The Quick Read: It depends on where the new loan balance lands against your county’s conforming limit. Conforming is the better fit when the payoff plus ADU money stays under that limit and you can work within a renovation product’s structure. Jumbo fits when the total crosses the limit, or when you want the funds as cash rather than held back for construction. Both replace your current first mortgage, and both are subject to lender guidelines and full file review.
That is the short version. The longer version is mostly about mechanics: how the limit gets tested, what a conforming loan will and won’t let you do with the cash, and what a jumbo lender decides for itself.
Jumbo cash-out estimate
Enter the value, the balance, and the cash wanted; choose the occupancy and the structure; the lanes, the payment, and the reserves follow.
Editable benchmark: 7.18% as of November 5, 2026 · Freddie Mac 30-year average via FRED®. A conventional market reference, not a jumbo cash-out refinance quote.
Illustrative starting assumptions: a $2,000,000 home value in the jumbo range, a $1,000,000 current balance, a principal residence on a thirty-year fixed structure at the current Freddie Mac conforming benchmark, and property taxes and insurance estimated at typical national rates. Every field is editable.
Illustrative estimate only — not a Loan Estimate, approval, quote, or commitment to lend. The rate field carries the weekly Freddie Mac thirty-year conforming benchmark, a market reference and not a jumbo cash-out refinance quote; a jumbo loan is priced by the lender at lock. The lanes shown are the wholesale cash-out lanes behind this page as of the snapshot date; the calculator reads each lane’s leverage, loan maximum by occupancy, cash-in-hand cap, and reserves as the lane table states them, and a Lendmire loan officer confirms the lane on the file. The cash available is the loan the lane allows less the balances paid off, before closing costs, which are not included; on most lanes a jumbo cash-out begins one dollar above the conforming limit for the county, and two lanes start at a stated dollar floor instead. The HELOC line is the line program’s combined loan-to-value ceiling applied to the same value and balance. Taxes and insurance are editable estimates. Licensed in sixteen states for consumer mortgages.
How the County Limit Decides Which Lane You’re In
The new loan amount, not your current balance, is what gets tested against the limit. That includes the payoff of your existing mortgage, any cash you take, and any costs rolled in. FHFA sets a baseline conforming limit and a higher ceiling for high-cost counties, calculated from local median home values. The number is county-specific and resets every year, so look up your county’s current figure instead of relying on a national number.
A loan one dollar above that county limit is a jumbo. That is the whole definition.
Here is where ADU files get tripped up. A homeowner with a conforming balance today adds the ADU budget, and the combined total crosses the line. The existing loan being conforming doesn’t matter. The new loan is what counts. Run the test early, before the builder’s bid is final, because a few percent of cash can be the difference between lanes.
Three common positions:
- Just under the limit: conforming works, but any cost overrun or rolled-in fee can tip you over.
- Just over: a choice. Take less cash to stay conforming, or accept jumbo and keep the full budget.
- Far over: jumbo is the only single-loan path.
Side-by-Side
| Factor | Conforming cash-out | Jumbo cash-out |
|---|---|---|
| Loan size | At or under county limit | Above county limit |
| Who sets the rules | Fannie Mae / Freddie Mac guides | Each lender or investor |
| Maximum leverage | Set by agency cash-out rules | Set by lane; cash-out sits lower than purchase |
| Credit floor | Set by agency guidelines | 660 decision score on the headline lane |
| Mortgage insurance | Required above agency LTV thresholds | Varies by lane and leverage |
| Occupancy | Primary residence for ADU rental income credit | Primary, second home and investment, at lane-specific leverage |
| Documentation | Plans, as-completed appraisal, contract on renovation product | Lender-specific; reserves scale with amount |
| Cash handling | Renovation funds typically held and drawn | May be taken as cash, depending on lender |
| Loan ceiling | County limit | Up to $5,000,000 on the largest lanes |
Treat the table as direction, not a promise. Leverage on jumbo is a ceiling: the headline lane sets the highest loan-to-value available, while several lanes stop a little lower on a combined basis and the rest stop at 80%.
What a Conforming Cash-Out Can and Can’t Do for an ADU
A plain conforming cash-out refinance is governed by Fannie Mae’s Selling Guide. It is separate from a limited cash-out refinance, which allows only small incidental cash back (the greater of 1% of the new loan or $2,000), and cash-out pricing applies only to the plain version.
That distinction matters for ADU work. The product built for adding an ADU on the conforming side is the HomeStyle Renovation mortgage. Fannie Mae states that Selling Guide products can be used to add an ADU to an existing home. But HomeStyle’s refinance purpose is limited cash-out. The renovation funds are held and released as work progresses. You don’t walk away with free cash.
