9b, Barnsbury Avenue, Aylesbury, HP20 1NL

9b is a one-bedroom semi-detached house in Aylesbury (HP20 1NL). It has a recorded floor area of 42 m² (around 452 sq ft), construction records dating it to 1950-1966 and council tax band B. The latest certificate (May 2019) shows an E (score 54), well below the UK norm with real room to improve. The rating has held steady at E across 2 certificates since February 2009. Between certificates, window efficiency went from Poor to Average, lighting went from Poor to Average and main heating went from Poor to Average. The recommended improvements would lift it to C (score 76), a 2-band jump. Main heating runs on electricity. At 42 m² this is the 4th smallest of 29 units on EPC record in the building, where floor areas span 38–120 m². The building's EPC ratings span F to C across 29 units on file.

Untraded for 24 years, with the last transfer in March 2002. Today's modelled estimate of £166,000 sits 176.7% above the 2002 sale of £60,000. On a £-per-square-foot basis, the last sale (£133/sq ft) was about 36.5% below the postcode norm. At 42 m² it sits well below the postcode median (70 m² across 28 EPCs), making it one of the more compact homes locally. It lags the bulk of the postcode on energy efficiency (less efficient than 82% of similar EPCs).