21a, Forest Drive West, London, E11 1JZ

21a is a mid-terrace house in London (E11 1JZ). It has a recorded floor area of 48 m² (around 517 sq ft), construction records dating it to before 1900 and council tax band B. The latest certificate (June 2017) shows a C (score 76), near the top of the C band. When first surveyed in November 2008 the rating was D, the property has climbed 1 band since. Between certificates, wall efficiency went from Very Poor to Good, window efficiency went from Very Poor to Good and lighting went from Poor to Very Good. At 48 m² this is the 26th smallest of 45 units on EPC record in the building, where floor areas span 15–141 m². The building's EPC ratings span E to B across 45 units on file.

Untraded for 26 years, with the last transfer in December 1999. Only one transfer is on record with HM Land Registry, suggesting it has stayed in the same hands for a long time. Today's modelled estimate of £359,000 sits 498.4% above the 1999 sale of £59,995. On a £-per-square-foot basis, the last sale (£116/sq ft) was about 61.7% below the postcode norm.