The Quick Read: The best program for your situation is the one whose vesting, leverage ceiling and draw structure fit the unit you are building, and on an investment property that choice is narrower than most investors expect. Across Lendmire’s wholesale network, an investment-property line is sized on today’s value, not the finished unit, and it is underwritten on the borrower rather than the rent.
- An investment-property line in the network tops out at 70% combined loan-to-value (CLTV), with a 700 minimum credit score and a maximum line of $500,000.
- The line is sized on the property as it stands today. The ADU you have not built yet adds nothing to the line.
- An LLC cannot hold title on these lines. Title must sit with the individual borrower or a revocable living trust.
- At least 75% of the line is drawn at closing, and pricing floats for the life of the line.
- Many investors use the line as a bridge. They finish and lease the unit, then move to a DSCR cash-out refinance that qualifies primarily on property-level rental income, subject to lender guidelines.
Lendmire is a mortgage broker. It places these files with select wholesale partners and is never the lender. Every figure below is subject to lender guidelines and full file review, and none is a commitment to lend.
How large a line the equity supports.
An equity line is sized by combined loan-to-value, occupancy, and credit — not by rental coverage. Switch the occupancy or the credit band and the ceiling moves with it.
Investment-property lines require a 700 minimum credit score; second-home lines start at a 640 minimum and primary-residence lines at 600, and the combined-LTV ceiling steps down as the credit band drops on primary-residence and second-home lines and holds on investment-property lines; the line cap steps down on primary-residence lines and holds at every tier on investment-property and second-home lines.
A debt-to-income ratio above 45% requires 680+ credit. Profiles under 640 are limited to single-family homes. At least 75% of the approved line is drawn at closing. Ceilings, floors, and caps update from Lendmire’s centralized guideline source.
Line estimate
Illustrative estimate only — not a quote, Loan Estimate, approval, or commitment to lend. The rate is an editable assumption; equity-line pricing is variable through both the draw and repayment periods and never converts to fixed. Occupancy and credit drive the ceiling together: an investment property tops out at 70% combined LTV (minimum credit 700, line cap $500,000); a second home tops out at 90% combined LTV (minimum credit 640, line cap $500,000), with the ceiling stepping down as the credit band drops (the cap holds at every tier); a primary residence tops out at 90% combined LTV (minimum credit 600), and its $750,000 maximum line is available only at 75% combined LTV or below with a 700-or-better credit profile (720 on the longer-runway program) and a full appraisal. Lines above $500,000 require a full appraisal. Credit, debt-to-income, property type, and full underwriting review all affect the final line.
What Is an Investment Property HELOC, and What Does It Do for an ADU?
An investment-property HELOC is a revolving line secured by equity in a rental. You borrow against the equity, then spend the money on the ADU. The line does not care what you build with it.
The line sits in first or second lien position. The lender sets a combined ceiling on the property’s current value, subtracts what you owe on the first mortgage, and the remainder is the most you can draw. A line on the rental is one structure. A line on your primary home, spent on the rental’s ADU, is another. The primary-home version carries higher leverage tiers, which is a separate topic. Lendmire’s piece Best HELOC Program to Build a Granny Flat or ADU covers that route.
Terminology matters less than people think. Granny flat, in-law unit, backyard cottage and ADU all describe a second dwelling on the same lot. The lender does not price the name. It prices the collateral, the borrower and the combined leverage.
Who finances ADUs with equity? The Urban Institute’s ADU financing paper draws on a survey of more than 800 California homeowners who built permitted ADUs. Of those, 43% used mortgage products, and 56% of that group used a HELOC or home equity loan. Those are California homeowners, not investors and not a national sample. Read the numbers as a direction, not a benchmark. The direction is that equity lines are the common route.
How Underwriting Treats the Line, Step by Step
Underwriting a HELOC looks at the borrower first and the property second. Rent coverage is not the test. Here is the sequence a file follows.
1. Collateral and vesting. The property must be titled in the borrower’s name or an inter vivos revocable living trust. LLCs, corporations, partnerships and irrevocable, blind or land trusts cannot hold title on these lines.
2. Valuation. Because an investment line caps at $500,000, and full appraisals begin only above $500,000, these files ordinarily run on an automated valuation with no traditional appraisal. A borrower can still request a full appraisal. Either way, the value is today’s value.
