Refinance Risk: What Happens If Rates Move Before You Refi

Any strategy built around buying now and refinancing later — BRRRR most explicitly, but also a cash purchase you intend to leverage afterwards, or a bridge loan on any project — has a gap between the day you underwrote the deal and the day the refinance closes. Rates, appraisals and lending standards can all move during that gap, and unlike the purchase price, none of them are fixed until the new loan funds.

The three things that can move

1. Interest rates

The refinance rate you underwrote at purchase is an assumption, not a commitment. Nothing locks it in until you close the new loan, often months later. If rates rise during the rehab and hold period, the new payment comes in higher than planned, and that reduces the cash flow the whole deal was built around.

A point of rate costs about $119 a month here, or roughly $1,430 a year, every year for thirty years. It is frequently enough to turn a modestly cash-flowing property into a break-even or negative one without anything about the property changing. These figures are illustrative — a teaching example, not market data for any particular city.

2. The appraisal

Your after-repair value at purchase is your own number, informed by comparable sales. The refinance appraisal is someone else's, and it is the one that counts. Because the new loan is capped at a percentage of appraised value, a conservative appraisal reduces the loan directly, which reduces how much cash comes back out. This is the single most common reason BRRRR deals leave more capital in than planned.

Note the leverage in that table working against you: because the loan is a fraction of value, a 10% miss on the appraisal costs $17,250 of cash out — but since it is cash you were relying on for the next deal, the proportional damage to your plan is larger than 10%.

3. Lending standards

Minimum coverage ratios, maximum loan-to-value limits and documentation requirements are not fixed; they move with the broader lending environment. A refinance plan built around today's typical terms can meet tighter standards by the time you are ready to close, and the longer the rehab timeline, the more opportunity there is for that to happen.

Seasoning requirements belong in this category too. Many lenders will not lend against a property's new value until you have owned it for a minimum period, and that period is a policy rather than a law — it can change, and it differs between lenders and between programs at the same lender.

The fourth thing, which is you

The three risks above are about the market. The fourth is personal, and it catches people who did everything else right: your own circumstances can change between purchase and refinance in ways that affect whether you qualify.

A job change, a drop in credit score, a new car loan, or simply having opened several other mortgages in the interim can all alter the picture — even on a loan underwritten primarily against the property, since credit and reserves are still examined. The practical defence is to avoid taking on new debt or changing employment during a rehab if you can help it, and to be honest about whether your qualifying profile is stable for the length of the project.

What a rate lock does and does not do

A rate lock fixes the rate for a defined window — commonly measured in weeks rather than months — and it attaches to a specific loan application in progress. It is not something you can obtain at purchase for a refinance you intend to do next year.

That is the heart of the problem: the exposure runs from the day you commit to the purchase until the day a refinance application can realistically be locked, and nothing bridges it. Extended locks and float-down options exist on some programs and cost money, and they are worth asking about near the end of a rehab, but they do not help with the months before that.

How to underwrite around it, not hope around it

• Stress-test the refinance rate. Run the numbers at today's rate and at a point or more higher. If the deal only works at today's rate, that is exposure rather than a margin of safety.
• Use a conservative appraisal. Underwriting to a value below your optimistic estimate builds in room for the appraiser to disagree, which they frequently will.
• Keep the timeline tight and realistic. Every additional month is another month of exposure — and padding a rehab schedule "to be safe" actually extends the window rather than protecting you in it.
• Confirm seasoning before you buy. Ask the lender you intend to refinance with, not the one financing the purchase.
• Have a fallback. Know in advance whether you could carry the original financing longer, bring cash to the refinance, or hold the property as it is.

What a fallback actually looks like

"Have a plan B" is easy to say and worth making concrete, because the plausible fallbacks are few. You can bring cash to the closing to make up the shortfall, which works if you have it and defeats the purpose if that cash was the next deal's down payment. You can accept a smaller refinance and leave more capital in the property, which is survivable provided the property cash flows at the smaller loan. You can extend or re-finance the short-term loan, which is expensive but buys time for an appraisal to improve or rates to ease. Or you can sell, which converts an investment plan into a flip, with the selling costs that implies.

Deciding which of those you would choose before you need it is the difference between a contingency and a scramble. The one option that does not exist is waiting indefinitely, because the short-term loan keeps accruing the whole time.

Running the numbers

The BRRRR calculator lets you change the refinance rate and after-repair value independently of the purchase, which is the fastest way to see how much of the plan rests on each. The DSCR loan qualifier shows whether the rent would support the new loan at a higher rate, since a refinance has to pass an income test as well as a value test. And our guide to the BRRRR method covers the full sequence these risks sit inside.