5a, Witham Road, Isleworth, TW7 4AJ

5a is a semi-detached house in Isleworth (TW7 4AJ). It has a recorded floor area of 84 m² (around 904 sq ft) and construction records dating it to 1900-1929. The latest certificate (June 2015) shows a D (score 60), on the cusp of jumping into the C band. When first surveyed in January 2009 the rating was E, the property has climbed 1 band since. Between certificates, window efficiency went from Poor to Average; while hot-water efficiency dropped from Very Good to Good and lighting dropped from Average to Very Poor. The recommended improvements would push it to C (score 76). The latest certificate is from June 2015, so improvements made since then won't be reflected. At 84 m² this is the 4th smallest of 13 units on EPC record in the building, where floor areas span 51–214 m². The building's EPC ratings span D to C, with this unit at the bottom.

Held since December 2006 — that's 19 years off the open market, well above the local norm. Across 1999–2006, sale prices on this property compounded at 11.9% per year. Today's modelled estimate of £406,000 sits 80.4% above the 2006 sale of £225,000. On a £-per-square-foot basis, the last sale (£249/sq ft) was about 16.7% below the postcode norm. At 84 m² it sits well below the postcode median (130 m² across 12 EPCs), making it one of the more compact homes locally.