The capitalisation rate — universally shortened to cap rate — is the central valuation metric in commercial real estate and increasingly applied to residential portfolios. It is also one of the most misquoted figures in investment conversations. Understanding its construction prevents expensive misreadings.
1. The Formula and Its Logic
Cap rate equals net operating income divided by current market value, expressed as a percentage. Net operating income (NOI) is gross income minus operating expenses, excluding mortgage payments and depreciation.
A £1,200,000 office unit generating £78,000 in NOI carries a cap rate of 6.5%. That single number encodes the market's assessment of risk and return at a specific point in time for a specific asset class in a specific location.
2. What Drives Cap Rate Compression and Expansion
Cap rates move inversely to property values. When values rise without a proportional increase in income, cap rates compress. When income falls or risk perception rises, cap rates expand.
Several forces drive these movements:
- Interest rate cycles — rising base rates typically expand cap rates as alternative yields compete
- Asset class sentiment — logistics and life sciences currently attract capital that compresses their cap rates
- Lease structure — long-indexed leases with institutional tenants command lower cap rates than short-let retail
- Location premium — prime city-centre assets trade at tighter cap rates than equivalent peripheral assets
- Physical condition and EPC rating — properties requiring capital expenditure attract expanded rates to compensate buyers
In the current cycle, secondary office assets in regional markets have seen cap rates move from 6.5% to 8%+ as occupancy uncertainty has been repriced into values.
3. How to Use Cap Rates in Portfolio Decisions
For residential landlords operating multi-property portfolios, the cap rate framework transfers directly from commercial practice. Calculate NOI for each asset: take achieved rent, deduct agency fees, maintenance reserves, insurance, and service charges. Divide by your acquisition cost or current estimated value.
Tracking cap rates across your portfolio over time reveals which assets are delivering income efficiently and which are underperforming relative to their value. An asset with a falling cap rate is either appreciating without income growth — or its costs are rising faster than rent.
When comparing acquisitions, apply consistent NOI assumptions. Many deal promoters inflate income projections or exclude realistic maintenance allowances. Apply a 10% maintenance reserve as a minimum, and test the cap rate under 90% occupancy rather than full occupancy.
4. Cap Rate Benchmarks by Sector (UK, 2026)
Benchmarks shift with market conditions, but the following ranges reflect prevailing investor expectations in early 2026:
- Prime London residential (multi-unit blocks): 3.8–4.5%
- Regional city-centre BTL portfolios: 5.2–6.8%
- Industrial and logistics: 5.0–6.2%
- High street retail (secondary locations): 7.5–10%+
- Student accommodation: 5.5–7.0%
These are reference points, not guarantees. Individual assets will deviate based on covenant strength, lease terms, and physical quality. The value of the cap rate framework lies not in the benchmark alone but in the discipline it imposes on income analysis — forcing investors to look at net figures rather than headline rents.
Model your portfolio's weighted average cap rate annually. If it is drifting down while property values stagnate, your income efficiency is deteriorating. If it rises alongside values, you are building a genuinely stronger income base.