Financing a custom build is a timing exercise wrapped in paperwork. As of mid-July 2026, Freddie Mac’s July 9 survey put the average 30-year fixed mortgage at 6.49% and the 15-year fixed at 5.82%, and the Federal Reserve held its federal-funds target range at 3.5% to 3.75% on June 17. Keep both figures in perspective. The survey tracks the national conventional market, not construction loans, and the Fed’s policy rate shapes financing conditions without being a consumer mortgage product. Nobody can tell you where rates will sit the month your roof goes on, so this guide focuses on what you can actually control, the loan structure and the timeline.
What Makes a Construction Loan Different
The Consumer Financial Protection Bureau defines a construction loan as short-term financing that is generally priced above a longer-term home mortgage, with money advanced in stages as the work progresses. Those stages are the draws. Your builder completes foundation, framing, or mechanical milestones, the lender inspects, and funds are released against completed work. The CFPB also flags the detail that trips up borrowers. If the loan does not automatically convert to permanent financing, you may have to reapply when the house is done, at whatever rates and terms exist then.
From the builder’s side of the table, the draw schedule is more than an accounting formality. It sets the rhythm of the project. A draw schedule that matches how the house actually gets built keeps subcontractors paid on time and the schedule moving, while a poorly matched one creates friction at exactly the moments a project can least afford it. Review it with your builder before you sign, not after the first inspection stalls.
Single Close or Two Closes
Fannie Mae describes single-closing construction-to-permanent financing as one transaction. The lender underwrites and closes the construction phase and the permanent phase at the same time, using one set of closing documents. Under Fannie Mae’s current single-close rules, updated May 6, 2026, no individual construction period may exceed 12 months, the total construction period may not exceed 18 months, and the loan cannot be purchased by Fannie Mae until construction is complete and the loan has converted to permanent financing.
The alternative is a construction-only loan followed by a separate permanent mortgage. Freddie Mac notes that this route can mean two applications and two sets of closing costs, with conversion financing using permanent-mortgage proceeds to pay off the interim construction loan once completion requirements are met. Two closes are not automatically worse. They can suit a client who wants to shop the permanent loan later or who needs construction terms a single-close lender will not offer. You are paying for flexibility, and the point is to know exactly what that flexibility costs before choosing it.
The Rate-Lock Problem on a Build Timeline
Typical mortgage rate locks last 30, 45, or 60 days. A custom build takes many months. That mismatch is the core planning problem in construction financing. The CFPB warns that lock extensions may cost money, that a lock can prevent you from benefiting if rates fall, and that changes to your application can alter a locked rate. On a single-close loan, ask precisely how the permanent rate is set, whether it is fixed at closing or at conversion, and what an extension or float-down costs. On a two-close structure, the permanent-loan lock only matters near completion, which shifts the entire risk window to the end of the build, right when schedule slip is most likely.
Coordinate These Five Things Before You Close
These five items decide whether your closing date and your groundbreaking date cooperate. Work through them with your builder and your lender in the same conversation whenever you can, because each one constrains the others.
- Design completion. Lenders underwrite against final plans and a firm construction contract. Late redesigns reopen underwriting and burn lock days you cannot get back.
- The appraisal. A construction appraisal values a house that exists only on paper, from plans and specifications. The more complete the documents, the fewer surprises in the valuation.
- Contingencies. Build your contingency into the loan amount at closing rather than hoping change orders fit inside the budget later.
- Construction duration. Your builder’s schedule has to fit inside the loan’s construction window with a weather cushion. Fannie Mae’s 12-month and 18-month limits on single-close loans are hard edges, not suggestions.
- The lender’s lock and extension rules. Get extension fees, float-down terms, and conversion mechanics in writing before you sign, not when the clock is already running out.
What to Lock, What Can Float
Here is the short version we give clients. Lock the things that are expensive to change, meaning the loan structure, the construction window, the documented budget, and the conversion mechanics. Let the market variables float until the structure makes them safe to fix. A well-built single-close loan secures certainty of conversion even while the rate question stays open, and a deliberate two-close plan leaves the permanent rate floating on purpose rather than by accident. Freddie Mac’s weekly survey is a fine benchmark for watching the market, but compare lender-specific construction terms rather than headlines. The July 9 reading of 6.49% describes the national conventional market on one Thursday. It is not the loan you will sign.
A financing timeline works best when it is built alongside the construction schedule, not bolted on after it. If you are planning a custom home in Western North Carolina, talk with the Big Hills team early and we will help you line up design milestones, builder schedule, and loan structure so every piece closes in the right order.
