12 Claire Court, St Martins Drive, Walton On Thames, KT12 3BW

12 Claire Court is a one-bedroom end-of-terrace house in Walton On Thames (KT12 3BW). It has a recorded floor area of 47 m² (around 506 sq ft), construction records dating it to 1967-1975 and council tax band C. The latest certificate (February 2020) shows an F (score 25), near the bottom of the EPC scale. The rating has held steady at F across 2 certificates since November 2009. Between certificates, lighting went from Very Poor to Very Good; while wall efficiency dropped from Average to Poor and roof efficiency dropped from Poor to Very Poor. The recommended improvements would lift it to C (score 73), a 3-band jump. Main heating runs on electricity. At 47 m² this is the 11th smallest of 14 units on EPC record in the building, where floor areas span 41–59 m². The building's EPC ratings span F to D, with this unit at the bottom. On EPC score it ranks last in the building (25 versus a best of 67).

Held since February 2003 — that's 23 years off the open market, well above the local norm. Across the public record there are 4 sales, relatively high churn for a single property. On energy efficiency it sits in the bottom 10% of properties in this postcode — significant headroom for improvement. Across 1996–2003, sale prices on this property compounded at 18.2% per year. Today's modelled estimate of £238,000 sits 66.4% above the 2003 sale of £143,000. On a £-per-square-foot basis, the last sale (£283/sq ft) was about 18.1% below the postcode norm.