Do I pay interest during the construction phase of a construction loan?

The interest applies only to the money you have actually drawn, not the full loan amount. While the home is being built you make interest-only payments. You are not paying down principal yet. Because the lender releases the loan in stages, your outstanding balance grows as construction moves forward, so each payment is a little larger than the last. When the build finishes, the loan either converts to a permanent mortgage or is paid off, and only then do you start paying principal. Rates and terms vary by lender and change often, so confirm your numbers with your lender.

How interest works while the home is being built

You pay interest only on the funds advanced so far, and only for the time those funds are outstanding. A construction loan does not hand you the whole amount on day one. The Consumer Financial Protection Bureau (CFPB) explains that the money "is typically provided in a series of advances as the construction progresses." Each advance is a draw, released when the home hits a set milestone like foundation, framing, or drywall. You can see how those milestones line up in our draw schedule glossary entry.

Interest is charged on the balance you have drawn, not the loan's full size. Federal mortgage rules describe this directly. Under Regulation Z, Appendix D, a lender may compute interest "only on the amount actually advanced for the time it is outstanding." So if your loan is approved for $500,000 but only $120,000 has been drawn, you pay interest on the $120,000, not the half million. This is the single most important thing to understand about construction-loan interest, and it is why early payments are small.

During this phase you make interest-only payments. You do not reduce the principal. That keeps your monthly cost lower while you may also be paying rent or an existing mortgage, which matters because you are carrying two housing costs at once until you move in.

Why your payment rises with each draw

Your interest-only payment increases over the build because the outstanding balance grows each time a draw is released. More money drawn means more balance accruing interest, so the payment steps up at each stage. The CFPB commentary on multiple-advance loans notes that the periodic payment can change "due to changes in the amount of the principal balance to which the interest rate is applied," even when the rate itself has not moved.

Picture the curve. Early on, only the lot and foundation draws are out, so the balance and the payment are low. By the time framing, mechanical systems, drywall, and finishes have all been funded, most of the loan is outstanding and the interest-only payment is near its peak. The last month of construction usually carries the largest payment of the whole phase.

This pattern has a planning lesson. Budget for a rising payment, not a flat one. The figure your lender quotes for the first month is not what you will pay in the final month. Ask the lender to walk you through estimated payments at each major draw so you are not surprised when framing and finishes hit at once.

Interest reserves and how lenders handle the cost

Some lenders set aside part of the loan to cover construction-phase interest, so you may not write a check every month. This is called an interest reserve. The CFPB describes it as a portion of the loan a lender may designate "to be used for paying the interest that accrues on the loan." Instead of billing you, the lender draws from the reserve to pay the interest as it adds up.

An interest reserve sounds convenient, and it can be, but understand the trade-off. The reserve is still your borrowed money. Interest paid from it increases your total loan balance, so you are financing the interest rather than paying it out of pocket. If the build runs long, the reserve can run dry before completion, and then you start making payments directly. Ask your lender whether your loan uses a reserve, how it is sized, and what happens if construction takes longer than planned.

Not every loan uses a reserve. Many Arizona borrowers simply pay the interest-only bill each month from their own funds. Both approaches are normal. The right one depends on your cash flow and how long you expect the build to take, so it is a direct question for your lender at application.

Some loan programs change who carries the construction-phase interest entirely. With a VA single-close construction loan, the structure can shift the cost off the veteran during the build. The VA explains that on these loans veterans "don't have to make payments on their home loan until after construction is complete," and the first principal payment may be postponed up to one year, while the builder handles interest and the usual interim-construction fees during the build. That is a program-specific perk, not the general rule, so it only applies if you qualify and your lender offers it. The point is that the interest exists either way; the program decides who pays it and when.

What drives the total interest you pay during the build

Your total construction-phase interest depends on three things: how much you draw, how long the build takes, and your rate. You control or influence the first two more than you might think. A faster build means fewer months of accruing interest. A draw schedule that releases money close to when each phase is actually done, rather than too early, keeps the balance from running up before the work needs it.

The build's length is the biggest lever. A custom home in the Phoenix metro often takes several months to a year to build, and every extra month adds interest on a balance that is mostly drawn by then. Weather delays, change orders, and material backorders all stretch the timeline and the interest with it. This is one more reason a realistic schedule and a builder who keeps the job moving save you money, not just time.

You cannot control the market rate, and it changes often, so do not anchor on a number you read today. Focus on the parts you can manage: a tight build schedule and a draw schedule that matches real progress.

What changes when the loan converts

Once the home is finished, the loan stops being interest-only and you begin paying principal. At that point a construction loan follows one of two paths. A construction-to-permanent loan converts automatically into a regular mortgage, and you start making normal payments that pay down both principal and interest. A standalone construction loan must be paid off, usually by closing a separate permanent mortgage, which can mean a second set of closing costs.

The CFPB warns that conversion is not always automatic and that with some loans you may have to reapply for the permanent financing. That is a real risk worth confirming up front, because if you cannot qualify for the takeout mortgage when the build ends, you can be stuck with a balance due. Ask whether your loan is single-close (one closing, automatic conversion) or two-close (two closings, requalify) before you sign.

Construction-loan rates are also typically higher than a standard mortgage and they move with the market, so no honest answer can quote you a fixed rate as a fact. The reliable takeaways are structural, not numeric: you pay interest-only during the build, only on the drawn balance, with a payment that climbs draw by draw, until the loan converts or is paid off. Get your specific rate, draw schedule, interest-reserve terms, and conversion path in writing from your lender, since these details vary by lender and change with the market.

How Jematell Homes helps

We build the budget line by line so the number you sign is the number you build to. If you are planning a custom home in Scottsdale, Rio Verde, or the greater Phoenix metro, we are happy to walk through your project.

Sources

• CFPB: What is a construction loan?
• CFPB Regulation Z, Appendix D (Multiple-Advance Construction Loans)
• CFPB Regulation Z, Appendix D Commentary
• VA News: VA offers construction loans for Veterans to build their dream homes