Eligible Program, your pathway may differ from the options outlined below. Eligible households should visit the program page to learn more and get started.
The Sponsors of Mass Save offers two pathways for receiving a no-cost Home Energy Assessment and completing recommended weatherization upgrades, such as insulation and air sealing.
It's important to know that technical standards and pricing for air sealing and insulation upgrades is standardized through the program. That means there is no need to collect multiple quotes for weatherization work, allowing you to focus on selecting the pathway that best fits your preference and needs. The two options provided by the Sponsors of Mass Save are:
For some customers, the fastest path to recommended weatherization upgrades may be to work directly with a participating Independent Installation Contractor (IIC). These contractors specialize in insulation and air sealing improvements.
Once insulation and air sealing work is complete, the Sponsors of Mass Save offer no-cost Quality Assurance Inspections to help ensure the installed measures meet program standards and perform as intended. These inspections are available regardless of which participation path you choose or which participating contractor completed the work, providing an additional layer of oversight and confidence for homeowners.
Quality Assurance Inspections help verify that weatherization improvements are completed according to program requirements, giving customers added confidence in the long-term performance of their energy-saving upgrades.
With several program partners involved, it can be helpful to understand who is responsible for each step of the process. Here's a quick overview of the roles and responsibilities of Lead Vendors, HPCs, and IICs.
| Vendor Type | Role | Responsibilities |
|---|---|---|
| Lead Vendors | To support customers through the initial assessment and quality assurance process. | Conduct no-cost Home Energy Assessments. Provide recommendations and information on available incentives. Assign a participating IIC for weatherization work or help customers connect with an IIC of their choice. Conduct Quality Assurance Inspections. |
| Home Performance Contractors (HPCs) | To provide both Home Energy Assessment and installation services for weatherization projects. | Conduct no-cost Home Energy Assessments. Provide recommendations and information on available incentives. Complete air sealing and insulation upgrades if the customer chooses to move forward with the work May recommend additional improvements outside the Mass Save program. |
| Independent Installation Contractors (IICs) | Focus specifically on weatherization measures. | Specialize in insulation and air sealing installations. Help eligible customers move directly into weatherization work. Complete recommended weatherization upgrades. |
Understanding these distinct roles can help you choose the pathway that best aligns with your preferences while knowing exactly who you'll be working with at each stage of the process.
Whether you prefer to start with a Home Energy Assessment, are ready to move forward with insulation and air sealing improvements, or simply want to better understand your options, the Sponsors of Mass Save offer multiple pathways to help you get started. The right choice depends on your home's needs, your goals, and preferences.
If you have questions or would like assistance, the Mass Save Solutions Center is available to help.
A Solutions Specialist can help you understand your options, connect with the appropriate program resources, and take the next step toward a more comfortable and energy-efficient home.