Equity (home)

Home equity is the difference between a property’s current market value and the outstanding mortgage balance. A $500,000 house with a $350,000 mortgage has $150,000 of equity. The owner can borrow against it (HELOC, cash-out refi), liquidate it on sale, or simply hold it.

Two engines grow home equity:

• Amortisation. Each monthly payment reduces the principal balance, mechanically increasing equity. The pace is front-loaded with interest in the early years — see amortisation — so equity build-up accelerates over the life of the loan.
• Appreciation. If the property’s market value rises, equity rises by the full appreciation amount (the mortgage doesn’t scale up). US home prices have appreciated roughly 4-5% per year long-term, though regional and decade-by-decade variation is large.

Equity is the basis of several common moves:

• Cash-out refinance — increase the mortgage balance to pull cash out of accumulated equity. Costs roughly the same as a regular refinance plus a slightly higher rate.
• Home equity line of credit (HELOC) — a revolving credit line secured by the equity, typically at variable rates 1-3% above the prime rate.
• Sale. Equity converts to cash at closing (minus transaction costs of typically 6-8% in the US).

Important caveat: equity is illiquid. Tapping it costs money (closing fees, interest on the borrowed amount) and carries risk (you’re leveraging a depreciating asset if the market turns). Most financial planners treat home equity as a separate bucket from liquid net worth.

Worked example

Bought a $500,000 house with 10% down ($50,000), a $450,000 mortgage at 7% over 30 years. Initial equity: $50,000. After year 5: the principal balance has fallen to about $423,500 (most of the $2,994 monthly payment went to interest). If the house has appreciated at 4%/year, market value is now $608,300. Equity = $608,300 − $423,500 = $184,800 — almost 4× the original down payment. Of that $184,800: $26,500 came from amortisation (principal paid down), and $108,300 came from appreciation. Sell now and after 7% transaction costs ($42,500), the homeowner pockets ~$142,000 — a 184% return on the original $50,000 in 5 years (28% annualised, before mortgage interest paid). That leverage effect is why real estate generates outsized returns in rising markets — and outsized losses in falling ones, because the same leverage applies in reverse.

One more lever rarely discussed: principal-only extra payments. Sending an additional $200/month against the same $450,000 loan above shaves over 6 years off the term and saves roughly $115,000 in lifetime interest, because each extra dollar paid early avoids decades of compound interest. The mechanism is the inverse of front-loaded amortisation — small extra principal payments in years 1-5 have outsized lifetime impact.

When and why it matters

Equity matters at three decision points: (1) whether to sell or stay, where equity available for the next purchase is the constraint; (2) whether to refinance and cash out, where the lender will lend up to ~80% of current appraised value minus existing mortgage; (3) whether to retire — for many US retirees, home equity is the largest single asset and the decision to downsize or take a reverse mortgage hinges on its size. The mistake to avoid is treating home equity as liquid wealth — until you sell, refinance, or borrow against it, the equity number is just an estimate of what the market would pay on a hypothetical day. The 2008 crisis reduced US home equity by roughly $7 trillion over 18 months; homeowners who had counted on equity for retirement faced abrupt reframing. Conservative financial planning treats home equity as a separate, illiquid bucket from investment portfolios. Reference: CFPB — Owning a Home guide.

The 2008 underwater-mortgage lesson: when home prices fell 20-40% from their 2006 peak across US metros, millions of homeowners ended up with negative equity — mortgages exceeding the home’s market value. The CoreLogic data put the underwater share at 22% of US mortgages at the worst of the crisis. Negative-equity borrowers couldn’t refinance (no lender will refinance a loan worth more than the collateral) and couldn’t sell without bringing cash to closing, which trapped many in unfavourable rates for years. The structural takeaway: equity is volatile, not durable; conservative LTV at purchase (≤ 80%) is the buffer against this scenario. Reference: Federal Reserve — The Housing Bust and Household Balance Sheet Adjustment (2014).