3. Line sizing. Take 70% of today’s value as the combined ceiling. Subtract the first mortgage. What is left is the room. A rental with a first mortgage at 55% of value has 15 points of value to work with. A rental at 60% has 10 points. The finished ADU is not counted in either case.
4. Borrower qualification. Debt-to-income is capped at 50%, and the lender qualifies the borrower on the interest-only payment calculated on the maximum draw. That is stricter than it sounds, because the test assumes the line is fully used.
5. Credit. The investment floor is 700. A 720 score reaches the same 70% ceiling, so credit above 700 buys eligibility rather than extra leverage. Lenders pull a single-bureau score keyed to the primary wage earner, and the report must be no more than 90 days old at closing.
6. Documents. A typical file carries the first-mortgage statement, the insurance declaration, the vesting deed and any lease or rent evidence the lender asks for. Missing vesting paperwork is a common reason these files stall.
7. Funding. At least 75% of the line is drawn at closing. After that, the minimum subsequent draw is $1,000 under the program that states one, except Texas at $4,000.
Step 7 is where ADU borrowers get surprised. The standard picture of a HELOC is a card you tap as invoices arrive. On this network, most of the line is drawn up front, and the interest-only payment runs on that balance from the start. If a build is staged across permits, foundation and framing, the carry begins long before the contractor needs the money. Budget for it, or size the line closer to the real build cost.
Why the Finished Unit Does Not Count
A common assumption is that the lender will credit the ADU you are about to build. It will not. Equity lines are sized on today’s equity. Only purpose-built renovation and construction products lend against after-improvement value, and the Urban Institute treats those as a separate category from the equity vehicles of HELOCs, home equity loans and cash-out refinances.
Renovation products also get little use. A California YIMBY summary of the same survey reports that only 6.3% of borrowers used renovation loans, even though those loans can lend against post-construction value. Investors tend to follow the same logic. The paperwork is heavy, so they take the equity line and accept the lower sizing.
Projected ADU rent is the second assumption to drop. Some lenders in the wider market consider it, but a Shelterforce report quotes Urban Institute fellow Laurie Goodman saying most ADUs are built by owners who qualify without counting future rent. Plan on qualifying on your current income and your current equity. Treat any rent from the new unit as a later benefit, not a qualifying input.
What the Market Reports Versus What This Network Offers
Investment-property lines are a thin product. NerdWallet’s guide to HELOCs on investment properties says not all lenders offer them, the lender pool is smaller, borrowing limits are lower than on a primary home, and some lenders restrict by location or by whether the home is rented year-round. It also reports a market-wide maximum near 80% loan-to-value, with many lenders sitting below 70%. That is a market statistic. On Lendmire’s network, an investment-property line is capped at 70% CLTV, with no tier above it.
That gap is the reason the program choice matters. Brokers see many lenders’ guidelines side by side. The right match depends on property type, credit profile, how much equity is left after the first mortgage, and how the property is titled. A broker can shop those variables across multiple wholesale lenders, while a single lender only offers its own terms.
Availability has one more limit. The HELOC platform runs in 16 full-service states only: AL, CA, CO, FL, GA, IN, MI, MT, NM, NC, OH, PA, TN, TX, VA and WA. That is narrower than the DSCR footprint of 40 states plus Washington, D.C.
Structure: Draw, Repayment and a Floating Line
The investment line runs one structure only. It carries a 5-year interest-only draw period, followed by a 25-year fully amortizing repayment period. Primary residences and second homes have a shorter draw option, but investment properties do not.
Pricing floats across both the draw period and the repayment period, and it never converts to fixed. The CFPB explains that after the draw period you can no longer borrow, and payments often rise significantly in repayment. It also notes that some HELOC plans allow a fixed-rate conversion on part of the balance. That option exists in parts of the market, but it is not part of this network’s investment line. A variable payment can change even when you draw nothing new, so a long build with a floating payment needs a cushion.
Texas has its own rules for primary homesteads, but a Texas investment property is eligible as a non-homestead transaction. New Mexico and Ohio apply a CLTV cap that depends on the credit profile. A property listed for sale, or listed within the past 60 days, is ineligible in NC, PA, TN, TX and WA.