Mechanics that show up in files:
- An as-completed appraisal is part of the file, and leverage on a limited cash-out is based on that as-completed value.
- Documents include plans and specifications, the renovation contract, and a certificate of completion.
- Work has to finish within the completion window set by Fannie Mae’s HomeStyle FAQ, and timing varies by file and lender.
- Not every lender offers HomeStyle. It requires special approval to sell to Fannie Mae.
Fannie Mae also defines the ADU. Only one is allowed on the parcel, it must be subordinate in size to the main home, and an independent second kitchen alone doesn’t make an ADU. The appraiser also reviews zoning compliance. An unpermitted structure is where conforming files stall.
One more point on income. Fannie Mae has expanded when ADU rent can help you qualify, but the conditions are narrow: a one-unit principal residence, one ADU, a cap on its share of qualifying income, and only on purchase and limited cash-out transactions. Confirm the current terms in the Selling Guide before counting on them. Projected rent from an ADU that doesn’t exist yet is not something to assume.
When Conforming Is the Better Fit
Conforming is the better fit when these line up:
1. The total stays under the county limit. Payoff, ADU budget and rolled-in costs all fit with room for overruns.
2. You’re comfortable with held-back funds. Construction draws against progress suit a single-contractor build with a clear scope.
3. The ADU is clearly legal. Permits, zoning and the one-ADU rule are settled.
4. Your income needs the help. If ADU rent could support qualifying, the conforming path has a documented rule, with caps.
5. Your lender offers the renovation product. That one is a gate. Ask first.
The trade-off is flexibility. You get the agency’s written rules, which means predictability, and you accept its structure.
When Jumbo Is the Better Fit
Jumbo is the better fit when the math or the structure doesn’t work in conforming. Across the wholesale programs Lendmire places files with, the common triggers are a combined balance above the county limit, a build budget that makes taking less cash unrealistic, or a borrower who wants funds as cash instead of a holdback.
Jumbo guidelines are set by each lender, not by a public rulebook. That cuts both ways. There is more room to fit an unusual file, and less published certainty about how an ADU gets treated. As the CFPB notes, jumbo rules vary by lender and usually call for good credit and a high down payment.
Within Lendmire’s jumbo cash-out refinance program, the lanes work like this in plain terms:
- Fixed, adjustable and interest-only structures are available.
- The headline lane starts at a 660 decision score, with loans up to $5,000,000 on the largest lanes.
- The ratio ceiling is 50% on the fixed lanes, 45% on the adjustable and 43% on the interest-only lanes.
- Reserves are counted in months of the full payment and rise with the loan amount.
- Above a lane’s threshold amount, two appraisals are required.
- Cash-out runs at lower leverage than purchase, and the largest lanes carry a cash cap.
All of it is subject to lender guidelines and full file review. Nothing here is a commitment to lend.
Questions to put to a jumbo lender early, because the answers aren’t standardized:
- Does the appraisal value the home as it is today, or with the ADU finished?
- Is there a holdback, or do funds arrive as cash?
- Will any ADU rental income count?
- How are overruns handled?
Underwriting still has to satisfy ability-to-repay rules. The CFPB’s compliance guide describes the price-based General QM framework in place since its October 1, 2022 compliance date. Don’t treat an older 43% debt-to-income figure as a federal cap.
The Catch on Staying Under the Limit
Taking less cash to stay conforming sounds tidy. Sometimes it is. But it can leave the ADU underfunded, and an underfunded build is a worse outcome than a bigger loan.
Think it through this way. Suppose the combined balance sits a few percent over the limit. You could trim scope, bring savings to the table, or accept jumbo. Trimming scope saves you from the jumbo but may change the ADU you actually need. Bringing savings keeps the loan conforming but drains liquidity you may want for overruns. Jumbo keeps the full budget but moves you onto lender-set guidelines and reserve requirements. Terms depend on the lender’s guidelines, the property type, the leverage, and a full review of the credit profile.
There’s no universal winner. Strong reserves and a simple build make staying conforming easier to justify. A firm scope and a budget with a cushion built in make jumbo easier to justify. Run both before deciding.
What Both Options Have in Common
Neither is a free lunch. A cash-out refinance replaces your existing first mortgage. If your current loan is favorable, you give it up. That is the main trade-off, and it applies equally here.
Per the CFPB’s home equity guide, the larger loan may lengthen your payoff time and may raise your monthly payment. Costs commonly include origination, appraisal and title fees. A cash-out is also different from a home equity loan or HELOC, which sits on top of your first mortgage instead of replacing it. Some owners pair a conforming first mortgage with a separate line for ADU draws. That is a legitimate alternative, and it is worth comparing against one larger jumbo loan.
Both are consumer loans, so you’ll receive a Loan Estimate and a Closing Disclosure.
