Santa Clarita homeowners usually pay for an ADU with a HELOC, a home equity loan, a cash-out refinance, or a construction or renovation loan. The right choice depends on your equity, your current mortgage rate, and how the project’s costs arrive. Get contractor bids first, because lenders want real numbers.
ADUs in the Santa Clarita Valley commonly cost about $50,000 for a simple Junior ADU up to $350,000 or more for a large detached unit. See ADU costs in Santa Clarita. Here’s how the main financing options compare.
How do the main ADU financing options compare?
| Option | How it works | Best for |
|---|---|---|
| HELOC | A credit line against your equity; draw as needed | Strong equity and flexible timing |
| Home equity loan | A lump sum, usually at a fixed rate | Firm bids and a predictable payment |
| Cash-out refinance | Replaces your mortgage with a larger one | Owners whose current rate is near today’s rates |
| Construction or renovation loan | Funds released in draws, sometimes based on after-project value | Larger projects or limited current equity |
| FHA 203(k) | FHA mortgage that includes renovation costs | Conversions and attached ADUs with lower equity |
Is a HELOC a good way to pay for an ADU?
Often. ADU costs come in phases, from design to permits to construction, and a HELOC lets you draw only what you need and pay interest only on what you’ve drawn.
- Pros: flexible draws, and you keep your existing first mortgage.
- Cons: rates are usually variable, and your home is the collateral.
When does a home equity loan make more sense?
When you have firm bids and want a fixed payment. You get the full amount at once and start paying interest on all of it right away.
Should you do a cash-out refinance?
Only after running the numbers. A cash-out refinance replaces your whole mortgage. If you have a low rate from earlier years, giving it up can cost far more over time than a HELOC or home equity loan on just the ADU amount.
How do construction and renovation loans work?
These loans release money in draws as work is completed, with inspections along the way. Some lend against the home’s expected value after the ADU is built, which helps when current equity is limited. Fannie Mae’s HomeStyle Renovation loan and FHA’s 203(k) are two common types. Expect more paperwork and a slower closing than a HELOC.
An FHA 203(k) can fund converting part of a home into an ADU or adding an attached ADU, but HUD’s guidance doesn’t clearly cover a new detached ADU. See FHA 203(k) loans for ADUs.
Can ADU rent help you qualify for a loan?
Sometimes. FHA rules from 2023 let lenders count ADU rent toward qualifying income, generally at 75% of the lesser of the appraiser’s market rent or the lease, and capped at 30% of total qualifying income. Some conventional loan programs also allow ADU rental income in limited cases. Ask each lender how they treat it.
Before you borrow, check whether the rent covers the new cost. In August 2026, Santa Clarita 1-bedroom rentals averaged about $2,190 a month. A $200,000 ADU financed at 7.5% over 30 years costs about $1,400 a month in principal and interest, before roughly $200 to $300 for added property tax and insurance. See renting out your ADU for the full example.
Are there ADU grants?
Not reliably. California’s CalHFA ADU grant offered up to $40,000 for pre-development costs, but CalHFA says its latest round was fully allocated in December 2023, and no new round has been announced. See California ADU grants.
What should you have ready before talking to a lender?
- Contractor bids or a detailed estimate
- Your home’s estimated value and mortgage balance
- The ADU type and size, and plans if you have them
- A realistic timeline
- Soft costs such as design, engineering, and permit fees, which commonly run tens of thousands of dollars before construction starts
What financing mistakes should you avoid?
- Borrowing before you have bids. A loan based on a guess can leave a project half-funded.
- Forgetting soft costs. Design, engineering, permits, and utility fees all need funding.
- Ignoring your current rate. Refinancing a low-rate mortgage can be the most expensive option.
- No contingency. Keep 10% to 15% available for surprises.
Ready to get real numbers?
Call (661) 486-8393. If no one answers, leave a voicemail with your name, phone number, address, and the type of ADU you want. You can also use the contact form. We’ll pass your details to a local ADU contractor who can price your project, so you can take real numbers to a lender. There’s no obligation to hire. We don’t offer loans or financial advice; compare several lenders before you borrow.
ADU financing FAQs
What is the most common way to finance an ADU?
Home equity, through a HELOC or a home equity loan, is a common route for homeowners with enough equity.
Can I get a loan for an ADU without much equity?
Possibly. Construction and renovation loans, including FHA 203(k) and Fannie Mae HomeStyle, can lend based on the home’s value after the project. Requirements vary by lender.
Does ADU rental income count toward a mortgage?
It can. FHA allows it with limits, and some conventional programs do too. Ask each lender.
Is a cash-out refinance a good idea for an ADU?
Only if your current rate is close to today’s rates. Otherwise a HELOC or home equity loan usually costs less.
Are ADU grants available in Santa Clarita?
Not reliably. CalHFA says its latest ADU grant round was fully allocated in December 2023. Plan the project without grant money.
Related ADU guides
- FHA 203(k) loans for ADUs
- California ADU grants (2026 status)
- Is building two ADUs worth it?
- How much does an ADU cost in Santa Clarita?