Construction-to-Permanent Loans Explained: How One-Time-Close Financing Works

A one-time-close (construction-to-permanent) loan closes the construction financing and permanent mortgage together before the build, then converts to long-term financing when construction is complete. The lender manages construction disbursements, and conversion still depends on completion and the program's eligibility and documentation rules, including any required requalification (Fannie Mae single-closing guide).

Policy sources checked as of November 3, 2026. Agency requirements below are not a lender approval or a quote. Confirm the applicable program and lender terms for your project.

CustomHomeLenders.com is a free referral service, not a lender. We match you with construction-loan specialists who set the actual terms.

The quick answer

• One application, one closing. You qualify and close before construction starts.
• Two phases in one loan. A construction phase, where money is released in draws and payments follow the loan agreement, and a permanent phase, where the loan amortizes like a regular mortgage.
• The conversion happens when the home is finished and the lender has confirmed completion.
• Programs differ on rate locks, modifications and requalification. Ask for the specifics in writing.

Official source: Fannie Mae single-closing overview; checked November 3, 2026.

How a C2P loan works, step by step

1. Application and underwriting. The lender reviews your credit, income, assets and debts, your builder, and your plans and budget. The appraiser values the home as if it were already built, based on the plans and specifications (an "as-completed" appraisal).

2. Closing. You sign one set of loan documents. At this point you've committed to the loan amount, the construction terms and, depending on the program, either a permanent rate or the method for setting it. Unlike a standard purchase, no finished home exists to inspect yet.

3. The construction phase. The lender holds the funds and releases them in draws as the builder reaches milestones. Typically the builder requests a draw, the lender confirms the work (often through an inspector), and money is released to the builder. The number and size of draws is set in your construction agreement. See our draw schedule guide.

4. Interest during construction. With an interest-only construction structure, payments cover interest on the amount drawn and do not reduce principal. Not every single-close product uses that structure: USDA documents an interest-only option and a securitized option with full principal, interest, taxes and insurance payments (USDA single-close fact sheet). Some budgets include an interest reserve that pays this interest from the loan; ask whether yours does. The Consumer Financial Protection Bureau notes that interest-only payments cover interest and don't reduce principal.

5. Completion and conversion. When the home is finished, the lender typically requires proof of completion, such as a certificate of occupancy and a completion report confirming the work matches the plans. For loans sold to Fannie Mae, that completion report is the applicable appraisal completion documentation, which may include Form 1004D. Then the loan converts to a permanent mortgage, and principal-and-interest payments begin.

Official source: Fannie Mae disbursement and completion rules; checked November 3, 2026.

Time limits on the construction phase

Lenders cap how long the construction phase can run. For single-closing C2P loans that will be sold to Fannie Mae, Fannie's Selling Guide limits the construction period to no more than 18 months in total, with no single construction period longer than 12 months, and the permanent term can't exceed 30 years. A portfolio lender may set different limits, so ask each lender what its construction period is, what happens if you run over, and what an extension costs. Weather, permitting and supply delays are the usual reasons builds run long.

Official source: Fannie Mae construction-period and permanent-term limits; checked November 3, 2026.

How the interest rate works

This is the part of a C2P loan people most often misunderstand.

The construction-phase rate. Many construction loans use a variable rate tied to an index, with a margin on top. If a variable rate applies, ask which index the contract uses. Ask which index, what margin, and whether the rate has caps or floors.

The permanent rate. Depends on the product:

• Locked at closing. Some programs let you lock the permanent rate when you close, which gives certainty but may come with a lock period that must cover the entire build, and a fee if you need an extension.
• Locked later or floated. Other loans let you wait to set the rate closer to conversion, which exposes you to market moves.
• Float-down or modification. A float-down lets you take a lower rate if the market drops, often for a fee. Fannie Mae's guidelines for single-closing loans allow a modification before conversion, but limit it to the interest rate, loan amount, term and converting an adjustable rate to a fixed rate. FHA construction-to-permanent loans use a rate-float agreement that sets the maximum permanent rate.

Rate-lock rules and fees are lender-specific and change over time, so get the terms in writing. For benchmark data, see construction loan rates and our interest rate guide.

Official source: HUD Handbook 4000.1 II.A.8.j: FHA rate-float and escrow rules; checked November 3, 2026.

