The Quick Read: A standard cash-out refinance is sized on what your home is worth today, not on what it will be worth after the addition. On a one-unit primary residence, conventional cash-out tops out at 80% of current value, and payoff, closing costs and prepaids come off before you see a dollar. If today’s equity can’t cover the project, a renovation mortgage sized on as-completed value is the other route. All figures are subject to lender guidelines and full file review.
The sizing question is a budget problem first and a lending problem second. Start with what the project costs. Then work backward to the loan that can pay for it.
What Does a Cash-Out Refinance Actually Do?
A cash-out refinance replaces your current first mortgage with a larger one. The new loan pays off the old balance, covers closing costs, and hands you the difference in cash. You get one loan, one payment, and a new rate and term on the entire balance.
That last point matters for an addition. Your old rate disappears. A CFPB guide on using home equity notes that a cash-out refinance may lengthen your payoff time and raise your monthly payment, because the new loan’s terms replace the old loan’s.
The money arrives as a lump sum at closing. Nobody inspects the work or releases funds in stages. That is the main structural difference from a renovation mortgage, covered below.
Across the wholesale programs Lendmire works with, the cash-out lane is the simplest to arrange for an addition when the homeowner already has plenty of equity. It gets complicated when the equity is thin. Lendmire’s cash-out refinance programs cover the conventional lane described here.
Key Terms Defined
As-is value: What an appraiser says the home is worth today, before any work.
As-completed value: What an appraiser projects the home will be worth once the plans are built.
LTV (loan-to-value): The new loan balance divided by the home’s value, shown as a percentage.
Seasoning: The minimum time you must have owned the home, or held the existing mortgage, before a cash-out refinance is available.
ADU (accessory dwelling unit): A separate living space on the same parcel with its own sleeping, cooking and bathroom facilities.
Prepaids: Up-front deposits for items like homeowners insurance and property taxes that come out of your proceeds at closing.
How Do You Size the Loan, Step by Step?
Size the loan from the project backward, then check it against the lending cap. Most homeowners do it the other way around and get surprised at closing. Work these steps in order.
1. Build the all-in budget. Add hard costs (construction), soft costs (design, engineering, permits), utility connections, and a contingency cushion. Overruns on additions are routine, so leave room.
2. Pick the value basis. A standard cash-out uses as-is value. A renovation mortgage uses as-completed value. This choice drives everything after it.
3. Apply the LTV cap. On a one-unit principal residence, conventional cash-out reaches 80% of value. On a two- to four-unit principal residence, it reaches 75%. Multiply the cap by the value basis to get the maximum new loan.
4. Subtract the payoff. Take the maximum loan and subtract your existing first mortgage balance, plus any other liens that must be cleared.
5. Subtract closing costs and prepaids. This is where gross cash-out becomes net spendable cash. Costs apply to the whole new balance, not just the cash portion.
6. Compare net cash to the budget. The result is either a cushion or a gap. Be honest about it.
7. Stress-test the payment. Look at the new total payment against your income and other debts. Lenders review debt-to-income, and so should you.
Cash-out available is not simply value minus balance. The LTV cap, the payoff and the closing costs all come off first. A homeowner who skips steps four and five will overestimate spendable cash.
As-Is vs. As-Completed: The Decision That Sets Your Ceiling
Most homeowners assume they can borrow against the finished addition with a plain cash-out. They can’t. A standard cash-out is sized on current appraised value. Only a renovation mortgage uses the value after the work.
| Factor | Standard cash-out | Renovation mortgage |
|---|---|---|
| Value basis | As-is appraisal | As-completed appraisal |
| How funds arrive | Lump sum at closing | Held and released in draws |
| Cash to borrower | Yes, after payoff and costs | Only for the work |
| Project paperwork | Light | Bids, plans, permits |
| Best fit | Ample equity today | Thin equity, value-adding project |
Fannie Mae’s HomeStyle Renovation eligibility rules show the as-completed logic. On a refinance, eligible renovation costs are capped at 75% of the as-completed value, and the LTV is measured against that same as-completed figure. A Maximum Mortgage Worksheet (Form 1035) does the math.
This is a genuine toss-up for many homeowners. Strong equity and a modest project favor the plain cash-out: less paperwork, no draw schedule. Thin equity and a project that adds real value favor the renovation loan, since the as-completed basis can support more than today’s value allows.
How Does the Renovation Route Work in Practice?
