Federal ADU Financing Programs: Fannie Mae & Freddie Mac Explained

One of the first questions homeowners ask when planning an accessory dwelling unit (ADU) is how to pay for it. While some homeowners use cash or home equity, others are surprised to learn that there are conventional mortgage options designed to support ADU projects.

Although there is no federal “ADU loan” program, government-sponsored enterprises (GSEs) like Fannie Mae and Freddie Mac have expanded their guidelines in recent years to better accommodate ADU projects. These organizations do not lend money directly to homeowners. Instead, they purchase mortgages from lenders, helping create standardized loan programs that can make financing an ADU more accessible.

While this article focuses on federally backed mortgage programs, there are many other ways to finance an ADU, including home equity loans, HELOCs, cash-out refinances, construction loans, and more. For a complete overview of all available options, read our ADU Financing Guide.

If you’re planning to build an ADU are interested in government backed financing options, here’s what you should know.

How Fannie Mae and Freddie Mac Support ADU Financing

Fannie Mae and Freddie Mac are federally chartered organizations that help keep the mortgage market functioning by purchasing qualifying home loans from banks and mortgage lenders. Because lenders know these loans can be sold to Fannie Mae or Freddie Mac, they are often more willing to offer financing that follows their guidelines.

For homeowners, this means there are conventional mortgage products that can be used to finance an ADU project, refinance an existing mortgage while funding construction, or in some cases use projected rental income to help qualify for financing.

While availability ultimately depends on the lender, these programs have made ADU financing significantly more mainstream than it was just a few years ago.

Fannie Mae Financing Options for ADUs

Fannie Mae supports several mortgage products that may be appropriate depending on your project.

HomeStyle® Renovation

The HomeStyle® Renovation loan allows qualified homeowners to purchase or refinance a home while financing eligible renovation projects, including constructing a new ADU on an existing property. This can be an attractive option for homeowners who already own their property and want to combine construction costs into their mortgage rather than obtaining a separate construction loan.

Potential benefits include:

• Financing construction through a conventional mortgage
• Combining renovation costs with a purchase or refinance
• One loan instead of multiple financing products
• Fixed-rate and adjustable-rate options may be available

For many homeowners building a detached ADU, this is the Fannie Mae program most applicable to their situation.

Construction-to-Permanent Financing

Homeowners building a brand new primary residence with an ADU may be eligible for a Construction-to-Permanent loan.

Rather than obtaining separate construction financing and then refinancing after completion, this option finances both the construction phase and the permanent mortgage through a single loan structure.

While not as applicable for homeowners adding an ADU to an existing property, it can be a useful option for those building an entirely new home with an ADU included in the original design.

HomeReady®

Fannie Mae’s HomeReady program is primarily designed for qualifying low to moderate income borrowers purchasing or refinancing a home with an existing ADU.

One advantage is that qualifying borrowers may be able to include rental income generated by the ADU when applying for the loan, helping improve purchasing power.

Since most SnapADU clients are building a new detached ADU rather than purchasing a property that already has one, this program is generally less applicable, but may still be worth discussing with a lender if it fits your situation.

Freddie Mac Financing Options for ADUs

Like Fannie Mae, Freddie Mac supports conventional mortgage products that can help homeowners finance ADU construction through participating lenders. While Freddie Mac does not lend directly to borrowers, its guidelines allow lenders to offer financing for eligible renovation and construction projects.

CHOICERenovation® Mortgages

One of Freddie Mac’s primary renovation financing products is CHOICERenovation®.

This program allows qualified borrowers to finance eligible home improvements, including constructing an ADU, as part of their mortgage rather than obtaining separate financing. Potential benefits include:

• Financing renovations through a conventional mortgage
• Combining the home’s value and renovation costs into a single loan
• Available with eligible fixed-rate and adjustable-rate mortgage products
• Compatible with several Freddie Mac mortgage programs, including Home Possible® and HomeOne®

For homeowners planning to add a detached ADU to an existing property, CHOICERenovation may be worth discussing with a lender familiar with ADU financing.

CHOICEReno eXPress®

For smaller renovation projects, Freddie Mac also offers CHOICEReno eXPress®, which provides a streamlined financing option for qualifying improvements.

While many detached ADU projects exceed the scope of smaller renovations, this program may be appropriate for homeowners completing less extensive work or combining multiple improvements into one financing package.

Eligible ADU Properties

Freddie Mac also has guidelines for properties with ADUs. In general, eligible properties may include:

• Attached or detached ADUs
• Garage conversion ADUs
• ADUs above detached garages or other accessory structures
• Basement ADUs

To qualify, the ADU generally must:

• Have its own kitchen, bathroom, and separate entrance
• Be independent from the primary residence
• Be smaller than the primary dwelling
• Meet applicable zoning and lending requirements

These are general requirements for a permitted ADU – learn more about ADU Basics. Freddie Mac also provides appraisal guidance for lenders, encouraging appraisers to use comparable homes with ADUs whenever possible when determining market value.

These Are Not Direct Government Loans or Grants

It’s important to understand what these programs are and are not. Fannie Mae and Freddie Mac do not provide loans directly to homeowners. Instead, they establish guidelines that participating lenders follow when originating conventional mortgages.

Likewise, there is currently no nationwide federal grant program that pays homeowners to build an ADU. While some state and local governments occasionally offer incentives or financing assistance, these programs vary by location and funding availability.

For most homeowners, financing an ADU still involves working directly with a bank, credit union, or mortgage lender.

Choosing the Right ADU Financing Option

Every homeowner’s financial situation is unique, and the best financing option depends on factors like your available equity, existing mortgage, credit profile, construction budget, and long-term goals. While federally backed mortgage programs offered through Fannie Mae and Freddie Mac can be an excellent fit for some homeowners, they’re just one of several ways to finance an ADU.

Our comprehensive ADU Financing Guide compares other common options, including HELOCs, home equity loans, cash-out refinances, construction loans, and paying cash, so you can better understand which approach may be right for your project. If you’re unsure where to start, SnapADU can also connect you with a reputable lender to discuss the financing options available for your specific situation.

Frequently Asked Questions