What Is the Monthly Payment on a $300,000 Construction Loan?

It's one of the first questions almost every borrower asks, and it doesn't have a single answer — because a construction loan doesn't behave like a standard mortgage. Instead of one fixed payment from day one, your payment changes as your build progresses. Here's how it actually works, step by step.

Phase One: Interest-Only Payments During the Build

During construction, most construction-to-permanent loans charge interest only — and only on the funds actually drawn, not the full $300,000. If your builder has only drawn $60,000 for site work and a foundation, your interest payment is calculated on $60,000, not the full loan amount. As more draws release for framing, mechanicals, and finish-out, the balance you're paying interest on climbs along with the build.

That means your payment starts low — sometimes just a few hundred dollars a month — and gradually increases as more of the loan is disbursed. By the time your builder requests the final draw, you're paying interest on close to the full $300,000.

Phase Two: Conversion to Permanent Financing

Once construction is complete and a certificate of occupancy is issued, a construction-to-permanent loan converts automatically into a standard mortgage. At that point, your payment shifts from interest-only to standard principal-and-interest, calculated on the full $300,000 balance at whatever rate and term you locked in.

As a rough illustration: a $300,000 loan at a 30-year term and a typical rate in this space might land somewhere in the neighborhood of $1,800-$2,200 a month in principal and interest once converted — but that range moves a lot depending on your actual rate, term, taxes, and insurance. A lending partner matched to your specific situation can model real numbers against your rate and draw schedule; this is meant as a general shape of how the payment evolves, not a quote.

What Changes the Number

A few factors swing the final payment more than anything else: your interest rate (specialty and portfolio lenders on non-standard properties sometimes price a bit differently than a conforming conventional mortgage), your down payment (a larger down payment lowers the financed amount and the payment with it), and your loan term (a 30-year term spreads payments lower than a 15-year term, at the cost of more interest paid over time).

Property taxes and homeowners insurance, often escrowed into your monthly payment, also affect the final number — and those vary significantly by county and by property type (a barndominium or acreage parcel may carry different insurance considerations than a standard subdivision home).

Getting a Real Number

The only way to get an accurate monthly payment estimate is to run your specific rate, term, down payment, and draw schedule against a real lender's numbers. Cabin Home Loan connects you with specialty and portfolio lending partners who can walk through both the interest-only build-phase payment and the permanent-phase payment for your exact project, at no cost and with no obligation.