Renovation loans trade flexibility for structure. Fannie Mae’s HomeStyle product sheet says the borrower cannot take cash back at closing in any amount on this product. The standard limited cash-out allowance does not apply. Funds go toward the work, and a documented contractor deposit can be reimbursed.
The mechanics look like this:
- The lender needs contractor bids, plans and permits up front.
- The appraiser produces an as-completed value from the plans.
- Renovation money sits in a custodial account. The lender manages draws and a final inspection.
- Title and liens must be clear before the last funds release.
- The product sheet cites a completion window of fifteen months.
- Do-it-yourself labor is capped at 10% of as-completed value, and sweat equity can’t be reimbursed.
- Manufactured homes face a lower renovation cap, at 50% of as-completed value.
The lender has to be approved to deliver these loans, and not every wholesale lane offers them. That limits your options. If this path fits, ask early whether a lender on the file handles renovation loans before the budget hardens around it.
Freddie Mac has a parallel product. Its ADU fact sheet says CHOICERenovation can fund a new ADU or renovation of an existing one on a purchase or refinance, with one ADU allowed on one- to three-unit properties. The ADU must comply with local zoning and an appraisal is required.
Where the General Rule Breaks
The sizing steps above hold for most files. These edge cases are where they stop working.
Seasoning. Conventional cash-out requires the first mortgage you’re paying off to be at least 12 months old, note date to note date. You also need six months on title, with exceptions for delayed financing, inheritance and legal award. Freddie Mac’s Guide section 4301.5 spells out both. A homeowner who bought recently and plans to build right away often runs into this wall.
What counts as an ADU. Not every detached building qualifies. Fannie Mae’s special property eligibility rules define an ADU as living area on the same parcel with its own sleeping, cooking and bathroom facilities. A workshop or storage building without those is an ancillary structure. Appraisal treatment differs.
Unit count. A home with one primary dwelling and an ADU is generally classified as a one-unit property under Fannie Mae’s appraisal policy. That matters because the one-unit cash-out cap is higher than the cap for two to four units.
Government loans. An FHA Streamline and a VA IRRRL exist to lower the payment on an existing loan. Neither returns equity, so neither funds an addition. The FHA route is a 203(k) rehabilitation loan or an FHA cash-out. The VA route is a VA cash-out. HUD’s 203(k) consumer fact sheet says building permits must be in hand before work starts, and a consultant is required on the Standard version for structural work.
Rental income from the ADU. Whether ADU rent can help you qualify depends on the program and the transaction. Don’t plan around it until a lender confirms in writing how that file will be treated.
Texas. A cash-out on a Texas homestead is capped by the state constitution, and the wholesale 89.99% lane isn’t written there.
What About the Higher-Leverage Cash-Out Lane?
Conventional cash-out to 80% on a one-unit primary residence is the baseline. Across the wholesale programs Lendmire places files with, one lane reaches 89.99% LTV with no mortgage insurance. It requires a 680 score, a 50% ratio and a thirty-year fixed on a primary residence with a conforming balance, plus its own six months of seasoning. It is not available in Texas. Final terms follow the full file review. Leverage, reserves, and pricing vary by lender and program; the final terms follow the full file review.
For an addition, that extra leverage can close a funding gap on a smaller project. It is a narrow lane with firm conditions, so treat it as one option to test, not an assumption. Qualification is subject to lender guidelines and full file review.
Two Worked Examples
Surplus case. Say a homeowner has a one-unit primary residence with a low existing balance relative to value. The project is a bump-out addition. At the 80% cap, the maximum loan, less payoff and closing costs, still leaves net cash above the full budget including contingency. A standard cash-out fits, and the decision turns on whether the new payment is comfortable.
Shortfall case. Now take a homeowner with a larger balance who wants a detached ADU. At 80% of today’s value, the payoff and closing costs eat most of the cash. Net proceeds land well under the budget. Three options exist: shrink the scope, bring savings, or look at a renovation mortgage sized on as-completed value. The third only works if the as-completed appraisal supports it, and if no cash back is acceptable.
The shortfall case is the more common one. Run it before you sign a contractor.
Appraisal Risk and Cost Overruns
A low appraisal shrinks the loan. On a standard cash-out, the as-is number is what it is. On a renovation loan, the as-completed value rests on your plans and bids, so thin plans produce a thin value. Build a margin: aim for a budget that still works if value comes in modestly lower.
Funds timing is its own risk. A cash-out pays everything at closing, and interest runs on the whole balance from day one. That cash needs to sit somewhere until contractors are paid. A renovation loan solves the timing but adds draws and inspections.
