11a, Addison Grove, Hounslow, London, W4 1EP

11a is a two-bedroom detached house in Hounslow, London, London (W4 1EP). It has a recorded floor area of 90 m² (around 969 sq ft), construction records dating it to 1900-1929 and council tax band E. It is a listed building, which means external alterations are tightly controlled but it may qualify for heritage tax reliefs. Other recorded features include a balcony. Period features are noted in the property record. At 90 m² this is the 4th smallest of 11 units on EPC record in the building, where floor areas span 31–271 m². The building's EPC ratings span F to D, with this unit at the top. The latest certificate (October 2025) shows a D (score 61), on the cusp of jumping into the C band. When first surveyed in March 2009 the rating was E, the property has climbed 1 band since. Between certificates, wall efficiency went from Very Poor to Poor. The recommended improvements would push it to C (score 77).

Held since July 2009 — that's 17 years off the open market, well above the local norm. That sale fell during the post-crash dip, which often skews comparisons against later neighbouring sales. One planning application is currently pending a decision in 2026. The record references listed-building consent, which constrain future alterations. Across 2006–2009, sale prices on this property compounded at 5.8% per year. Today's modelled estimate of £858,000 sits 50.5% above the 2009 sale of £569,950. On a £-per-square-foot basis, the last sale (£588/sq ft) was about 27.1% below the postcode norm. At 90 m² it sits well below the postcode median (136 m² across 10 EPCs), making it one of the more compact homes locally.