Mortgage Rate Buydowns Explained: How 2-1 Buydowns and Discount Points Work for Charleston Buyers

If you have shopped new construction in Cane Bay, Nexton, or anywhere across the Charleston Tri-County, you have probably seen a builder advertise a rate buydown and wondered what it actually means in dollars. The honest version is not complicated: someone pays money at closing so that your mortgage payment behaves as though your rate were lower for a set period, or for the life of the loan. This guide explains the two common shapes, what each costs, who typically pays, and how to decide whether an offer is genuinely good for you.

I am Denise Rush, a REALTOR® with EXIT Realty Lowcountry Group serving Charleston, Berkeley, and Dorchester counties, where I spend much of my week comparing new-construction offers for buyers. Everything here is general education; rates, buydown costs, and lender terms are estimates that change daily, so run every number through your own lender's Loan Estimate before you sign anything.

What is a rate buydown?

A buydown is a lump sum funded at closing and held in an account the mortgage servicer draws from each month to supplement your payment. Your actual note rate never changes, and your loan balance never changes. What changes is your payment for a set period, and where the money to make that happen came from.

The two common shapes: temporary and permanent

The 2-1 buydown, the builder favorite

In a 2-1 buydown, your payment in year one is calculated as if your rate were two percentage points lower, and in year two as if it were one point lower. In year three it steps up to the full note rate, where it stays for the rest of the loan. A 3-2-1 variant spreads the reduction over three years before reverting in year four, and smaller 1-0 and 1-1 versions exist. Temporary buydowns are about cash flow in the early years, not a lower lifelong rate.

Discount points, the permanent version

A permanent buydown uses discount points paid at closing. One point costs one percent of the loan amount and typically reduces the rate by about a quarter of a percentage point for the entire loan, within a lender-specific range. On a $300,000 loan, one point is $3,000 for roughly a 0.25 percent reduction that lasts as long as the loan does. Over a long ownership that saving compounds; over a short one it may never pay for itself.

What does a buydown cost?

The cost of a temporary buydown is the size of the subsidy that has to be funded at closing, roughly the difference between what your payments would be at the note rate and what they are during the reduced-rate years. As a rule of thumb, a 2-1 buydown runs in the neighborhood of two percent of the loan amount, with published examples in the $7,500 to $11,600 range depending on loan size. Industry data on builder concessions, from John Burns Research and Consulting, finds builders commonly budget on the order of two percent of the home's price on incentives like buydowns. A permanent buydown runs about one percent of the loan per quarter-point of reduction.

Who actually pays for it?

In new construction, the builder almost always funds the buydown as the incentive, which is why you see it advertised at all. In a resale, a seller can offer a buydown concession to keep a deal moving, and buyers can also buy points themselves on any purchase or refinance. The phrase to watch is free: nothing in a transaction is actually free, so look at how the incentive interacts with the base price, the rate the preferred lender quotes, and the fees in the Loan Estimate. The Consumer Financial Protection Bureau's guidance on points and lender credits is worth reading before you choose, because the same dollar can be a rate discount or a credit that raises your rate.

Is a buydown the right trade for you?

• Hold period matters. A permanent buydown rewards owners who stay; if you expect to refinance or sell within a few years, the breakeven may not arrive before you leave.
• Temporary help fits a rising income. If year one is the tight year and year three is comfortable, a 2-1 buydown shapes payments to your trajectory.
• Compare Loan Estimates, never headlines. Get the builder's preferred lender and your own lender at the same rates and fees on the same day, incentive included.
• Watch the price. A hefty incentive can be paired with a higher base price, so the true question is total cost, not the size of the credit.
• Ask what happens in year three. Know the full note rate and its payment before you fall in love with year-one numbers.

Why builders use buydowns so often right now

With the 30-year fixed average reported near 7.03 percent by Freddie Mac in late September 2026, builders use buydowns to lower the effective payment and keep move-in ready inventory turning. The results can be striking: David Weekley Homes has advertised starting rates as low as 3.99 percent on select move-in ready homes in the Charleston area, a promotional rate attached to specific houses and terms. The spread between a promotional rate and the prevailing average is exactly where a buydown's value lives, and also exactly where the fine print matters.

I map this onto the active Cane Bay and Nexton builder lineup in my new construction guide to those two communities .

For the bigger rate picture, this piece on what rising mortgage rates mean for buyers and sellers connects the market news to your decision.

The bottom line

A buydown is a timing tool, not a magic number. It moves dollars from your closing table or the builder's budget into your monthly payment for a set window, or spends points to lock in a permanently lower rate. Both versions can be genuinely good deals, and both can be marketing dressed up. The difference shows up in one document: the Loan Estimate. Read it line by line, and ask for the year-three payment before you choose.

My Charleston buying guide walks the full process from pre-approval to closing.

Buying for the first time? The first-time buyer hub covers money, neighborhoods, and new construction in one curriculum.

Rates, buydown costs, point prices, and incentive terms in this article are estimates from public sources as of the reporting date and change frequently. Verify every figure with your lender's Loan Estimate, the builder, and current rate data before you commit. This article is general education and not lending, tax, or appraisal advice.