Where the Rule Breaks: Named Edge Cases
Rental titled in an LLC. This is the sharpest edge. Lines require individual or revocable-trust vesting. A rental already deeded to an LLC needs a vesting change before a line can sit on it. The alternative is a DSCR cash-out, which can lend to an entity, subject to program terms.
Large builds. A line above $500,000 is available only on primary residences. It requires a 700 score or better (720 on the longer-runway structure), caps at 75% CLTV and requires a full appraisal. On an investment property, the cap is $500,000 and 70% CLTV, and nothing larger exists.
Thin equity. If the first mortgage already uses most of the 70% ceiling, there is no room to draw. A rental with a 70%-plus first mortgage has no line to offer. The options then are a different collateral property, a renovation product, or waiting for equity to build.
Property type. Single-family, 2-4 units, PUD, townhome and condominium, including non-warrantable condos, are eligible. Manufactured homes, co-ops, condotels, log homes, commercial, mixed-use and agricultural-zoned properties are not eligible.
Exposure. A borrower is limited to three lines. Combined exposure caps at $2,000,000 on the higher-leverage program and $750,000 on the longer-runway program. A borrower with more than 15 financed properties is not eligible.
Credit events. A bankruptcy needs 4 years of seasoning from discharge or dismissal. On investment files, a foreclosure follows a 7-year path and a short sale or deed-in-lieu follows 4 years.
Local rules. ADU zoning, permitting and rental rules vary by jurisdiction. Confirm that the unit can legally be built and rented before drawing on any line. This applies to short-term use as well, because rules vary by city, county, HOA and property type.
Line on the Rental or Line on Your Home?
| Factor | Line on the rental | Line on your primary home |
|---|---|---|
| Leverage ceiling | 70% CLTV | Higher tiers by credit |
| Maximum line | $500,000 | Above $500,000 possible |
| Draw structure | 5-year draw, 25-year repayment | Two structures available |
| Valuation | Usually automated | Full appraisal above $500,000 |
| Risk on failure | Rental is collateral | Home is collateral |
The primary-home line offers more leverage, but it puts your residence behind a rental project. That trade-off is personal. The rental line keeps the risk on the property being improved. Neither is better in the abstract. Investors with a paid-off home and a leveraged rental often lean toward the home line, and investors who want to keep the project self-contained lean toward the rental line.
The Exit: From the Line to a DSCR Cash-Out
A floating, interest-only line is a bridge. The typical investor sequence is to fund the ADU with the line, permit and finish the unit, lease it, then refinance into a DSCR cash-out that qualifies primarily on property-level rental income, subject to lender guidelines.
DSCR is the rent divided by the full monthly obligation: principal, interest, taxes, insurance and any HOA dues. Many select programs start at 1.00. A separate select-lender path takes coverage below 1.00, with leverage and terms adjusted. A stronger ratio opens better pricing and leverage. Clearing 1.00 is not the same as positive cash flow, because repairs, vacancy, management, utilities and capex sit outside the calculation.
Across most of the network, a DSCR cash-out tops out near 75% LTV on a standard rental, with about 6 months of seasoning as the common expectation. Credit expectations are different from the HELOC. A 620 floor exists in parts of the network, most programs want around 660, and 700 or better unlocks the strongest leverage tiers. Loan sizes run up to $3,000,000 on standard programs (smaller balances available through select lenders). Reserves vary by lender, leverage, loan size and transaction type, commonly around 6 months of PITIA. The complete DSCR loans guide covers the full set.
There is one practical catch. ADU rent is unproven until the unit is built. A DSCR refinance on in-place rent generally needs the unit finished and leased first.
A DSCR loan also serves a different borrower than a HELOC. A HELOC rewards personal credit and low debt-to-income. A DSCR cash-out rewards property rent coverage. An investor with many mortgages and modest personal income can fail the first test and pass the second. That is a structural difference, not a quality ranking.
How the Decision Looks in Practice
Picture an investor with a single-family rental titled in her own name. The first mortgage sits at about 50% of today’s value, her score is above 700, and her debt-to-income is well under 50%. The 70% ceiling leaves about 20 points of value. If the ADU build fits inside that room and the line stays under $500,000, the rental line is a clean fit, and the exit is a DSCR cash-out once the unit is leased.
