IRR Explained for Property Investors

Investment Fundamentals · 7 min read

Internal Rate of Return (IRR) is the gold standard metric for evaluating property investments over time. Unlike annual yield calculations, IRR captures the full lifecycle return: purchase, cashflows, capital appreciation, and exit.

What IRR Measures

IRR is the annualized rate of return that makes the net present value of all cashflows equal to zero. In simple terms: it's the "interest rate" your capital earns over the hold period, accounting for:

✓ Initial investment (negative cashflow)
✓ Annual rental income (positive cashflow)
✓ Operating costs and mortgage payments (negative cashflow)
✓ Capital appreciation
✓ Sale proceeds (final positive cashflow)

Why IRR Matters

IRR answers: "If I hold this property for 5 years, what's my true annualized return?" This allows you to compare property against equities, bonds, or other investments on an apples-to-apples basis.

Example: 5-Year Hold Year 0: -£80,000 (deposit + fees) Year 1-5: +£3,000/year (net cashflow after mortgage) Year 5: +£350,000 (sale proceeds after CGT) IRR = 12.4% annualized

A 12.4% IRR means your capital compounded at 12.4%/year over the hold period — significantly better than a savings account or typical equity returns.

IRR vs Simple ROI

Simple ROI = (Total Profit ÷ Investment) × 100. It ignores time.
IRR = Annualized return accounting for when cashflows occur.

Two properties with identical total profit can have very different IRRs depending on hold period and cashflow timing.

When to Use IRR

✓ Comparing hold vs sell decisions
✓ Evaluating acquisition opportunities
✓ Assessing refinancing impact
✓ Portfolio-level performance review

1st Numbers calculates IRR automatically for each property based on your actual cashflows, valuations, and projected exit scenarios.