Mortgage Rate Buydowns and Rate Locks: What Seattle Buyers Should Actually Understand

What a Mortgage Rate Buydown Actually Does

A rate buydown lowers your effective interest rate, either temporarily or permanently, by paying money upfront — either as points paid by you, or as a concession funded by the seller or builder. The mechanics differ meaningfully depending on which type you're offered, and the two are frequently confused in casual conversation despite serving very different purposes.

Temporary Buydowns: 2-1 and 3-2-1 Structures

A 2-1 buydown reduces your rate by two percentage points in the first year and one percentage point in the second year, before reverting to the original note rate for the remainder of the loan. A 3-2-1 structure extends this over three years with a larger initial reduction. These are typically funded by a lump sum placed in an escrow account at closing, which is drawn down each month to subsidize your lower payment.

This structure makes the most sense for buyers who expect their income to grow, or who are betting on refinancing before the reduced-rate period ends — if neither is true, you're simply deferring your true payment rather than reducing it.

Permanent Buydowns: Paying Points for the Life of the Loan

A permanent buydown means paying discount points upfront to lower your interest rate for the entire term of the loan, rather than just the first year or two. The math here depends entirely on your break-even point — how long it takes the monthly savings to recoup the upfront cost — measured against how long you actually expect to hold the loan.

Buyers who plan to stay in a home for a long time benefit more from a permanent buydown than buyers who expect to move or refinance within a few years, since the upfront cost needs time to pay for itself.

Who Typically Pays for a Buydown — And When Sellers Offer One

In a market where sellers are more willing to negotiate, a temporary rate buydown has become a common concession — sellers fund it in lieu of a price reduction, which can be more valuable to a buyer than the equivalent cash off the purchase price, since it directly reduces monthly payments during the years they may be most budget-sensitive.

This is worth raising specifically in your own offer negotiation rather than assuming it's off the table — a seller-funded buydown is often easier for a seller to agree to than an outright price cut, since it doesn't affect the recorded sale price.

Rate Locks and Float-Down Options

A rate lock guarantees your quoted interest rate for a defined window — commonly 30 to 60 days — protecting you from rate movement while your loan moves through underwriting to closing. Locking too early risks the lock expiring before closing; locking too late risks rate movement working against you during a critical window.

Some lenders offer a float-down option, allowing you to capture a lower rate if the market improves after you lock but before you close, typically for an additional fee or built into specific loan products. Ask your lender directly whether this is available — it is not automatic or universal, and it's easy to assume you have this protection when you don't.

Running the Real Math Before You Choose a Buydown

Before accepting any buydown structure — whether self-funded or offered as a concession — ask your lender for the actual break-even calculation: how much the buydown costs, how much it saves monthly, and at what point those savings exceed the upfront cost. This calculation should factor in your realistic plans to stay in the home, not just the most optimistic scenario.

For a seller-funded temporary buydown specifically, also compare it directly against an equivalent price reduction — in some cases the price reduction is actually the better deal once you account for how the buydown funds are structured, and a good lender should be willing to run both scenarios for you.

Common Mistakes Buyers Make With Buydowns and Locks

Assuming a temporary buydown solves an affordability problem rather than defers it: if your income won't realistically grow enough to absorb the reverted rate, a 2-1 buydown is postponing a payment shock rather than preventing one.

Not asking about float-down availability before locking: buyers who lock without asking sometimes assume they're protected against a rate drop when their specific loan product doesn't include that option.