"One-time close" doesn't mean "no requalification, ever"

A common claim is that a C2P loan eliminates the risk of not qualifying later. That overstates it. You do get through underwriting once, up front, which is a real benefit compared to a two-close loan. But the lender still has to confirm that the home was built as planned, and requalification can still be triggered. Under Fannie Mae's Selling Guide for single-closing loans, a borrower must be requalified at conversion if the loan-to-value ratio rose because the completed home appraised for less than expected, if updated credit documents had to be obtained (for example, because the original ones aged past the allowed window), or if modified loan terms fall outside the program's re-underwriting tolerances. The appraiser's completion report must also certify that the work is finished. Keep your finances stable during the build: no new large debts, and no job changes without telling your lender.

The loan amount can increase before conversion only in limited cases, such as documented higher construction costs under the program's rules. Plan for a contingency instead of counting on that. See construction loan contingency reserves.

Official source: Fannie Mae modification and requalification rules; checked November 3, 2026.

C2P vs. a two-time-close construction loan

Neither is always better. A C2P loan suits people who want certainty and one set of closing costs; a two-time close can suit buyers who expect their circumstances to change or who want to shop for the permanent loan later. Read more about one-time-close loans and the construction-to-permanent program.

Official source: Fannie Mae single-closing transaction rules; checked November 3, 2026.

C2P variants: conventional, FHA, VA, USDA

• Conventional C2P loans are an option, with rules that depend on the lender and, if the loan will be sold, the investor's guidelines such as Fannie Mae's.
• FHA construction-to-permanent loans have specific rules, including a requirement that the builder be a licensed general contractor and that funds be drawn from escrow with the borrower's written authorization. See FHA construction loans.
• VA and USDA options exist for eligible borrowers and locations. See VA and USDA construction loans.

Official source: HUD Handbook 4000.1 II.A.8.j: construction-to-permanent requirements; checked November 3, 2026.

Who a C2P loan fits

• Buyers building on land they own or are buying with the build, who want to qualify once.
• Borrowers who want to know the shape of their permanent loan before construction starts.
• People working with an experienced licensed builder and a well-defined set of plans and budget.

It may be a worse fit if you're acting as your own builder (many lenders won't allow it; see owner-builder loans), if your plans or budget are still changing, or if you might sell or refinance soon after finishing.

What to ask a lender before you commit

1. Is the permanent rate locked at closing? For how long, and what does an extension cost?
2. Is there a float-down or rate modification, and what does it cost?
3. How long can the construction phase last?
4. How are draws requested, inspected and funded? Are there draw or inspection fees?
5. Is there an interest reserve in the budget?
6. Under what conditions would you requalify me before conversion?
7. What happens if the final appraised value is lower than expected?

Next steps

Use the construction loan calculator to see how the interest-only phase and permanent payment differ. Get a cost estimate for your build from CustomHomeQuote, and read CustomHomeAdvisor's guide on how to choose a custom home builder before you sign anything.

Get matched with a construction-to-permanent lender → Free, no obligation.

Frequently Asked Questions

What is a construction-to-permanent loan?

A construction-to-permanent (C2P) loan finances the construction of your home and then converts to a long-term mortgage after completion, with a single application and closing. It's also called a one-time-close or single-close construction loan.

Is a C2P loan the same as a one-time-close loan?

Yes. "One-time close," "single close" and "construction-to-permanent" all describe a loan that covers the build and the permanent mortgage in one closing. "Two-time close" is the opposite: a separate construction loan followed by a separate mortgage.

How does the interest rate work on a C2P loan?

During construction, many loans use a variable rate based on an index plus a margin, and you pay interest on the drawn balance. The permanent rate is set by the program: it can be locked at closing, set later, or adjusted before conversion through a float-down or modification. Ask for lock length, extension cost and modification rules in writing.

Do I have to requalify when the loan converts?

Not necessarily, but don't assume you never will. You're underwritten up front, yet for loans sold to Fannie Mae, requalification is required at conversion if the final value is lower and raises the loan-to-value ratio, if updated credit documents were needed, or if loan changes exceed re-underwriting tolerances. Keep your finances stable during the build.

How long can the construction phase last?

It depends on the lender. For single-closing loans sold to Fannie Mae, the construction period is limited to 18 months in total, and no single construction period can exceed 12 months. Other lenders set their own limits.