Direct answer

The result depends on the written lock agreement. The borrower may face an extension charge, revised terms, loss of a float-down opportunity, or a new market rate. Responsibility for extension costs may also depend on the builder agreement or promotion.

Before locking, ask who monitors the expiration, what an extension costs, whether the rate can improve, and how much construction delay the strategy can absorb.

What does this mean for a Northeast Florida buyer?

In Northeast Florida, the answer should be tested against the builder's actual contract, community, expected completion range, taxes, insurance, HOA or CDD obligations, and the buyer's current approval. Jacksonville, St. Johns, Clay, Nassau, and Flagler County transactions do not share one universal cost or timeline.

Primary sources

Where can you verify the framework?

  1. Explore mortgage interest ratesConsumer Financial Protection Bureau · Accessed August 13, 2026
  2. Compare and negotiate your loan offersConsumer Financial Protection Bureau · Accessed August 13, 2026