Now consider an investor whose rental is deeded to an LLC, with a first mortgage near 65% of value. The line fails twice: the vesting is wrong, and the equity is too thin. A DSCR cash-out on the entity, or waiting until rent and equity grow, is the more realistic route.
The strongest files clear both tests: enough equity and enough rental coverage. A larger down payment lowers the monthly payment and can lift the DSCR, but it does not erase leverage caps, credit floors, reserve rules or property eligibility.
An experienced broker watches three things on these files. First is vesting, which is a document problem that is cheap to fix before submission and costly after. Second is the combined-leverage math, run before anyone orders plans. Third is the carry, because most of the line is drawn at closing and the payment floats.
Key Terms Defined
CLTV (combined loan-to-value): The total of all liens on the property divided by its value.
Draw period: The stretch when you can borrow from the line and pay interest only. On an investment line it lasts 5 years.
Repayment period: The stretch after the draw period ends, when you cannot borrow and the balance amortizes. It lasts 25 years on an investment line.
Vesting: How title is held. These lines require an individual or a revocable living trust, not an LLC.
As-is valuation: Sizing the line on the property’s value today, not its value after the ADU is built.
DSCR (debt service coverage ratio): Monthly rent divided by the monthly principal, interest, taxes, insurance and any HOA dues.
Frequently Asked Questions
Can a HELOC on an investment property fund an ADU?
Yes, the line can fund the build, but it is sized on the rental’s current value. On Lendmire’s network, an investment line reaches 70% CLTV, with a 700 minimum credit score and a maximum line of $500,000. The line does not care how you spend the proceeds, so the ADU is just a use of funds.
Will the lender count the ADU’s future rent or value?
Usually not. Equity lines are sized on today’s equity, and most ADU builders qualify without counting future rent. Only renovation and construction products credit post-completion value, and they are paperwork-heavy.
Can my LLC hold the property?
No. Title must sit with the individual borrower or an inter vivos revocable living trust. An LLC-titled rental needs a vesting change or a DSCR cash-out instead, subject to program terms.
How much of the line is drawn at the start?
At least 75% is drawn at closing, and pricing floats through the draw and repayment periods without converting to fixed. That means interest-only carry on most of the line begins right away. Size the line to the build, not to the maximum.
What happens when the unit is finished?
Many investors lease the unit and refinance into a DSCR cash-out. It qualifies primarily on property-level rental income, subject to lender guidelines, and a cash-out typically tops out near 75% LTV on a standard rental. Whether that works depends on the rent the finished unit produces and the file’s credit, reserves and property review.
If you are considering a home equity line and want to see how the numbers work, Lendmire can help you compare HELOC options based on the property, the equity available, credit profile, combined leverage, and your goals. Call 828-256-2183 or request a quote.
An ADU rewards the investor who sizes the line to the equity that exists today and plans the refinance before breaking ground.
About Lendmire
Lendmire is a mortgage brokerage (NMLS# 2371349) arranging home equity lines of credit — primary-residence, second-home and investment-property lines — through a wholesale lending network in its 16 full-service states. Eligibility is determined by the lender on each file. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
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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. Urban Institute – To Increase the Housing Supply, Focus on ADU Financing
2. California YIMBY – Much Ado About ADU Financing
3. Shelterforce – How Financing Barriers Keep ADUs Expensive
4. NerdWallet’s guide to HELOCs on investment properties
5. CFPB: What Is a Home Equity Line of Credit HELOC
This article is part of Lendmire’s investment property HELOC program — full qualification details, guidelines, and scenarios live on the program page.
Related reading: How to Qualify for an Investment Property HELOC Subordinated for a Refinance · How to Qualify for an Investment Property HELOC on One Income
Brandon Miller
Founder & CEO, Mortgage Loan Originator, Lendmire LLC
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Required disclosures. Lendmire (NMLS# 2371349) operates as a licensed mortgage broker, not a direct lender or depository. The discussion in this article is general in nature and should not be relied upon as financial, legal, or tax advice — every investment scenario is unique and should be reviewed by a qualified professional. Any loan inquiry is subject to lender underwriting, and this article is not a commitment to lend or a guarantee of approval. Mortgage rates, loan terms, and program guidelines vary by borrower, property, and state, and may change without notice. Equal Housing Opportunity. Verify licensure at NMLS Consumer Access.