Basement Flat, 5 Martell Road, Lambeth, London, SE21 8EA

Basement Flat is a one-bedroom semi-detached house in Lambeth, London, London (SE21 8EA). It has a recorded floor area of 47 m² (around 506 sq ft) and construction records dating it to 1900-1929. The latest certificate (December 2022) shows a D (score 67), on the cusp of jumping into the C band. The recommended improvements would push it to C (score 78). Period features are noted in the property record.

Held since September 2007 — that's 19 years off the open market, well above the local norm. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. Across 1997–2007, sale prices on this property compounded at 14.6% per year. Today's modelled estimate of £351,000 sits 71.2% above the 2007 sale of £205,000. At 47 m² it's 17.5% smaller than the typical home in the postcode (57 m² median across 20 EPCs). It lags the bulk of the postcode on energy efficiency (less efficient than 70% of similar EPCs).