If costs overrun mid-build, a cash-out gives you no more money. Contingency is the only protection. A renovation loan has a reserve rule on two- to four-unit homes (10% of renovation costs), though none is required on a one-unit property, per Fannie Mae’s HomeStyle FAQ.
What Does It Cost You Beyond the Project?
Cash-out refinancing draws down your equity. The CFPB’s research on cash-out refinances notes that converting other debts into mortgage debt can put the home at risk of foreclosure, and that the borrower is spending current wealth. Owning less of your home is the price of the cash.
Weigh the break-even honestly. Replacing a whole first mortgage to fund one project makes sense when the old loan isn’t a bargain or the equity is large. If your existing terms are favorable, a second-lien option may cost less on the incremental money. Cash-out is not the only tool, and the comparison belongs on your worksheet.
Tax treatment can depend on your situation; borrowers should speak with a qualified tax professional before relying on any deduction or credit.
Borrowers weighing the bank question can also read Lendmire’s comparison of where to cash out refinance a home.
Common Mistakes
- Assuming the finished addition counts toward value on a plain cash-out.
- Treating gross cash-out as spendable cash.
- Skipping contingency.
- Counting projected ADU rent before a lender confirms it.
- Ignoring seasoning on a recent purchase.
- Starting construction before permits are in hand.
Frequently Asked Questions
Can I borrow against what my home will be worth after the addition?
Only with a renovation mortgage. A product like Fannie Mae’s HomeStyle uses the as-completed value, with eligible renovation costs capped at 75% of it on a refinance, though you can’t take extra cash back.
Why is my cash-out smaller than my equity?
Equity isn’t the same as cash. The LTV cap limits the new loan, then your existing mortgage payoff, closing costs and prepaids come off. What remains is net spendable cash, and it is often noticeably less than value minus balance.
Can an FHA Streamline or VA IRRRL fund an addition?
No. Both are built to lower payments on an existing loan and don’t return equity as cash. FHA borrowers look at a 203(k) or an FHA cash-out. VA borrowers look at a VA cash-out. Eligibility is subject to lender guidelines.
Do I need to have owned the home for a certain time?
Usually, yes. Conventional cash-out requires the mortgage being paid off to be at least 12 months old and a borrower on title for six months. Exceptions exist for delayed financing, inheritance and legal award.
Will rent from the ADU help me qualify?
It depends on the program and the transaction. Some programs address ADU rental income under separate rules, and others don’t count it. Get the treatment confirmed on your specific file before you plan around it.
Next Step
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. Run your project budget through the steps above before choosing a path. Nothing here is a commitment to lend.
For your own numbers, request a scenario review with Lendmire.
For current guidelines and terms, see Lendmire’s refinance programs page.
About Lendmire
Lendmire (NMLS# 2371349) is a mortgage broker licensed for consumer lending in 16 states. Lendmire arranges FHA, VA, conventional and jumbo purchase and refinance loans through wholesale lenders; every file is underwritten by the lender under the applicable program guidelines. Scotsman Guide named Lendmire a Top Mortgage Workplace in both 2025 and 2026.
Get Started
Ready to find the right loan for you?
In about 30 seconds you can review financing options available for your home or investment property. No commitment required.
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. CFPB, using home equity guide
2. Fannie Mae Selling Guide B5-3.2-02, HomeStyle Loan and Borrower Eligibility
3. Fannie Mae HomeStyle Renovation product sheet
5. Freddie Mac Guide section 4301.5, Cash-out refinance
6. Fannie Mae Selling Guide B2-3-04 Special Property Eligibility
8. CFPB, research on cash-out refinances
This article is part of Lendmire’s Refinance series — every loan program’s qualification details, guidelines, and scenarios live on the loan options page.
Related reading: How to Get a Cash-Out Refinance on a Paid-Off Home in Retirement · Should You Use a Cash-Out Refinance to Build an Addition or ADU? · How to Size a Cash-Out Refinance to Consolidate Card Debt
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
Disclosure information. Lendmire is a state-licensed mortgage brokerage under NMLS# 2371349. Lendmire is not a depository institution, direct lender, or financial advisor — all loans referenced are placed through wholesale lender partners and are subject to each lender's underwriting standards. This article is provided for general informational purposes and is not a commitment to lend, nor does it constitute financial, legal, or tax advice. Loan programs, terms, rates, and qualification standards change without notice and depend on borrower profile, property type, and the state in which the subject property is located. Equal Housing Opportunity provider. NMLS Consumer Access: nmlsconsumeraccess.org.