Audit the home purchase before the payment becomes permanent.

What is a mortgage affordability audit?

A mortgage affordability audit is a structured review of the full homeownership budget before the buyer commits to a purchase price. It goes beyond principal and interest. The audit looks at property taxes, insurance, PMI, HOA dues, utilities, maintenance reserves, cash to close, other debts, living expenses, emergency savings, and payment increases that may occur after closing.

The purpose is not to decide whether a lender might approve a loan. The purpose is to decide whether the household can live with the home after the loan closes. A household can receive an approval and still be uncomfortable if the payment absorbs savings, leaves no repair reserve, or depends on optimistic tax and insurance estimates.

Use this audit before making an offer, again after receiving a Loan Estimate, and again after inspection. Each round replaces rough assumptions with better information. If the scenario becomes weaker as the numbers become more accurate, the buyer should slow down and review alternatives.

Step 1: Confirm the full monthly housing cost

Start with principal and interest, then add property taxes, homeowners insurance, PMI, HOA dues, utilities, and a maintenance reserve. These items should be reviewed together because they all compete for the same monthly income. If one input is missing, the payment can look safer than it really is.

Taxes deserve special attention. The prior owner's tax bill may not reflect what the buyer will pay after sale, reassessment, exemption changes, or local millage differences. Insurance also deserves a real quote for the specific property because location, roof age, claims risk, coverage level, and underwriting conditions can change the premium.

• Use a real lender estimate for principal and interest when available.
• Use local records or assessor information for property-tax history.
• Request a homeowners insurance quote for the specific address.
• Include PMI if the down payment and loan type require it.
• Include utilities and maintenance reserve even if they are not part of escrow.

Step 2: Review cash to close and cash after closing

Cash to close is not just the down payment. It can include lender fees, title and settlement charges, appraisal, inspection, prepaid interest, insurance, escrow deposits, recording costs, and other local charges. The buyer also needs money for moving, utility setup, immediate repairs, tools, furnishings, and normal reserves after moving in.

The audit should separate three numbers: cash available before purchase, cash required to close, and cash remaining after move-in costs. A buyer who has enough to close but almost nothing left afterward may be exposed to repair debt, credit-card balances, or missed savings shortly after moving.

If post-close cash is too low, test a lower purchase price, more time to save, seller concessions, lender credits, or a different down-payment strategy. Each choice has tradeoffs, so the purpose is to understand the cash position before it becomes urgent.

Step 3: Compare DTI with leftover cash

Debt-to-income ratios are useful, but they do not show the entire household budget. Front-end DTI compares housing cost to gross income. Back-end DTI adds other debt. Leftover cash uses the household's actual monthly budget after housing, debts, and normal living expenses.

A scenario is stronger when all three signals point in the same direction. It is weaker when one number looks acceptable but another shows strain. For example, a buyer may have a reasonable front-end DTI but very low leftover cash after childcare, transportation, medical costs, and debt payments.

• Front-end DTI checks housing pressure.
• Back-end DTI checks total debt pressure.
• Leftover cash checks day-to-day budget flexibility.
• Emergency savings checks whether the household can absorb surprises.

Step 4: Stress-test the first two years

The first payment is not always the long-term payment. Taxes may increase after reassessment. Insurance may rise after underwriting or renewal. Escrow shortages may be collected over a short repayment period. Maintenance needs may appear quickly after inspection items become real projects.

Run a stress scenario with a higher interest rate, higher taxes, higher insurance, and a larger repair reserve. If the budget fails under a modest stress case, the buyer may need a larger cash buffer or a lower purchase price. A strong purchase should not depend on every estimate being perfect.

Step 5: Decide what would make the purchase safer

The audit is most useful when it leads to a practical decision. If the scenario is tight, the answer is not always to abandon the home. The buyer can test a lower price, a larger emergency reserve, a delayed purchase, reduced debt, different loan terms, seller concessions, or a longer timeline for repairs.

The safest answer is usually the one that keeps the household flexible. A buyer should be able to pay the home costs, maintain the property, save for emergencies, and handle normal life without relying on perfect conditions. If the calculator shows a warning, use it as a prompt to improve the plan before making the obligation permanent.

Mortgage affordability audit checklist

• Principal and interest estimated from a real rate and loan term.
• Property tax reviewed for reassessment or exemption changes.
• Homeowners insurance quoted for the specific property.
• PMI included when applicable.
• HOA dues and possible special assessments reviewed.
• Utilities estimated from the property, not the current rental.
• Maintenance reserve included as a monthly cost.
• Cash to close separated from cash left after moving.
• Emergency reserve preserved after closing.
• Front-end DTI, back-end DTI, and leftover cash reviewed together.
• Escrow shock scenario tested for the first two years.
• Inspection findings translated into repair reserves.

After completing the checklist, return to the main true monthly cost calculator and update the scenario with the strongest available numbers.