Key Terms Defined
Conforming loan: A loan at or under the county limit set by FHFA, eligible for purchase by Fannie Mae or Freddie Mac.
Jumbo loan: A loan above the county conforming limit, with guidelines set by the lender or investor.
Cash-out refinance: A new, larger mortgage that pays off the old one and gives you the difference.
Limited cash-out refinance: A refinance that pays off the old loan and costs, with only small incidental cash back.
Accessory dwelling unit (ADU): A smaller, subordinate living unit on the same parcel as the main home.
As-completed appraisal: A valuation of the home as it will be worth once the planned work is finished.
A Pre-Application Checklist
1. Look up your county’s current conforming limit.
2. Add your payoff, planned cash and rolled-in costs, and compare the total to the limit.
3. Confirm the ADU is permitted and fits zoning, and that it meets the one-ADU, subordinate-size definition.
4. Get a written contractor bid and a scope with a cost cushion.
5. Ask each lender how the ADU is valued, whether funds are held back, and whether rent counts.
6. Document reserves, since jumbo requirements scale with the amount.
7. Compare the refinance against keeping your current loan and adding a separate line.
Frequently Asked Questions
Can a cash-out refinance pay for an ADU?
Yes, though the structure depends on the lane. A conforming loan generally routes ADU money through a renovation product with held-back funds. A jumbo cash-out may allow funds as cash, depending on the lender. Either way, the ADU’s legality and the appraisal approach drive the file.
What happens if my balance plus ADU funds crosses the county limit?
The new loan becomes a jumbo, even if your current loan is conforming. The limit applies to the new loan amount. You can reduce the cash, add savings, or move to a jumbo lane.
Does ADU rent count toward qualifying?
On the conforming side, there is a narrow rule for one-unit principal residences, one ADU and a cap on its share of income. On jumbo, treatment is set by each lender and isn’t standardized. Projected rent from an unbuilt ADU should not be assumed.
Is jumbo underwriting stricter?
Often it asks for stronger credit, more reserves and more equity, and it is set lender by lender. On the headline jumbo lane the decision score starts at 660, with reserves rising as the loan grows. All terms are subject to lender guidelines and full file review.
Should I keep my current mortgage and use a HELOC instead?
It’s worth comparing. A cash-out replaces your first mortgage, so a favorable existing loan is lost. A separate line leaves it in place but works differently. Which is better depends on your current loan and the budget.
The Balanced Verdict
Conforming suits the homeowner whose total stays under the county limit, whose ADU is clearly legal, and who accepts a renovation structure. Jumbo suits the homeowner whose total crosses the limit or who wants cash-flexible funding, and who accepts lender-set guidelines.
If you are weighing a cash-out refinance against keeping the loan you have, Lendmire can help you compare the programs and the equity each one reaches.
For your own numbers, request a scenario review with Lendmire.
About Lendmire
Lendmire is a mortgage brokerage (NMLS# 2371349) licensed for consumer mortgage lending in 16 states, arranging FHA, VA, conventional and jumbo purchase and refinance loans through a wholesale lending network. Eligibility is determined by the lender on each file. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
For current guidelines, see jumbo loan programs.
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Informational only. Not a Loan Estimate, approval, or commitment to lend. Program availability and eligibility are subject to lender guidelines, credit approval, property review, and underwriting.
References
1. FHFA – Conforming Loan Limit Values for 2026
2. Fannie Mae Selling Guide B2-1.3-03 Cash-Out Refinance
3. Fannie Mae – Accessory Dwelling Units
7. CFPB – Using home equity guide
This article is part of Lendmire’s jumbo cash-out refinance program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How Broker Lanes Work for a Jumbo Cash-Out Refinance · Jumbo Cash-Out Refinance Requirements to Pay for Renovations · Can You Get Approved for a Jumbo Cash-Out Refinance in Six Months?
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
- Mortgage Loan Originator · NMLS# 1129696 · Verify on NMLS Consumer Access
- North Carolina Real Estate Broker · License# 343312 · Verify on NCREC
- North Carolina Insurance Producer · License# 19053198 · Property, Casualty, Life, Health · Verify on NAIC SBS
- Lendmire LLC · Firm NMLS# 2371349 · Verify firm licensure
Important disclosures. Lendmire (NMLS# 2371349) is a licensed mortgage brokerage. Lendmire is not a direct lender, depository institution, or financial advisor. All loan inquiries are subject to lender underwriting; this article does not constitute a commitment to lend. Rates, terms, and program guidelines are subject to change without notice and vary by borrower profile, property type, and state. Information in this article is general in nature and is not financial, legal, or tax advice. Equal Housing Opportunity. NMLS Consumer Access: nmlsconsumeraccess.org.