Flat 5, 139 Sidney Road, Walton On Thames, KT12 3SA

Flat 5 is a one-bedroom semi-detached house in Walton On Thames (KT12 3SA). It has a recorded floor area of 49 m² (around 527 sq ft), construction records dating it to before 1900 and council tax band C. The latest certificate (June 2020) shows an F (score 37), near the bottom of the EPC scale. Earlier certificates rated it D (September 2009); the latest reading is 2 bands lower. Between certificates, window efficiency went from Poor to Good and lighting went from Very Poor to Very Good; while hot-water efficiency dropped from Average to Very Poor and main heating dropped from Average to Very Poor. The recommended improvements would lift it to C (score 79), a 3-band jump. Main heating runs on electricity. At 49 m² this is the 2nd smallest of 5 units on EPC record in the building, where floor areas span 48–56 m². The building's EPC ratings span F to C, with this unit at the bottom. On EPC score it ranks last in the building (37 versus a best of 73).

Held since December 1999 — that's 26 years off the open market, well above the local norm. At 49 m² it sits well below the postcode median (130 m² across 32 EPCs), making it one of the more compact homes locally. On energy efficiency it sits in the bottom 10% of properties in this postcode — significant headroom for improvement. Across 1999–1999, sale prices on this property compounded at 59.3% per year. Today's modelled estimate of £230,000 sits 109.2% above the 1999 sale of £109,950. On a £-per-square-foot basis, the last sale (£208/sq ft) was about 41% below the postcode norm.