21a, Penn Road, Islington, London, N7 9RD

21a is a semi-detached house in Islington, London, London (N7 9RD). It has a recorded floor area of 91 m² (around 980 sq ft), construction records dating it to 1900-1929 and council tax band A. The latest certificate (November 2020) shows an E (score 51), well below the UK norm with real room to improve. Earlier certificates rated it C (April 2009); the latest reading is 2 bands lower. Between certificates, window efficiency went from Very Poor to Poor and lighting went from Very Poor to Very Good. The recommended improvements would lift it to C (score 78), a 2-band jump. At 91 m² this is the 15th smallest of 32 units on EPC record in the building, where floor areas span 38–256 m². The building's EPC ratings span G to C across 32 units on file.

It hasn't traded since August 1998, a hold of 28 years that's notably long for the area. Only one transfer is on record with HM Land Registry, suggesting it has stayed in the same hands for a long time. At 91 m² the property is well over the postcode median (62 m² across 49 EPCs), placing it in the larger end of the local stock. It lags the bulk of the postcode on energy efficiency (less efficient than 82% of similar EPCs). Today's modelled estimate of £680,000 sits 372.2% above the 1998 sale of £144,000. On a £-per-square-foot basis, the last sale (£147/sq ft) was about 71% below the postcode norm.